CHAPTER 4
Horticultural Varieties of Citrus
BY ROBERT WILLARD HODGSON
HORTICULTURAL CLASSIFICATION
In general appearance and other respects, the citrus fruits of
principal commercial importance fall into four, reasonably-well-defined
horticultural groups: the oranges, the mandarins, the pummelos and
grapefruits, and the common acid members. The common acid
group includes three subgroups—the citrons,
lemons, and limes. While the writer's competence does not
extend to all the citrus fruits that have horticultural importance, the
considerable number with which he is acquainted all exhibit
horticultural resemblances with one or more of these groups and
subgroups that suggest some degree of relationship. In most
instances, it is not difficult to determine the group of closest
resemblance and probable or possible relationship.
Therefore, in this treatment, for each of the natural groups presented
there is a subsection covering fruits of horticultural importance that
most closely resemble the group in question. In some
instances, however, lack of first-hand acquaintance with a fruit has
necessitated provisional placement.
In addition to the fruit groups mentioned above, all of which belong to the genus Citrus, there are the kumquats, which belong to the closely related genus Fortunella, and the so-called but much more distantly related trifoliate orange, Poncirus trifoliata (L.)
Raf. The kumquats comprise a group of considerable
importance for their fruits. The trifoliate orange, together
with its hybrids, is of significance as a rootstock.
The Oranges.—The
principal members of the orange group are the sweet orange and the
bitter orange, which though similar in many respects have important differences.
Four kinds of sweet oranges are recognized:
1. The common orange (blond orange of the Mediterranean), which is
much the most important of the four and contains a large number of
varieties.
2. The sugar or acidless
orange, which is of minor importance and so lacking in acid that it is
insipid in flavor.
3. The pigmented
or blood orange, which is of considerable importance in Europe and
includes two categories: (a) the light blood oranges; and (b) the deep
blood oranges.
4. The navel orange,
which is of great importance and represented mainly by the Washington
navel variety.
The following three kinds of fruit are recognized among the bitter or sour oranges proper:
1. The common bitter or sour orange that is used principally as a
rootstock and for the preparation of marmalade.
2. The bittersweet orange, the fruit of which is similar to the common
bitter orange but less acid.
3. The
variant bitter oranges, grown primarily as ornamentals and for the
flowers, from which neroli oil is extracted.
Mediterranean fruits of horticultural importance that are obviously
closely related to the bitter orange include:
1. The myrtle-leaf orange or chinotto, grown mostly as an ornamental.
2. The bergamot, grown primarily for its distinctive rind oil that
constitutes the base of cologne water and has other perfumery uses.
Oriental fruits that more closely resemble the bitter orange than any other include the Naruto and Sanbô of Japan, the Kitchli of India, and the Nanshôdaidai of Taiwan.
The Mandarins.—Because
of the remarkable diversity of the mandarins and the writer's lack of
first-hand knowledge of many of the Oriental members, considerable
difficulty was experienced in developing a satisfactory horticultural
classification for this group. In this treatment, therefore,
the mandarins are presented in the following classes:
1. The satsuma mandarins (Citrus unshiu Marcovitch), which are of great importance in Japan and consist of many varieties.
2. The King mandarins (Citrus nobilis Loureiro), which have considerable importance in southeast Asia but contain few varieties.
3. The Mediterranean mandarin (Citrus deliciosa Tenore), which is of principal importance in the Mediterranean basin.
4. The common mandarins (Citrus reticulata Blanco), which have worldwide importance and are represented by numerous varieties.
5. The small-fruited mandarins, which are of considerable importance in
the Orient and consist of many varieties.
The mandarin-like fruits include the synthetic tangors; the so-called
natural tangor, Temple; many of the synthetic tangelos; the so-called
natural tangelo, Ugli; and the Calamondin and Rangpur of the Orient, the latter of which includes the varieties Kusaie and Otaheite.
The Pummelos and Grapefruits.—While
similar in many respects and overlapping in certain characters,
horticulturally the pummelos and grapefruits comprise separate classes,
each of which consists of both non-pigmented and pigmented
varieties. Additionally, the pummelos contain both common
acid and acidless or sweet varieties.
Fruits that more resemble the grapefruit or pummelo than any other
include a number of synthetic tangelos; the so-called natural orangelo, Chironja of Puerto Rico; the Poorman, Smooth Seville, and Wheeny grapefruit of Australia; and the Natsudaidai, Hassaku, Banokan, Hyuganatsu, Kinkôji, and Kinukawa of Japan; and the Attani of India.
The Citrons.—The
citrons, like the other members of the common acid group, fall into two
classes—the acid and the sweet—each of which contains several
varieties.
Fruits more resembling
the citron than any other include the so-called Cuban shaddock and
Ponderosa lemon, the lumias of the Mediterranean, and the giant-fruited citrons of India.
The Lemons.—The lemons, like the citrons, consist of the common or acid varieties, which are numerous and important, and the comparatively few and minor sweet or acidless varieties.
Of the fruits that most closely resemble the lemons, those of principal
horticultural importance are the limettas of the Mediterranean, the jamberi or rough lemon, the galgal and karna of India, and the so-called Meyer lemon of China.
The Limes.—Like the citrons and lemons, the limes include both acid and sweet varieties, but
in addition the sour limes consist of two kinds—the small-fruited
Indian, West Indian, or Mexican lime and the large-fruited Tahiti or
Persian lime, both of which have very few varieties.
The lime-like fruits of principal horticultural importance include the
synthetic lemonime, Perrine; several so-called lemons in India that
appear to be natural lemonimes; and the bigeneric limequats (lime X
kumquat), of which there are a few lime-like varieties.
The Kumquats.—The principal fruits of horticultural importance or interest of the genus Fortunella are
several kinds or varieties of the kumquat, the bigeneric, so-called
orangequat, and the trigeneric citrangequats, of which there are a few
varieties.
The Trifoliate Orange.—Of the genus Poncirus, the
trifoliate orange and some of its bigeneric hybrids—notably the
citranges—are important primarily for their value as
rootstocks. A few of the citranges also approach edibility.
THE NATURE AND CONSTANCY OF CHARACTERS IN CITRUS
Fruit and Tree Characters
In addition to the common characters possessed by other fruits, such as
size, shape, color, form of the basal (stem) and apical (stylar) ends,
flavor, and general seed features, the citrus fruits exhibit certain
characters associated with: (1) the anatomy of the distinctive
hesperidium fruit; (2) their degree of parthenocarpy; and (3) their
degree of polyembryony. Among the distinctive anatomical
characters are those relating to the rind (flavedo and albedo) and
inclusions (oil glands), the endocarp (fruit segments and juice
vesicles), the central column or axis, and special structures that are
or may be present in the apex (areole, mammilla,
navel). Seedlessness characterizes certain groups and
varieties and monoembryony is exhibited by some.
External Fruit Characters.—Citrus
fruits range in size from very small to very large. Among
the smallest are the kumquats, Calamondin, and some of the acid limes,
the greatest dimension of which may scarcely exceed an inch and a
quarter (3 cm). At the other extreme are the pummelo and
citron which may attain a foot (30 cm) or more in diameter or
length. While the largest of the citrus fruits are pummelos,
the heaviest are citrons because of their much greater rind
density. Some citrons attain weights of 10 to 12 pounds
(approximately 4,500 to 5,550 grams). Considering the citrus
fruit groups as a whole, generally the oranges are medium-small to
medium in size, the mandarins small to medium, the grapefruits
medium-large to large, the lemons medium-small, the acid limes very
small to small, the pummelos large to very large, and the citrons
medium-large to very large. The size range within each fruit
group is variable, however, and is greatest in the mandarins, pummelos,
limes, and oranges, each of which has varieties of smaller or larger
size than the group average. These are referred to as
small-fruited or large-fruited varieties of each group.
The shapes exhibited by the citrus fruits (fig. 4-1)
range from round through subglobose and oblate to obovoid on one
extreme and from broadly pyriform to ovoid, oblong, elliptical, and
cylindrical on the other. In general, the oranges are round
or slight modifications thereof, the mandarins oblate, the grapefruits
and pummelos subglobose, the lemons elliptical, and the limes
oval. The citrons are highly variable but mostly cylindrical,
and some of the pummelos are pyriform.
Superimposed on the general shape, and in some cases contributing
thereto, are the basal and apical characters that may be
present. These characters may be rounded, flattened, or
depressed in form, the latter form giving rise to a
basin. Likewise, they may be furrowed or
ribbed. Other basal characters that may occur include a neck,
shoulder, or collar. Other apical characters include the areole,
which may be so indistinct that it is not evident, a nipple (mammilla),
or a navel. The neck character seems to occur oftenest in
the lemons and mandarins and the navel most often in the oranges and
mandarins. The mammilla appears to be confined largely to the
limes, lemons, and citrons. In a few fruits, notably some of
the citrons and the bergamot, a certain percentage of the fruits retain
the style.
The smoothness of the rind
surface, which is highly variable, is in part determined by the size
and position of the oil glands in the flavedo, which may give rise to
small papillae or pits. In addition, the rind may be rough,
wrinkled, bumpy, or ribbed. Most of the citrons exhibit the
bumpy rind character, and many lemons are more or less ribbed.
The primary color of the citrus fruits ranges from pale yellow to
orange-red. The limes, lemons, citrons, grapefruits, and
pummelos exhibit varying shades of the former and the oranges and
mandarins of the latter. Superimposed on the primary color
are various shades of pink or red exhibited by the pigmented grapefruits
and pummelos and the blood oranges.
Internal Fruit Characters.—For
the most part, the internal characters of the citrus fruits are related
to the distinctive structure of the hesperidium and concerned with the
rind, fruit segments and inclusions, the central axis or medulla, and
the seeds.
For the citrus fruit groups
as a whole, the range in both thickness and consistency of the rind is
very great—from the extremely thick rind of some of the pummelos and the
citrons to the very thin peel of the Indian acid lime, and from
the soft, spongy nature of the albedo of the pummelo to the hard, dense
fleshiness of the albedo of the citrons. The range within
each fruit group is also variable, giving rise to both thin-skinned and
thick-rinded varieties. The greatest range in rind thickness
is exhibited by the pummelos, citrons, and
mandarins. Likewise, the range in degree of adherence of the
rind to the fruit segments is very great—from the citrons, in which it
cannot be separated by peeling, to the mandarins, in some of which it is
almost completely loose at full maturity.
Characters relating to the oil glands (in the flavedo) and their
contents are also highly variable and appear to be distinctive for many
of the citrus fruits. These include the number, shape, size,
arrangement, and position of the oil glands, and the kind, amount, and
aroma of the oils. Some of the aromas may be quite
distinctive—fragrant as in the lemon or pungent as in the bitter orange.
Among the principal characters of the edible portion of the fruit or
pulp are the number of segments and the degree of their adherence to
each other, the texture of the carpellary membranes, the form, size, and
texture of the juice sacs or vesicles, and the color, amount, and
flavor of the juice. The number of segments averages highest
in the pummelos, grapefruits, and citrons, and lowest in the kumquats,
Calamondin, and acid limes. The number of segments in the
other fruits is intermediate. Their attachment to each other
is tightest in the citrons and loosest in the mandarins. The
juice vesicles vary greatly in size and form, somewhat in texture, and
are distinctive for many of the citrus fruits. In general,
juice color corresponds somewhat with rind color, the range extending
from pale green in the acid limes to deep orange in some of the oranges
and mandarins. Juice color is light to deep pink in the
pigmented grapefruits and pummelos and may be dark red in the deep blood
oranges. The flavor of the juice varies greatly, depending
principally on the total soluble solids content, the sugar-acid ratio,
and the nature and content of essential oils. Flavor ranges
from insipid or flat to sweet, rich, or sour. In some fruits,
there is a characteristic mild to strong bitter
aftertaste. A pleasant aroma characterizes the juice of some
of the mandarins and oranges.
The
size and solidity of the central column (columella or core) varies
greatly at maturity and may be somewhat affected by climate and other
factors. In most of the citrons and pummelos, it is very
large, while in the acid limes it is quite small. In some
fruits, such as the acid limes and citrons, the column retains its
solidity as the fruit develops, whereas in the mandarins it breaks down
early and at maturity all that remains are the vascular bundles which
traverse it. It may therefore be solid (closed), semi-solid,
or hollow (open). One of the distinctive differences between
sweet and bitter oranges consists in the much greater degree of openness
of core exhibited by the latter.
The
seed content of citrus fruits is highly variable and for some groups and
varieties constitutes a distinctive character, although it may also be
affected by climate and other factors. Thus, the navel
oranges, satsuma mandarins, and a few other varieties are usually
seedless, since they rarely produce viable ovules and
pollen. Even though viable pollen is produced in abundance,
many of the principal varieties regularly produce few or no viable
ovules and hence are commercially seedless (none to ten
seeds). When self-pollinated, some varieties are nearly
seedless, whereas they are seedy when cross-pollinated. In
the seedy varieties, the number of seeds may range from one to four or more per fruit segment.
The seeds are highly distinctive for the different citrus fruits and
vary greatly in size, shape, surface texture, and somewhat in
color. Internal characters include color of the inner seed
coat, the chalazal spot and cotyledons, and the degree of
polyembryony. The pummelos and citrons are regularly
monoembryonic, whereas the grapefruits, Indian acid lime, and many of
the mandarins are highly polyembryonic. The oranges and
lemons are usually intermediate.
Tree Characters.—Normal
season of maturity is a varietal character of great importance that is
determined by the interaction of the environment and the total heat
requirement of the tree. While, as might be expected, the
citrus fruits as a whole are characterized by a wide range in heat
requirement for fruit maturity, some of them—notably the mandarins and
sweet oranges—exhibit surprisingly large differences in varietal
heat requirement. As a consequence, there are very early,
early, midseason, and late-maturing varieties for both of these fruits,
extending over a maturity period of several months. Of
importance in this connection is still another varietal character
determined by the tree: the ability to hold or store the fruit for a
lengthy period without appreciable impairment in quality or loss from
dropping. The Valencia orange variety is outstanding in this
regard.
The range of variation in tree
growth habit exhibited by the citrus fruits as a whole is very
wide—from the straggly, shrub-like citron to the large, highly
symmetrical trees of most of the sweet oranges and grapefruits and some
of the mandarins. Within each fruit group, however, the range
of growth habit is highly variable. The grapefruits and
sweet oranges show the narrowest range and the mandarins the
widest. Certain varietal groups, such as the satsuma
mandarins and navel oranges, are characterized by growth habits so
distinctive that they are useful in identification. This is
true also of certain groups of lemon varieties, with particular
reference to vigor, density of foliage, and degree of
thorniness. In addition, some varieties of oranges and
mandarins have leaves of distinctive size, form, color, or other
features.
Descriptive Terms, Definitions, and Forms.—Because
it remains the best presentation available in English and may therefore
be of value to teachers, students, and technicians, Webber's (1943) outline for the description of citrus fruits is reproduced.
The foregoing outline is designed for use as a printed
blank. Under each heading the most common descriptive terms
are given so that in describing a fruit sample the terms applying can be
checked. If the fruit varies in a certain character, the two
or more descriptive terms applicable should be checked. The
outline is clear in most details, but a few characters may require
explanation. Definitions of most of the terms used may be
found in botanical glossaries and dictionaries.
Color should be carefully compared when possible with some standard
color charts, such as those of Ridgway (1912).
The D/H index given under size is obtained by dividing the diameter of a
fruit by its height (distance from stem to apex). The
average D/H is obtained by totaling the indices of all the individual
fruits measured and dividing by the number of fruits.
The descriptive terms applied to the base of citrus fruits will be readily understood by an examination of figure 4-2.
The areole
is the area at the apex of the fruit which is usually set off by a more
or less distinct circular furrow surrounding the stylar
scar. In descriptions, the circular furrow is referred to as
the areole and the area within it as the areolar area.
The inner seed coat is the membranous covering under the thick,
leathery exterior coat. The chalazal spot is the round area
on the inner seed coat at the chalazal end of the seed, which commonly
is characteristically colored.
The work of Chapot (1955a) in the descriptive pomology of the citrus fruits is outstanding. His monograph on seed characters in Citrus (Chapot and Praloran, 1955) is a contribution of great importance and significance, as are also his numerous other papers.
Constancy of Characters
While the botanical
characters relating to the leaves, flowers, fruits, and seeds are
sufficiently distinctive and constant to permit relatively easy
determination of species, botanical varieties, and certain subspecies
groups, these characters nevertheless exhibit a considerable degree of
variability. Horticultural characters of both tree and
fruit, by means of which varietal identification can be made, are
extremely variable, however, and many of them are highly lacking in
constancy. This results in numerous citrus fruit varieties
which are distinguishable with difficulty, if at all.
Since constancy of citrus characters varies greatly, descriptions
overlap slightly and identification may be somewhat
blurred. Such tree characters as distinctive growth habit, comparative
season of fruit maturity, and ability to store the fruit on the tree
are relatively stable and constant in a subtropical
climate. As would be expected, the most constant fruit
characters are those related to the special anatomical features of the
fruit: the presence or absence and nature of the areole, mammilla, or
navel. Degree of seediness and comparative acidity of the juice are variable, of course, but still reasonably constant. Comparative size and form of the fruit, comparative color,
and thickness and adherence of the rind, while highly variable among
varieties, exhibit a reasonable degree of constancy within a variety and
hence are useful.
Some
citrus tree characters and most fruit characters are markedly affected
by environmental influences. Indeed, these are of very great
importance, for they largely determine the distinctive characteristics
of the fruit upon which market reputation and consumer preference are
based. The principal environmental influences undoubtedly are
climate and rootstock. Soil type and cultural practices may
also affect fruit characteristics, although usually to a minor degree.
Climatic Effects.—Among
tree characters, period of fruit maturity is undoubtedly of greatest
importance and is determined by the nature of the
climate. Thus, the Valencia orange is horticulturally mature
by January in the very hot, dry, low-elevation desert of southern
California, but does not attain maturity until the following June in the
cool, mild, equable coastal valley regions. Ability of trees
to hold their fruit is also affected by the nature of the climate
during and after maturity; this character is minimized by warm night
conditions after maturity. Even certain aspects of tree
growth habit—compactness of tree and density of foliage—are influenced
by climate; these tendencies are accentuated in dry and very cool
climates.
The effects of climate
factors on fruit characters are much more striking, however, and are
sometimes remarkable.
While there are
numerous factors that may affect fruit size, climatic conditions
characterized by high heat and humidity during the growing season make
for large fruit. Thus, the large-fruited Washington navel
orange, which attains ideal size in California, reaches undesirably
large size in the humid, semitropical climates which characterize Brazil
and Florida. In contrast, the small-fruited Hamlin orange
never attains a commercially acceptable size in the arid, cooler
subtropical climate of the southern California coastal region but does
become sufficiently large in Florida and Brazil. In this
general connection, it may be pointed out that the "small fruit" problem
is restricted to medium-sized varieties in arid regions and in seasons
of marginal or below average heat, whereas the "large fruit" problem is
confined to large-fruited varieties in regions or in seasons of
above-average heat or humidity.
Fruit
form may be profoundly modified by climatic factors. In
general, the axis is longer in regions of low atmospheric humidity, and
vice versa. Thus, an oval variety, such as Shamouti orange,
may range from short-oblong (almost round) to long-elliptic depending on
climate. Likewise, the average shape, within any given round
variety of orange, may range from subglobose to oblong, with
accompanying differences in diameter-height (D/H) index from well above 1
to considerably below that value. The factors which function
to increase length of the fruit also appear to favor or accentuate the
tendency to develop a neck in the mandarins and a pyriform shape in the
grapefruits. Therefore, the same variety may exhibit
significantly different fruit forms in regions of different climatic
conditions.
It has long been
recognized that color is markedly affected by the temperature regime
during the ripening period and thereafter. Maximum color
intensity develops when the fruit is subjected to considerable
chilling—normally the result of cold nights. In arid,
subtropical climates, this is assured by the prevalent cool nights
(associated with the wide diurnal fluctuations in temperature) which
characterize the fall and winter months. Primarily because of
warmer nights (associated with small diurnal temperature variations),
color development in semitropical climates is much slower and the
intensity ultimately attained considerably lower, with the possible
exception of some of the mandarins, notably Dancy tangerine.
Other fruit characters materially affected by atmospheric humidity
during the growing season include rind surface, thickness, texture and
adherence, texture of the flesh (juice vesicles and carpellary
membranes), and juice content. Thus, in semitropical regions
such as Florida, the rind is smoother, thinner, softer, and more tightly
adherent, the flesh and carpellary membranes are tenderer, and the
juice content is higher than in such subtropical regions as California.
Flavor is markedly influenced by the same conditions that are primarily
responsible for the intensity of color development, namely, degree of
fluctuation between day and night temperature. Wide diurnal
fluctuation appears to promote sugar accumulation and acid formation,
and vice versa. In general, therefore, the fruit grown in
arid subtropical climates is more strongly and richly flavored than that
produced in semitropical or tropical climates. Fruits or
varieties that are characterized by relatively high acidity, however,
such as the kumquats and some of the mandarins (for example, King and
Kara) and their hybrids (for example, Temple tangor and Minneola and
Seminole tangelos) are more pleasantly flavored in semitropical or
tropical climates, and vice versa. The same seems to be true
with respect to the bitterness that characterizes most of the
grapefruits and some of their hybrids (notably Sampson
tangelo). Since individual tastes differ so greatly, it is
meaningless to argue as to the superiority or inferiority of one over
the other. The important fact is that they exhibit
distinctive differences.
Likewise, the
characteristics of the areole, mammilla, and navel are subject to
climatic modification. In general, these modifications are
more pronounced and prominent in arid than in humid
climates. In the hot semitropics, the areolar furrow, which
may be prominent in the arid subtropics, is usually absent and the
nipple much less well developed or even suppressed to the degree that it
is scarcely discernible, if at all. In subtropical regions,
it has long been recognized that the size and prominence of the navel in
the navel oranges varies considerably among climatic zones, from season
to season, and even between the exterior and interior parts of the
tree.
A most remarkable illustration
of the interactions between climatic factors and fruit characteristics
is afforded by the Nagpur mandarin in central India, where climatic
conditions induce the production of several periods of bloom per year
and, thus, provide a choice of the bloom to be employed—spring or
fall. Many of the growers use the spring bloom for part of
the orchard and the fall bloom for the remainder. The
characteristics of the fruit in the two crops are remarkably
different. The spring-bloom fruit is larger, flatter in form,
paler in color, and notably less acid. Its sugar-acid
ratio averages approximately double that of the fall-bloom
fruit. Bonavia (1888-90) has described numerous other more
striking illustrations in India, where there is doubtless a wider range
of citrus species and forms and of climatic conditions than exists
elsewhere.
Another less spectacular
illustration is exhibited by the lemon, most varieties of which have two
principal periods of bloom—spring and late summer or early fall—but are
more or less everflowering and everbearing. In Italy, the
crops resulting from the flowers produced at various times during the
year have been named and accurately described (Casella, 1935b). There are clearly greater differences between some of them, notably Primofiori (spring) and Verdelli (summer) than between many lemon varieties.
Rootstock Effects.—Although rootstocks may effect growth habit to some degree, their principal effects on tree
characters are concerned with period of fruit maturity and ability of
the tree to hold or store the fruit. On certain rootstocks,
notably the rough lemon and Indian or Palestine sweet lime, the acidity
attained by most citrus fruits is significantly reduced as compared to
such common rootstocks as sour or sweet orange. As a
consequence, on these rootstocks maturity is advanced as judged by taste
or measured by the sugar-acid ratio. The flavor is not rich,
however, for the total soluble solids content of the juice is likewise
usually low. On certain other rootstocks, notably trifoliate
orange, the soluble solids are significantly increased, with the result
that although a corresponding sugar-acid ratio is attained at
approximately the same period the fruit has a richer
flavor. Earliness of commercial maturity, as measured by
either the sugar-acid ratio or acid content of the juice, may therefore
be markedly affected by the rootstock employed. Closely
associated with these effects is the ability of trees to hold or store
the fruit. The rough lemon as a rootstock causes the fruit to
lose quality—both juice content and flavor—and to drop earlier than
normal, whereas the bitter orange as a rootstock seems to prolong the
period of satisfactory storage on the trees.
The principal fruit characters
that may be affected by rootstocks include size, color, rind thickness,
juice content, and flavor. Thus, orange size is usually
somewhat larger on the trifoliate and bitter orange rootstocks and
smaller on sweet orange. Color is sometimes paler on the
rough lemon and Palestine sweet lime rootstocks and the thickness of
rind is generally greater, with a corresponding reduction in juice
content. And, as brought out above, flavor is richer on
certain rootstocks than on others. With the exception of
flavor, however, rootstock effects on fruit characters are usually less
marked than those caused by climatic factors.
Soil Influences.—That
the soil may affect tree characters and fruit characteristics is a
belief of long standing that finds support in observational
evidence. It appears that average fruit size is larger and
maturity is slightly earlier on the lighter-textured soils, but that the
color is likely to be paler, the rind thicker, and the flavor
poorer. And it is generally agreed that the fruit holds on
the trees better on the finer-textured soils.
Soil differences are usually small, however, unless accentuated by
rootstock effects. Thus, the undesirable influences of the
rough lemon rootstock are increased by sandy soils and reduced slightly
by silty soils.
Limitations of Descriptive Pomology.—From
the foregoing, it is clear that the horticultural characters concerned
in the identification and description of citrus fruit varieties are so
variable and subject to such profound environmental modification that
the problems presented are difficult indeed. Thus, on the
basis of fruit characters alone it is impossible to identify many
varieties. And it is difficult or impossible to accurately
identify numerous varieties on the basis of both tree and fruit
characters. It is highly probable that there are far fewer
varieties than the lists available indicate. This is further
suggested by the absence of comprehensive and dependable varietal keys
for countries and regions where citriculture has been practiced longest
and where varieties are most numerous.
With regard to varietal description, even though the sampling provides
representative materials, it is obvious that detailed and exact
descriptions are accurate and meaningful only for a given environment or
similar conditions of climate and rootstock. Thus,
descriptions of the same varieties in different countries or states
often fail to correspond in important respects. Perhaps the
best illustration is afforded by the differences between Florida and
California varieties. Detailed descriptions of Florida
varieties grown in California are far from accurate for Florida
conditions, and vice versa.
VARIETAL DEFINITIONS AND MODES OF ORIGIN
Irrespective of mode of origin and method of reproduction or
multiplication, a horticultural variety (cultivar) consists of a named
or otherwise designated group of plants representing one of the many
genetically different kinds of any given cultivated plant species or
botanical variety (Frost, 1943, p. 837). In citrus, as with
most other fruits, a horticultural variety traces back to a single
parent tree or individual mutant branch which has been multiplied by
vegetative or asexual means, such as cuttage or graftage. To
provide a more precise name for a group of such plants, Webber (1903)
introduced the term clone. Citrus varieties or cultivars are
therefore clonal varieties.
Complicating the situation to some degree is the fact that in most
citrus varieties the existence of the phenomenon of polyembryony makes
available apomictic seedlings of nucellar origin. These are
genetically identical with the seed parent, but may exhibit
physiological differences of some magnitude and duration that apparently
relate to age from seed propagation and diminish with time until they
ultimately disappear. These probably should be regarded as
juvenile characters. Because of these differences, it has
become desirable to distinguish between the parent, original, or
"mother" clonal selection or budline and the nucellar or "daughter"
clonal line of the same variety. For various reasons, in
California and increasingly so elsewhere in the United States, nucellar
or young clonal budlines or selections are rapidly displacing parent or
old clonal budlines, and this trend seems certain to extend to other
countries.
Another complicating factor
is the existence within certain varieties, notably among lemons in
California, of slight but consistent variations that can be detected
with certainty only by growing considerable numbers of trees of
different progenies in close proximity. These differences are
evident mainly in comparative habit of growth, vigor, density of
foliage, and sometimes in fruitfulness. Presumably, such
variations have arisen as seedlings or undetected budsports, principally
the latter, and have unintentionally been propagated. Since
the differences are small and detectable with difficulty, they have
commonly been referred to as strains. While this type
of delineation is well established in California, and to some extent
elsewhere, and may appear to have certain advantages, it is technically
incorrect according to the International Code of Nomenclature for Cultivated Plants (Anonymous,
1961, p. 13). So-called strains which exhibit desirable
characteristics and are considered worthy of distribution therefore
should be given varietal designations irrespective of origin or degree
of resemblance to already named varieties.
The selection and naming of outstanding old bearing trees as sources of
propagation materials is currently widespread in California and to some
extent elsewhere, having been greatly stimulated by the extensive
studies initiated about 1909 by Shamel (1943) and his
associates. Unfortunately, these old bearing selections have
commonly been incorrectly referred to as strains instead of
clonal selections or budlines. Almost without exception they
have been found to be identical with the variety in
question. Whatever differences in behavior they may have
exhibited, if any, are attributable to the nature and degree of virus or other
infections they carry. There have been a few such
selections, however, that apparently are different and represent
undetected bud variations in the parent tree or an error in its bud
parentage. These are in reality new or different clonal
varieties.
In common with other
fruits, citrus varieties may originate as chance seedlings, budsports
(somatic mutations), or hybrids resulting from plant
breeding. Most of the varieties currently grown doubtless
originated as chance seedlings. This is known to be true for
most of the orange and grapefruit varieties discovered in
Florida. This mode of origin is no longer operative to an
important degree, however. Some varieties are known to have
originated as limb sports, notably numerous navel orange and satsuma
mandarin varieties and the pigmented grapefruit varieties. A
few promising varieties resulting from breeding programs in Florida and
California have been introduced and others are in prospect.
The early literature (Han Yen-chih [1178], 1923; Ferrari, 1646; and
Bauhin, 1650) does not indicate specific recognition of the
horticultural variety concept, although it is suggested by descriptions
of numerous kinds of oranges, mandarins, lemons, and citrons, and
references to the budding and grafting of seedling trees. By
the nineteenth century, however, there can be little doubt that the
concept was recognized, since Gallesio (1811) described accurately eight
kinds of orange and Risso and Poiteau (1818-22) described and figured
forty-two varieties of citrus fruits.
The first relatively adequate horticultural classification of the citrus
fruits and description of their varieties in the United States is that
of Hume (1904, 1926) and the most recent and comprehensive that of
Webber (1943). In California, Spalding (1885) was perhaps the
first to attempt the listing and description of varieties, followed
shortly by Lelong (1888), who presented much more detailed and accurate
characterizations. For descriptions of Mediterranean
varieties, the reader is referred to Casella (1935a), Rebour (1950), and Gonzalez-Sicilia (1963).
THE PRINCIPAL VARIETIES AND THEIR MOST DISTINCTIVE CHARACTERISTICS
Because of the remarkable potency of environmental influences
on citrus fruit characters, detailed varietal descriptions will not be
attempted. Instead, the objective is to present the most
distinctive characteristics that will be helpful in identification and
evaluation. Insofar as practicable, this is done for all
varieties currently of commercial importance or likely to become
important. Less detailed treatment is given to varieties of
declining or limited local importance. Lack of information
requires that for many such the characterizations be sketchy and
incomplete.
The sources of information
used include the personal knowledge of the author based on observation
and study of the principal collections in the United States and
considerable travel abroad, the literature of the past four decades, and
personal communications from horticulturists in many parts of the
citricultural world.
The horticultural classification
employed in the sections that follow is that of the author and is
outlined at the beginning of the chapter. Obviously, it is
both arbitrary and empirical in considerable degree and hence subject to
valid differences of opinion. Since the classification is
based primarily on resemblance, it has seemed best to place the known
and presumed hybrid varieties in those groups they most resemble,
irrespective of parentage, known or presumed. In some cases,
resemblances are so tenuous that classification is difficult and
provisional, and in others lack of information may prove responsible for
errors.
For the most part, the
botanical nomenclature used is that of Tanaka (1954), whose system
though excessively detailed is much more comprehensive than the rigidly
restricted classification of Swingle (1943) and hence, in the opinion of
the writer, more useful. However, the use of Tanaka's
binomials is primarily for the convenience of the reader and should not
be interpreted as an unqualified acceptance or endorsement of his
classification in toto. Indeed; on the basis of the
natural groups and horticultural varieties with which the writer is
personally acquainted he cannot accept a number of the species in
question. Moreover, he frankly disclaims competence to pass
judgment on many others. It is his general conclusion,
however, that these two classification systems represent extremes and
that somewhere between them there will ultimately emerge a more
supportable and generally acceptable system of botanical classification
and nomenclature.
With the exception
of those varieties whose origin is unknown, such as the Valencia orange,
or which are widespread under names given elsewhere than in their
country of origin, such as the Washington navel orange, the names used
are those employed in the respective countries of origin or their
English equivalents. The principal synonyms are given in
parentheses. Insofar as practicable, the varieties described
in the following sections are presented in two groups for each fruit:
major and minor. Major varieties are those currently of
principal economic importance or which because of their promise seem
likely to become so. Minor varieties are those currently of
comparatively little importance or primarily of historical or other
interest. Within each group, the varieties are listed in
alphabetical order.
THE SWEET ORANGE (CITRUS SINENSIS [L.] OSBECK)
In common with most of the other citrus fruits of commercial
importance, the sweet orange appears to be native to the region
comprised by northeastern India and adjoining portions of China and
Burma. It appears to have been first grown commercially in
southern China. Its cultivation in the upper Mediterranean
basin has generally been considered to date back to approximately the
middle of the fifteenth century; not long thereafter it reached the
Western Hemisphere. However, Tolkowsky (1938) has adduced
evidence of a much earlier European introduction (200-300
A.D.). The sweet orange is the naranja of Spain, arancio of Italy, laranja of Portugal, orange of France and English-speaking countries, the malta of India, and kan of Japan.
The sweet orange is dominant in the citricultural world, since, with
the exception of the Orient where the mandarin is preferred, no other
citrus fruit is so universally liked and used. It is much
more widely distributed and grown than any other and currently comprises
about two-thirds of the total world production of citrus fruits, which
in 1965 was almost 600 million 70-pound box equivalents, and is
increasing rapidly. The United States was much the largest
producer of oranges with approximately 121 million boxes followed by
Spain (55 million), Brazil and Italy (24 and 37 million, respectively),
Mexico and Argentina (24 and 20 million, respectively), Israel (23
million), and Morocco and South Africa (16 and 15 million,
respectively). Six other widely-distributed countries produce
5 million to 10 million boxes annually and eleven others a million
boxes or more. The remaining citrus fruits are produced by
about two dozen other widely distributed countries. Moreover,
both planting and production will certainly increase during the coming
decades. As this chapter went to press in 1967, the Florida
orange crop alone was estimated at 143 million boxes.
With the exception of the mandarin and bitter or sour orange, the sweet
orange tree is the hardiest of the citrus fruits of commercial
importance. The mandarin fruit is much more susceptible to
frost injury, however.
In most parts
of the world, the sweet orange is still used primarily as a fresh fruit
for eating out-of-hand or serving as a dessert. In the United
States, however, and increasingly so elsewhere, the principal use now
is for the juice, which is extracted and served fresh or preserved by
chilling, pasteurization, and concentration (see chap. 2, p. 47 [text
version, Revised Ed.]). The single-strength canned juice now
available is a reasonably satisfactory substitute for freshly expressed
juice and keeps relatively well. Much the best product,
however, in that it is acceptable as a substitute to all but the most
discriminating palates, is the frozen juice concentrated under vacuum,
which of course, requires freezing storage. The consumer
acceptance of this product has been phenomenal, and much the greater
part of the Florida production is now utilized in this
form. The use of oranges for juicing, enhanced by the
spectacular success of frozen concentrate, has materially increased the
consumption of oranges in the United States and brought about greatly
increased production in Florida.
Valuable byproducts are also obtained from the rind of fruit sent to
processing plants for juicing. Principal byproducts are
essential oil, pectin, and cattlefeed.
The sweet oranges naturally fall into four kinds: the common oranges,
acidless oranges, pigmented oranges, and navel oranges. They
may also be distinguished on the basis of season of maturity as early,
midseason, and late. In some of these groups, possibly all,
there are variegated varieties of local importance as ornamentals, such
as the dwarf variety Fuya Menuda.
These comprise the ordinary or common oranges which in the
Mediterranean basin are referred to as the white or blond orange (blanca of Spain, biondo of Italy, blonde of
France) to distinguish them from the pigmented or blood
orange. The characteristics of the common oranges are so well
known as scarcely to require comment. Indeed, the
distinctive color—a combination of red and yellow—has for centuries been
used as the common name of this fruit, in which connection it may be of
interest to note that yellow-fruited orange varieties have long been
known (such as the Prata of Spain and Tenerife of the Canary Islands).
In most of the older orange-producing countries, there still remains a
considerable production of sweet oranges from seedling clones grown
either as seedlings or budded trees. In Spain and Italy,
these are usually referred to as comuna or comune (Biondo
di Spina or di Arrudi), respectively, and in Florida as Florida
Common. In North Africa and the Near East, they are called beladi or beledi (various spellings), bizri (when grown as seedlings), and Bordugal (Portugal). They are known as criolla in Argentina and Uruguay, caipira in Brazil, and corriente in
Mexico. And finally, in South Africa and Australia, they are
called Cape Seedlings and Paramatta Seedlings, respectively.
In general, the seedling clone trees are vigorous, large, somewhat
thorny, productive, and long-lived, but the fruit is commonly coarser in
texture and seedier than most named varieties. With minor
exceptions, the propagation and planting of these seedling clones has
been abandoned in favor of better, named varieties. It must
be remarked, however, that under certain conditions these seedling
clones are sometimes more profitable than the named varieties available
and hence will continue to be used. So long as they remain
profitable, there is little incentive for growers to replace such
orchards.
As might be expected, the
common sweet oranges are the most widely grown and commercially the most
important of the four kinds of sweet oranges. There is
reason to believe that they constitute about two-thirds of total orange
production.
They are not only the
oldest, largest, and most extensively cultivated kind of sweet oranges,
but they include more varieties than any other.
Major Common Orange Varieties.—Descriptions
are presented below of those common orange varieties grown on an
extensive scale, increasing in importance, or which the author believes
have qualities of major significance.
Barão
Fruit medium-small, ovoid to oblong; base with occasional radial
furrows; seeds comparatively few. Rind medium-thick and
surface smooth. Color deep orange when ripe. Flesh
well-colored; coarse, firm in texture; juice content below average;
flavor rich and sweet. Medium early in maturity.
Tree vigorous, upright, medium-large; foliage dense; very productive.
This Brazilian variety (Moreira and Filha, 1963) is of unknown origin,
presumably a chance seedling, and does not meet the requirements of the
processing industry or export trade. It is said to be much
appreciated by the Brazilian populace.
Bedmar
See under Berna.
Belladonna
Fruit medium-large, oblong to oval; base commonly with small, slightly
furrowed basin; areole faint or lacking; seeds few or
none. Color deep orange at maturity. Rind
medium-thick, tightly adherent as are also the segments; surface finely
to coarsely pebbled. Flesh moderately juicy and flavor
pleasant. Early midseason in maturity, but holds well on tree
for several months. Stores and ships well.
Tree vigorous, medium to large, symmetrical, and productive.
An old Italian variety of unknown origin, Belladonna is widely grown in
Italy and ranks second there only to Calabrese.
According to Casella (1935a),
the fruits of Belladonna and Calabrese have close resemblances, but the
former averages larger, is better colored, and has a thicker and
somewhat coarser rind. The season is altogether different as
are also the trees. Both varieties are of excellent quality.
Berna (Bernia, Verna, Vernia, Verda, Bedmar) (fig. 4-3)
Fruit medium-small, oval to ellipsoid; base commonly with faint radial
furrows; apex slightly depressed; seeds few or
none. Well-colored at full maturity, but regreens
thereafter. Rind medium-thick, firm; surface finely
pebbled. Flesh well-colored; moderately juicy; flavor
sweet. Fruit holds especially well on tree with good quality
and ships well. Late in maturity, but earlier than Calabrese
of Italy and Valencia.
Tree
slow-growing, compact, medium-small in size, and slow to bear but
productive. Somewhat inclined to out-of-season flowering and
production of worthless off-season fruits. Usually has a few
long and narrow leaves.
This
distinctive variety is of Spanish origin but is grown also in Morocco
and Algeria. It is one of the latest maturing of all
Mediterranean varieties and holds on the trees as well as Valencia or
better but is smaller and of poorer quality.
Several clones of the Berna are recognized, one of which is
characterized by greater tree vigor and round fruit of higher juice
content. A selection named Alberola is said to be of superior
quality. A highly similar, if not identical, variety is
Peret.
Biondo Comune (Nostrale Liscio)
Fruit medium to medium-large, subglobose to round; basal cavity small
and deeply furrowed; apex flattened or slightly depressed;
seedy. Color yellowish-orange at maturity. Rind
medium-thick and surface finely to moderately pebbled. Flesh
very juicy and flavor pleasant when fully mature. Medium
early in maturity, but holds well on tree and ships well.
Tree vigorous, hardy, large, and productive.
One of the oldest Italian varieties and of unknown origin, Biondo
Comune has been little planted in recent decades and doubtless will
ultimately disappear. It still comprises the bulk of
production of common sweet oranges in some of the oldest Italian
districts.
Biondo Riccio
Fruit large, globose; base slightly flattened and deeply furrowed; apex
slightly depressed; seedy. Well-colored at
maturity. Rind medium-thick and surface coarsely pebbled and
somewhat rough. Flesh juicy and flavor pleasant when fully
ripe. Medium early in maturity and ships reasonably well.
Tree moderately vigorous, highly productive, and hardy.
Another very old Italian variety of unknown origin, Bionao Riccio has
not been planted for years but is still important in some of the oldest
Italian districts.
Biondo di Spina
See under common oranges.
Cadenera (Cadena Fina, Cadena sin Jueso, Orero, Valence san Pepins, Precoce de Valence, Precoce des Canaries) (fig. 4-4)
Fruit medium-sized, globose to slightly oval; apex somewhat depressed;
areole ring faint or lacking; seeds few or none. Moderately
well-colored. Rind medium-thin and surface smooth to finely
pebbled. Flesh very juicy and flavor and aroma
excellent. Holds well on tree and retains
quality. Medium-early in maturity (preceded by Salustiana and
Hamlin).
Tree vigorous, hardy, large, and productive.
Of Spanish origin, presumably a chance seedling, Cadenera appears to be
the most important variety in Spain, its production being exceeded only
by only by comuna, which, as noted earlier, consists of a group
of unnamed similar or identical seedling clones. It is
important also in Morocco and Algeria and hence ranks high among major
orange varieties. Because of its excellent quality, it is
well and favorably known in European markets.
Cornice appears to be a selection of Cadenera (Chapot, 1948) but Cadena
Punchosa is an inferior variety no longer being planted.
Calabrese (Ovale) (fig. 4-5)
Fruit medium-large, oval; base commonly with low, narrow, slightly
furrowed collar; areole faint or lacking; seeds few or
none. Well-colored at maturity, but regreens if held on the
tree long thereafter. Rind medium-thick, very tightly
adherent; surface finely pebbled. Flesh juicy and well
flavored at maturity. Holds especially well on tree with
little loss in quality and stores and ships well. Late in
maturity (the latest of Italian varieties and approaching Valencia).
Tree of good vigor and size, slow growing, somewhat irregular in form;
leaves light-green and of somewhat distinctive color and
appearance. Pronounced tendency to produce out-of-season
bloom and fruit. Sensitive to cold, heat, and desert winds,
but productive under favorable conditions.
Calabrese is the preferred name to distinguish this important variety from others of oval form.
Of unknown origin, this old Italian variety is widely grown and for
decades has ranked as first in importance among common sweet orange
varieties in Italy, a position it seems destined to maintain because of
its many excellent features.
California Mediterranean Sweet
See under Maltaise Oval.
Castellana
Fruit medium-sized, subglobose to spherical; moderately
seedy. Color light orange. Rind medium-thin and
surface somewhat granular. Flesh color pale; juice abundant,
low in acidity; flavor sweet. Holds on tree moderately well
but loses quality. Medium early in maturity.
Castellana is said to be the principal variety in the Almería Province
of Spain where it matures earlier than elsewhere. It is no
longer being planted, however.
Clanor (Clanwilliam, Clan William)
Fruit medium-large, globose to oblong; seeds relatively
few. Rind medium-thin, tough, leathery; surface moderately
pebbled. Flesh melting, juicy; flavor good. Late
midseason in maturity.
Tree vigorous, upright in growth habit; foliage dense; a regular and heavy bearer.
This South African variety from western Cape Province traces back to
two apparently identical trees in the 30-year-old William van Wyk
orchard of the Kanolvlei farm that had been layered from old Clanwilliam
seedling orange trees on the Rondegat farm. The selection
was made by P. Nortier of Clanwilliam in
1930. Clanor has gained rapidly in popularity and currently
is recommended as one of the best midseason varieties for planting in
South Africa.
Clanwilliam
See under Clanor above.
Garey's Mediterranean Sweet
See under Pope.
Glen Summer
See under Pope.
Hamlin (Norris) (fig. 4-6).
Fruit medium-small, globose to slightly oblate; sometimes with low
radially furrowed collar and faint areolar ring; seeds very few or
none. Well-colored at maturity (one of the best in
Florida). Rind thin, with smooth, finely pitted
surface. Flesh well-colored; tender, juicy, lacking in acid;
flavor sweet. One of the earliest to mature.
Tree moderately vigorous, medium-large, productive, and more cold-tolerant than most.
The Hamlin variety originated as a chance seedling in an orchard near
Glenwood, Florida, which was planted in 1879, and was named for the
owner, A. G. Hamlin, at the time its value was recognized some years
later. It came into prominence following the great Florida
freeze of 1894-95 as a rival of Parson, the only other variety of
similar early maturity, and has gradually replaced
it. Currently, it is a major variety in Florida, of
considerable importance as an export variety in Brazil, of limited
importance in South Africa and elsewhere, and possibly the world's
principal variety of very early maturing common sweet orange.
In semitropical climates characterized by high heat and humidity, this
variety produces fruit of satisfactory size for marketing fresh,
although the eating quality is generally somewhat
disappointing. In arid, subtropical climates, fruit size is
commonly smaller than desirable though the quality may be satisfactory.
Hart's Tardiff
See under Valencia.
Hitmali
See under Khettmali.
Homosassa
Fruit medium-sized, subglobose to ellipsoid; base evenly rounded to
slightly collared and basal area somewhat furrowed; apex evenly rounded;
areolar furrow indistinct or lacking; moderately
seedy. Well-colored at maturity. Rind
medium-thick, smooth, and finely pitted. Flesh medium-tender,
juicy; flavor good. Midseason in maturity.
Tree vigorous, large, productive, and hardy.
According to Webber (1943), Homosassa is one
of the oldest Florida varieties, having originated as a seedling
selection in the orchard of a Mr. Yulee at Homosassa. The
selection must have been planted not later than 1865, for in 1877 the
Variety Committee of the American Pomological Society recommended it as a
first-class variety. It was extensively planted for some
decades, and there are old orchards still in existence. Like
certain other Florida varieties, however, Homosassa is of indifferent
quality in arid climates and has not achieved commercial importance
elsewhere.
Jaffa (Florida Jaffa)
Fruit medium-sized, globose to slightly ellipsoid or obovate; basal end
commonly collared and with radial furrows; areole inconspicuous or
absent; seeds comparatively few. Well-colored under favorable
conditions. Rind medium-thick, finely pitted, and moderately
pebbled. Flesh color light orange; medium-tender, juicy;
flavor good. Stores poorly on tree, but ships rather
well. Midseason in maturity.
Tree vigorous, upright, medium-large; foliage dense; cold-resistant;
moderately productive, but with alternate bearing tendency.
In the literature and otherwise, this variety has sometimes been
confused with Shamouti or Palestine Jaffa, the principal variety of
Palestine and Israel, which it resembles only slightly. On
the other hand, it somewhat resembles Joppa. Almost certainly
both Jaffa and Joppa are clones of the Palestine beledi seeding
group. Jaffa was introduced into Florida by H. S. Sanford
about 1883, whether as budwood or seeds is not known, but presumably the
latter. Joppa was named about 1877 in California as a
seedling from seeds obtained in Joppa, Palestine. In this
general connection, it is of interest to note that Shamouti is
considered to have originated as a limb sport in a Palestinian beledi tree.
Because of its comparatively low seed content, cold resistance, and
good quality, Jaffa early became popular in Florida and attained the
status of a major midseason variety. The greater productivity
and superior quality of Pineapple, however, soon caused it to lose
favor, although Jaffa still remains important there and to some extent
elsewhere. For processing, however, Jaffa's susceptibility to
Alternaria blossom-end infection is a further cause for its decline in
popularity in Florida.
Joppa
Fruit medium-sized, globose to slightly oblong; seeds comparatively
few. Well-colored under favorable conditions. Rind
medium-thin and slightly pebbled. Flesh color light orange;
medium-tender, juicy; flavor rich. Midseason in maturity.
Tree vigorous, upright, with rather stiff thornless branches and stout
branchlets; precocious, and prolific.
This variety, not to be confused with the Jaffa above, originated in
1877 from seed imported from Joppa, Palestine, by A. B. Chapman of San
Gabriel, California. It never attained commercial importance
in California or in Florida, where it was early introduced, but it was
popular for some decades in South Africa and still has limited
importance in Texas.
In comparison
with Jaffa, the fruit averages smaller and is less oblong, the rind
texture is finer, and the season of maturity is earlier. The
tree is more upright, has thicker branchlets, and is more
precocious. In general appearance, Joppa resembles Shamouti
more than Jaffa. In South Africa, it is reported (Marloth and
Basson, 1955) that on rough lemon rootstock Jaffa and its seedlings
exhibit budunion "crease" whereas Joppa and its derivatives do
not. Addorosa is a local synonym in South
Africa. The Fukuhara variety of Japan is considered to be a
bud variation of Joppa.
Khalily White
See under Shamouti Masry.
Khettmali (Khatmali, Hitmali)
Fruit medium-large, round to somewhat oblong; areolar ridge usually
well-developed (from which the name is derived); seeds very
few. Well-colored at maturity. Rind medium-thin,
tough, leathery; surface moderately pebbled; peels
readily. Flesh moderately firm, very juicy; flavor
excellent. Holds well on tree. Midseason in
maturity, but later than Shamouti.
Tree vigorous and consistently productive.
This variety appears to have originated in Lebanon, where it is highly
regarded and second only in importance to Shamouti. From the
description, it is clear that Hitmali of Israel and Khettmali are
identical.
Macetera
Fruit medium-sized, subglobose to globose; apex slightly depressed;
seeds few. Rind very thin, smooth, and finely
pebbled. Color pale. Flesh tender, juicy, and with
special flavor and fragrance. Fruit holds well on tree, but
sensitive to frost. Midseason in maturity.
Tree robust, large-sized, and somewhat thorny. A regular and good bearer.
This high-quality, old Spanish variety is said to be increasing in
importance, especially in Alicante Province, but its thin rind and
juiciness make it a poor shipper and keeper. It is considered
excellent for processing.
Malta (Malta Common)
Malta is a seedy, midseason orange of good color and flavor, but
without distinctive characteristics, which is widely grown in the Punjab
region of India and West Pakistan. The trees are vigorous
and productive.
It is similar to and indistinguishable from beladi of the Near East and North Africa and comuna of Spain and Italy and doubtless was introduced from the Mediterranean.
Maltaise Blonde (Maltaise, Petite Jaffa, Portugaise Blonde)
Fruit medium-large, oval; seeds very few or none. Moderately
well-colored at maturity. Rind medium-thick, leathery;
surface smooth and finely pebbled; peels easily. Flesh
moderately well-colored; juicy; flavor mild. Does not hold
well on tree, but if properly handled stores and ships
well. Midseason in maturity.
Tree vigorous and characterized by open growth habit, thick branchlets,
and large, broad leaves. Low in productivity.
Both the tree and fruit resemble Shamouti (Palestine Jaffa) and it is
evident that they are closely related. Markedly similar also
is Shamouti Masry (Khalily White) of Egypt, which is believed to have
originated as a limb sport of Shamouti.
The Maltaise Blonde variety, of unknown origin, is of limited
importance in North Africa except in Tunisia, where it is popular and
grown commercially.
Maltaise Ovale (Maltese Oval, Garey's or California Mediterranean Sweet)
Fruit medium-sized, spherical to oval; basal collar radially furrowed;
seeds relatively few. Color pale at maturity and some
tendency to regreen. Rind medium-thick; surface somewhat
pebbled; peels readily. Flesh pale-colored; moderately juicy;
flavor mild. Medium-late in maturity.
Tree vigorous, large, spreading, and drooping; leaves long, narrow,
somewhat rumpled, and of paler color than most. Distinctive
in appearance.
This is an old
Mediterranean variety of unknown origin which was introduced into
California about 1870 by T. A. Garey, a pioneer citrus nurseryman of Los
Angeles, and distributed under the name Mediterranean
Sweet. At about the same time, it was brought to Florida and
distributed under the name Maltese Oval. It is not the same,
however, as the midseason variety introduced into Florida a few years
later and distributed as Mediterranean Sweet.
Under its California name, this variety soon became important as a
midseason variety, maturing between the superior Washington navel and
Valencia oranges. With the expansion of the California
industry into areas of different periods of maturity, overlapping
production of these two varieties resulted. As a consequence,
Mediterranean Sweet rapidly lost favor and was replaced. In
the meantime, it was introduced into South Africa where it still retains
some importance as a midseason variety, although it is no longer
planted.
Two clones are recognized in
California which differ only in fruit form, one being prevailingly round
and the other oblong to oval.
Marrs (Marrs Early)
Fruit medium-large, round to slightly oblate; moderately seedy
(depending on pollination). Well-colored under favorable
conditions. Rind medium-thick, and surface smooth and finely
pitted. Flesh well-colored; juicy, lacking in acid; flavor
sweet. Holds well on tree with little loss in
quality. Earliest in legal maturity because of low acidity, but for better juice content and quality should be left on tree somewhat later.
Tree moderately vigorous, precocious, and prolific. Marked
tendency to bear fruit in clusters. Smaller than most other
varieties, presumably because of early and heavy bearing.
According to Waibel (1953), this variety was found in 1927 on the place
of O. F. Marrs, Donna, Texas, where it is said to have occurred as a
limb sport in a group of navel orange trees obtained from
California. Although propagated to a limited extent earlier,
trees were not available for commercial planting until 1940.
Because of its early and heavy bearing and good fruit size, Marrs is
currently a popular early maturing variety in Texas. Its
principal fault for processing is the low acidity of the juice.
Mediterranean Sweet
See under Maltaise Ovale.
Mosambi (Mosambique)
Fruit medium-large, slightly oblate to globose or broadly obovoid;
areolar ring regularly shallow; moderately seedy. Color light
yellow to pale orange at maturity. Rind medium-thick;
surface moderately to roughly pebbled, and faintly striped with narrow,
longitudinal grooves and ridges. Flesh color straw-yellow;
somewhat firm, juicy; flavor insipid because of very low
acidity. Early in maturity.
This very distinctive variety is of unknown origin, but the name, of
which there are numerous spellings, suggests that it was taken from
Mozambique, East Africa, to India, presumably by the
Portuguese. The brown color of the chalazal spot indicates
that it does not belong to the sugar orange group, as some have assumed,
but that it is a low acid orange, the acidity of which is further
reduced by the Indian climate and the rough lemon rootstock on which it
is grown.
Mosambi is highly popular in
central India and is probably the most important orange variety of that
country. According to Gandhi (1956), it is grown principally
in the Bombay Deccan where total plantings were reported to be about
20,000 acres.
Mosambique
See under Mosambi above.
Natal
Fruit medium-sized, globose to broadly obovoid; seeds very
few. Rind medium-thin and surface moderately
pebbled. Color pale yellowish-orange. Flesh
pale-colored; tender, fine-textured, very juicy; flavor rich at full
maturity because of high acidity. Shipping quality
good. Very late in maturity.
Tree vigorous, large, and productive.
Of unknown origin, this Brazilian variety is said to markedly resemble
Valencia in both fruit and tree characters.
Norris
See under Hamlin.
Nostrale Liscio
See under Biondo Comune.
Orero
See under Cadenera.
Parson (Parson Brown)
Fruit medium-large, globose; base with short, radial furrows; areole
indistinct; moderately seedy. Well-colored under favorable
conditions. Rind medium-thick; surface finely pitted and
moderately pebbled. Flesh color dull orange; firm, juicy;
well-flavored. Very early in maturity, possibly the earliest.
Tree vigorous, large, and productive.
Parson originated as a chance seedling in the dooryard of Rev. N. L.
Brown near Webster, Florida, and is said to have been planted in 1856
(Ziegler and Wolfe, 1961). The propagation rights were
purchased about 1875 by J. L. Carney, who named it Parson
Brown. Its outstanding earliness soon popularized this
variety and it quickly became the leading early orange, a position held
until about 1920. Parson still remains a major variety in
Florida, however, though it has never achieved prominence elsewhere,
principally because of seediness.
Pera (fig. 4-7)
Fruit medium-small, ovoid to ellipsoid; seeds very few. Rind
medium-thin; surface smooth and finely pitted. Color light
orange at maturity. Flesh well-colored; firm, fine textured,
juicy; flavor rich. Late in maturity. Holds well
on tree without deterioration in quality, and stores and ships well.
Tree vigorous, upright; foliage dense, with many leaves of which the
petioles are unevenly winged; very productive.
Moreira and Filha (1963) and other Brazilian horticulturists have
expressed the opinion that the Pera variety is probably the same as Lamb
Summer of Florida. If so, it originated as a seedling in
Volusia County sometime prior to 1897, when it was first described and
named for the owner. It never attained much importance in
Florida. Several clones are recognized of this variety in
Brazil, including Perão, a light-bearing tree with fruit which is large
and resembles Shamouti. A. A. Salibe has called attention to
the resemblance between Pera and the Berna variety of Spain.2
Introduced into Brazil at an early date, Pera has long been the
principal variety as well as the most important late export
variety. It constitutes nearly three-fourths of the
commercial acreage in the region of Rio de Janeiro and slightly more
than a third of the commercial acreage in São Paulo State.
Petite Jaffa
See under Maltaise Blonde.
Pineapple
Fruit medium-sized, spherical to slightly obovate; basal area sometimes
depressed and radially furrowed; commonly with faint areolar ring;
moderately seedy. Well-colored (one of the best in
Florida). Rind medium-thick; surface finely pitted and
slightly pebbled. Flesh color light orange; tender, juicy;
flavor rich though sweet. Midseason in
maturity. Does not hold on tree as well as some, but
excellent for processing.
Tree
moderately vigorous, medium-large, thornless, and highly
productive. More sensitive to frost than most.
The Pineapple originated as a seedling on the place of J. B. Owens at
Sparr, near Citra, Florida, and is said to have come from seed planted
soon after 1860 (Ziegler and Wolfe, 1961). It was first
propagated by P. P. Bishop at Citra about 1873 under the name of Hickory
and some ten years later was renamed Pineapple because of its delicate
fragrance. Its attractiveness, fine flavor, and good market
reception brought about some increase in use, but it was not until after
the 1894-95 freeze, which necessitated extensive replanting, that its
popularity developed. It soon became the principal midseason
variety and has remained so ever since. It is a major variety
in Florida and of considerable though decreasing importance in Brazil
and South Africa. Of increasing popularity in Florida is the
Queen variety, which may have originated as a Pineapple
seedling. Two virtually seedless limb sports have been
found—Seedless Pineapple, discovered in 1932 on Merritt Island, Florida
(U.S. Plant Patent 477), and more recently (1948) a variety named
Plaquemines, which originated as a limb sport in
Louisiana. Varieties that are considered to be derivatives in
South Africa include Belvedere, which is indistinguishable from
Pineapple, and Gem and Letaba, both of which are less seedy and earlier
in maturity. A seedling clone that exhibits resistance to the
burrowing nematode in Florida has recently been named Ridge Pineapple.
Pope (Pope Summer, Glen Summer)
Pope is a variety so similar to Valencia that they are
indistinguishable, and its origin suggests that it probably should be
regarded as a selection of Valencia rather than a
variety. According to Ziegler and Wolfe (1961), it traces
back to an outstanding budded tree that was found by F. W. Pope about
1916 in a 40-acre planting of the Pineapple variety near Lakeland,
Florida. It was so late in maturity and held the fruit so
well without loss in quality that Pope undertook its commercial
propagation in 1935 and had the name trademarked in
1938. Since 1945 its propagation and promotion have been
conducted by Pope Summer Orange Nursery, Ltd., though the same variety
is reported (Ziegler and Wolfe, 1961) to be propagated by the Glen St.
Mary Nurseries Company under the name Glen Summer. It has
been planted to a considerable extent in the Indian River district of
Florida.
Portugaise Blonde
See under Maltaise Blonde.
Precoce des Canaries
See under Cadenera.
Precoce de Valence
See under Cadenera.
Premier
Fruit medium-small, globose; seeds relatively few. Rind
medium-thick and surface moderately coarse. Flesh very juicy
and flavor good. Early midseason in maturity.
Tree moderately vigorous, of irregular, upright growth habit; medium-sized; very productive.
Of unknown parentage, Premier is a selection of the Joppa type
introduced about 1935 by the late Professor H. Clark Powell, of the
University of Pretoria, from the Mazoe Citrus Estates, Umtali, Southern
Rhodesia. Montrose Premier is indistinguishable and
apparently represents a clonal selection. The so-called
Orange Premier is an entirely unrelated clone of the Jaffa type that is
subject to the budunion crease disease and should be
discarded. Premier has proven to be popular and is currently
the most important midseason variety in the Lowveld areas of Transvaal,
South Africa. It also is grown extensively in Southern
Rhodesia.
Queen
The Queen was originally named King, but later the name was changed to
avoid confusion with the old King mandarin variety. This is a
midseason variety with fruit much like the Pineapple
orange. It is less pronounced reddish-orange in color, higher
in soluble solids and hence richer in flavor, somewhat less seedy, and
holds better on the tree.
The tree is
more vigorous than Pineapple, equally productive, and somewhat more
resistant to cold.
According to
Ziegler and Wolfe (1961), this variety originated as a seedling in an
old orchard on Lake Hancock, near Bartow, Florida, and came to notice
prior to 1900 at which time budwood was obtained by a Mr. Walters from a
Mr. King, a son-in-law of the owner. It was used to
propagate trees for the Perrin and Thompson Groves near Winter Haven,
the owners of which gave it the name King. Its
commercialization was undertaken by the Lake Garfield Nurseries of
Bartow about 1915 under the present name. For some decades it
did not receive much attention, but its popularity has increased
appreciably in recent years.
Salustiana (Salus) (fig. 4-8)
Fruit medium-large, subglobose to spherical; basal cavity shallow with
faint radial furrows; apex depressed; areolar ring small but well-marked
in many cases; virtually seedless. Unusually well-colored at
maturity. Rind medium-thick and surface moderately
pebbled. Flesh melting, juicy; flavor rich and
sweet. Fruit said to hold especially well on tree without
much loss of quality. Early in maturity (earliest of the
Spanish varieties).
Tree vigorous, somewhat upright, medium-large, and productive.
This comparatively new Spanish variety is believed to have originated as a limb sport on a comuna tree
in the garden of a convent. It was called to the attention
of Don Salustiano Pallas of nearby Enova, Valencia, and propagated and
introduced by him about 1950 (Gonzalez-Sicilia,
1963). Because of its early maturity, seedlessness, and
quality, it is regarded as highly promising and has been planted to a
considerable extent in Spain in recent years and somewhat in Algeria and
Morocco.
According to Chapot and Huet
(1963), who have reported on the characteristics of this variety in
North Africa, both tree and fruit are indistinguishable from Cadenera,
except that the latter is somewhat flatter in
form. Salustiana is much earlier in maturity, however.
Sathgudi
Fruit medium to large, globose; moderately seedy. Color
greenish-yellow to pale orange at maturity. Rind
medium-thick, tough, leathery; surface finely pitted and moderately
pebbled; peels readily. Carpellary membranes thick and tough;
flesh orange-colored; juicy; flavor fair (sweet with some
acid). Midseason in maturity insofar as can be determined.
Tree vigorous and moderately productive. Commonly seed-propagated.
The origin of Sathgudi is unknown, but probably relates to a village or
community. However, one of its local names in southeast
India suggests that it may have come from Batavia,
Indonesia. For many years it has been the principal variety
in southern India.
Seleta (Selecta, Siletta)
Fruit medium-sized, subglobose to spherical; basal area sometimes with
radiating furrows; apex rounded or slightly flattened; areole usually
distinct; seeds few. Rind medium-thick; surface smooth to
slightly pebbled; color light orange. Tendency to color in
advance of maturity, while still acid. Flesh juicy; flavor
somewhat acid until full maturity, when it becomes sprightly and readily
acceptable. Fruit does not hold well on tree after maturity,
dropping freely. Late midseason in maturity though coloring
early.
Tree moderately vigorous,
medium-sized, and regularly productive. A tendency to give
rise to bud variations has been noted in California (Webber, 1943, p. 516) and Australia.3
The origin of Seleta is unknown, but it seems likely that it is an old
Portuguese variety, for in 1925 it was listed among those currently
grown there (Bobone, 1938) and the synonym employed, Lusitana, referred
to the ancient Roman provincial name for Portugal. Presumably
taken to Brazil at an early date, it is the variety from which the
Bahia or Washington navel orange is supposed to have originated
(Dorsett, Shamel, and Popenoe, 1917), although to the writer this seems
improbable. According to Moreira and Filha (1963), it is
still of commercial importance in Brazil, where several clonal
selections are currently popular—Abacaxi, Amarela, Branca, Itaborai, and
Vermelha. It seems likely that this variety is the Siletta
of Australia as the Sydney Gazette of April 22, 1824 (Bowman,
1955) lists Celeta and Bahia oranges among recently introduced citrus
varieties. It early achieved commercial importance in
Australia, which continued until about 1920. Since that time
it has been infrequently planted and only for juice purposes.
Two clones have long been recognized in Australia—White Siletta, which
corresponds to the description given here, and Red Siletta, so-named
because of its deeper color. The Red Siletta is presumably of
local though unknown origin. The first-mentioned clone is
that which achieved principal importance. The fruit of the
latter is coarser in rind texture and somewhat lower in quality; the
tree is more vigorous and larger.
Shamouti (Chamouti, Palestine Jaffa, Jaffa, Jaffaoui, Iaffaoui). (fig. 4-9)
Fruit medium-large to large, oval to ellipsoid; basal end slightly
flattened or depressed with narrow and low collar or shoulder, commonly
with short radial furrows; apical end evenly rounded; areolar ring
usually present but faint. Seedless or nearly so and
well-colored under favorable conditions. Rind thick, tough,
and leathery; surface finely pitted but relatively smooth; inconspicuous
oil glands. Flesh color light orange; firm, tender, juicy;
fragrant and pleasantly sweet-flavored. Fruit peels and
segments separate readily. Ships and stores unusually well,
but does not process well. Midseason in maturity.
Tree moderately vigorous, distinctive in appearance, upright in growth
habit, with thick, thornless branchlets; leaves large and broad, with
petioles which are small and narrowly winged. On Palestine sweet lime rootstock, tree is somewhat dwarfed, probably because of xyloporosis infection, but is regular and highly productive, whereas tree is larger on sour orange but less productive because of pronounced alternation.
While Shamouti, of which there are various other spellings, is the
preferred name for this distinctive and highly important variety, it is
so well and favorably known in Europe under the name Jaffa that it is
now impracticable, as well as undesirable, to undertake to change this
usage. There is another, quite different variety of the same
name and parentage, however, frequently called Florida Jaffa to
distinguish between them (see Jaffa).
Like the navel oranges in general, the Shamouti tree is sensitive to
heat and aridity during the bloom and hence restricted in range of
climatic adaptation. Thus, in very hot, arid regions
production is low and the fruits are undesirably large and
coarse. Shamouti is clearly not adapted to hot desert or
semitropical climates. For reasons that are not clear,
probably relating to both climate and rootstock, the commercial culture
of this variety is restricted to climatically favored portions of the
eastern end of the Mediterranean basin.
According to Oppenheim (1927, 1929), Shamouti originated some time
prior to 1844 in an orchard near Jaffa, Palestine (now Israel),
presumably as a limb sport in a tree of the local or beledi variety (see also under Jaffa). Its
qualities were so outstanding that within a few decades it became the
leading variety in Palestine and has maintained this position ever
since. It spread to nearby countries and attained importance,
notably in Lebanon, Turkey, and Cyprus. It was early
exported to Europe, principally England, where it soon established a
reputation for its size, quality, and seedlessness. Its
distinctive shape provided a natural trademark. Currently,
Shamouti is by far the principal variety of the Near East and one of the
major varieties of the world. In addition to the countries
already mentioned, it is the leading variety in Syria and is grown to
some extent in Greece and Egypt. The 1965 production of this
variety was estimated at not less than 20 million boxes.
Although efforts were made early to establish this highly reputed
variety in both California and Florida, the seed introduced apparently
came from fruits of the seedy parent variety rather than the almost
seedless Shamouti and gave rise to the Florida Jaffa and Joppa varieties
(see Jaffa and Joppa). This
fact was not realized for many years, and it was not until about 1920
that the true Palestine Jaffa (Shamouti) was introduced. Thus
far, it has not compared favorably in quality and productivity with
other varieties.
The evidence
indicates that the Shamouti clone is highly unstable and prone to the
occurrence of limb sports. Thus, Oppenheim (1927, 1929) and
Chapot (1964c) report numerous instances of Shamouti trees containing branches that produce round, seedy fruits typical of beledi, and a few cases have been reported of beledi trees with Shamouti-like limb sports. Chapot (1954, 1955b)
reports the existence of four varieties in Lebanon, the names of which
clearly suggest the likelihood of Shamouti origin. They are
Shamouti or Iaffaoui Beledi, a seedy Shamouti; Shamouti or Iaffaoui
Maouardi, a seedless blood Shamouti; Maouardi Beledi, a seedy, blood
Shamouti; and Shamouti or Iaffaoui Moghrabi or Meski, an acidless, seedy
Shamouti. Other varieties which markedly resemble Shamouti
and are known to have originated from it include Kinariti or Kinnereth
(Early Shamouti) and the pink-fleshed Sarah of Israel and Shamouti Masry
(Egyptian Shamouti or Khalily White). (See Shamouti Masry,
below.) Finally, it should be noted that Maltaise Blonde of North
Africa, sometimes called Petite Jaffa, and Barile of Italy closely
resemble Shamouti though their fruit is somewhat smaller (see Maltaise Blonde).
Shamouti Masry (Khalily White, Egyptian Shamouti)
Fruit medium-large, ellipsoid to oval; seeds few or
none. Color orange to deep orange. Rind
medium-thick; surface finely pitted and relatively smooth; peels
readily. Flesh well-colored; juicy; flavor rich and
sweet. Midseason in maturity. Indistinguishable
from Shamouti.
Tree moderately vigorous; leaves large; Shamouti-like in appearance; productive.
This variety is said to have originated in the orchard of Moustafa
Khalili in Kalioubiyah Province, Egypt; whether it occurred as a
seedling or limb sport is not reported. It is preferred to
Shamouti because the tree is more productive and the fruit somewhat
smaller and of finer texture. From descriptions it is evident
that this variety and Maltaise Blonde or Petite Jaffa of North Africa
are very much alike.
Tomango
See under Pigmented Oranges.
Valence san Pepins
See under Cadenera.
Valencia (Valencia Late, Hart Late, Hart's Tardiff) (fig. 4-10)
Fruit medium-large, oblong to spherical; areole ring faint or lacking;
seeds few or none. Well-colored at maturity, but regreens
thereafter under certain conditions. Rind medium-thick,
tough, and leathery; surface smooth to faintly pebbled. Juice
abundant and flavor good but commonly somewhat acid. Fruit
holds exceptionally well on tree with little deterioration in quality
and ships and stores well. Excellent for processing. Latest maturing of all commercial varieties.
Tree vigorous, somewhat upright, large and prolific, but with
alternate-bearing tendency. Very wide range of adaptation.
This variety should not be confused with the Spanish Valencia Temprana and various seedling clones grown in the region of Valencia, Spain.
The total heat requirement for maturity of the Valencia orange is so
high that only in the hottest regions is it satisfied prior to the
succeeding bloom. In the United States, this usually occurs
in Florida, the Lower Rio Grande Valley of Texas, and the low elevation
desert areas of Arizona and California, where legal maturity is normally
attained in January or February, though the fruit may be stored on the
trees for several months thereafter, extending into or through the
succeeding period of bloom. In regions of lower total heat,
however, maturity is later and overlaps the bloom, sometimes by several
months. As a consequence, in most regions where this variety
is grown the trees normally carry two crops—the old, which is ripe or
reasonably close to maturity, and the new, at any stage of bloom to
half-grown or thereabout. In regions of mild winters and
moderately low total heat during the growing season, such as the coastal
belt of southern California, Valencia becomes a summer-ripening fruit,
but with crops that alternate appreciably in amount and somewhat in
fruit size. Because the fruit stores remarkably well on the
trees without much dropping and little loss in quality, it is
practicable in this cool, equable region to extend the harvesting season
through the summer into fall and to ship tree-ripened Valencia oranges
as late as October or early November—17 or 18 months from the time of
bloom.
Presumably associated with its
very high total heat requirement and the relatively high acid content of
the fruit is the fact that the Valencia orange exhibits the widest
range of climatic adaptation of any orange variety of commercial
importance. It is suitable for the heat-deficient, mild,
subtropical climate of coastal southern California, the hot, low
elevation desert regions of California and Arizona, the humid,
semitropical climate of Florida, and tropical climates in general.
As might be expected, Valencia is therefore much the most important
variety of the common sweet orange group and seems likely to remain
so. It is of major importance in both Florida and California
and currently accounts for about half the total orange production of the
United States. It is also of major importance in South
Africa, Australia, and Mexico and of considerable importance in Israel,
Algeria, Morocco, and Brazil. In the 1965-66 season,
production was 48.9 million boxes (90-1b) in Florida and 19.3 million
boxes (75-1b) in California and Arizona. Including production
elsewhere, a conservative estimate of the current world production of
this variety would appear to be not less than 100 million 70-pound box
equivalents. In Florida, approximately 80 per cent of the
crop is processed for juice products, whereas in California about
two-thirds is shipped fresh.
The
common assumption that this variety is of Spanish origin is not
supported by the evidence. While varieties of similar
appearance exist in the Valencia region of Spain and elsewhere, none is
characterized by the lateness of maturity of Valencia. Berna,
which approaches it in late maturity, is altogether different in other
respects. Valencia Temprana, the only Spanish variety with
the name Valencia, is an early ripening fruit of smaller size and
flatter form that is no longer propagated (Gonzalez-Sicilia, 1963, pp.
198 and 201). Moreover, Gonzalez-Sicilia states (1963, p.
211) that the Valencia variety originated in the United States and was
introduced into Spain by the Estación Naranjera de Levante at Burjasot,
near Valencia.
The English nurseryman,
Thomas Rivers of Sawbridgeworth, imported this variety from the Azores
Islands and catalogued it in 1865 under the name Excelsior (Coit,
1915). About 1870, he provided trees to S. B. Parsons, a Long
Island Nurseryman, and in 1876 he sent trees to A. B. Chapman of San
Gabriel, California. In the meantime, Parsons sold trees to
E. H. Hart of Federal Point, Florida, where in 1877 the variety received
the name Hart's Tardiff. According to Webber (1943, p. 523),
the trees received by Chapman were unlabeled and included several
varieties, one of which proved to be late maturing and was provisionally
called Rivers Late. A few years later Chapman changed the
name to Valencia Late at the suggestion of a Spanish visitor who
pronounced it similar to a late-maturing variety in the region of
Valencia. It was not until several decades later that
comparisons in California established the fact that these two
indistinguishable varieties were identical and much later that this fact
received recognition in Florida.
While this variety can be traced back to the Azores, it seems unlikely
that it originated there and probable that it came from
Portugal. That likelihood has been greatly strengthened by
the recent discovery there of an old variety that is indistinguishable
from Valencia, which has been named Don João (Galvão, 1943; Chapot, 1963c).
Byron O. Clark (1916) appears to have been the nurseryman most
responsible for the popularization of the Valencia orange in California. The
first commercial orchard was established near Placentia about 1880 when
R. H. Gilman converted a young planting of five acres to the new
variety by top-budding. The first carload of Valencia oranges
shipped to eastern markets, however, is reported to have been sent in
1877 by J. R. Dobbins of San Gabriel.
Other varieties that are indistinguishable from Valencia include Lue Gim
Gong and Pope of Florida, Natal of Brazil, Calderon of Argentina, and
Harward of New Zealand. Two of these—Lue Gim Gong and
Harward—are known to have originated as Valencia seedlings and doubtless
represent nucellar selections of that variety.
As would be expected in a clonal variety of such extensive propagation
and wide distribution, bud variation of Valencia has given rise to a
number of mutant varieties, among which are Armstrong and Perry of
California, Muden of South Africa, and Seedless Valencia of
Australia. Ksiri, a seedless mutation, has recently been
reported in Morocco (Merle, Chapot and Huet, 1964).
For some decades past, clonal selections have been widely used in both
Australia and California and presumably to some extent
elsewhere. Those currently most popular in Australia are
reported to be Berri, Lord Howe, and Norton or Chaffee. These
and St. Ives, a selection used in coastal New South Wales, all trace
back to outstanding trees propagated from introductions made by the
Chaffey Brothers of California in the early 1890's for use in their
nursery operations at Mildura, Victoria. Another selection is
Chapman, which came direct from California. Levitt reports
that when grown side by side at the Narara Horticultural Research
Station, New South Wales, these Australian clonal selections have been
indistinguishable and without significant differences in performance or
behavior.4 Under
the arid conditions of the lower Murray River Valley, however, they
hold their color and juice qualities later into the summer and fall than
other selections.
The principal five
old budline clonal selections in California have been Azusa, Randall,
Hardison, San Marino, and Sespe. The latter three closely
trace back to the original tree at San Gabriel and are not more than two
or three bud generations removed from it. Azusa is
undoubtedly not far removed from the original tree, but the parent tree
is unknown. Randall is known to have been introduced from
Florida in 1903 as Hart's Tardiff, the name given to this variety there
in 1877. Distinctive differences between these California
clonal selections are not discernible.
In recent years, most of the trees planted in California have been of
nucellar budlines, which are virus-free, more vigorous, and commonly
more productive. Currently the most popular of these are
Cutter, Frost, and Olinda. The latter two are
indistinguishable, but Cutter appears to be somewhat more vigorous,
presumably because of its more recent origin. Campbell is
also popular and outstandingly vigorous. In the opinion of
the writer, however, the parent clone differs from Valencia and
constitutes a separate variety.
Verna
See under Berna.
Vicieda (Viciedo)
Fruit medium-small, short-oval; base with shallow radial furrows;
occasional areolar ring; moderately seedy. Color light
orange. Rind medium-thin and finely pebbled. Flesh
color pale; texture somewhat fibrous; not very juicy; well
flavored. Early midseason in maturity.
Tree medium-large and moderately productive, but with marked tendency to alternate bearing.
This old Spanish variety, which is also grown to some extent in Morocco
and Algeria, is declining in importance in favor of superior varieties.
An unnamed improved selection of Vicieda is recognized
(Gonzalez-Sicilia, 1963) in which the basal radial furrows are lacking,
the rind is thinner, smoother, and better colored, the flesh juicier,
and the seed content lower. Indeed, there is reason for the
conclusion that Vicieda consists of a group of clones, some of which are
much better than others.
Minor Common Orange Varieties.—Common
orange varieties of lesser commercial importance or more local interest
than those discussed in the preceding subsection are presented below.
Arancio Barile
See under Barile.
Armstrong (Armstrong Seedless Valencia, Mohn)
Presumably a bud variation of Valencia, Armstrong is a Californian
variety indistinguishable from the parent except that the fruit is
virtually seedless (very occasionally a seed). The parent
budded tree was found about 1928 in the orchard of Pearl C. Mohn at
Anaheim, California. The new variety was patented in 1935
(Patent No. 124) and was introduced by the Armstrong Nurseries of
Ontario in 1939. It has not achieved much importance,
presumably because the parent variety is so nearly seedless (none to
five or six seeds).
Aziza
This Moroccan variety is a beledi
selection or unknown origin that was formerly of local importance and
has now been replaced largely with better varieties. The
fruit matures in midseason and is nearly seedless, medium-small, and
oblong to oval, with a medium-thick, tightly adherent
rind. The flesh is tender, melting, and of good
flavor. The tree is moderately vigorous, somewhat upright,
and possesses an alternate bearing tendency.
Bailidge
The tree of the Bailidge variety is vigorous and productive, yielding
an attractive, medium-large, very few-seeded, midseason-ripening
fruit. As in the case of Clanor, this South African variety
also traces back to old, layered, seedling orange trees, in this
instance three adjoining and indistinguishable trees on the property of
Bailey and Cumberlidge near Rustenburg in western
Transvaal. The date of its selection and the person
responsible are unknown. Late to come into bearing and
mediocre in quality. Bailidge is no longer popular except in
the eastern Cape Province region.
Barile (Arancio Barile)
This old Italian variety is of unknown origin and was never important
except in the Adrano district, where it has been little planted for many
years. Barile is a few-seeded, medium-sized, late midseason
fruit that is distinctive in form in that it is oblong-oval with a
furrowed neck or collar. The rind is of medium thickness,
moderately pebbled, and bright orange in color. The flesh is
firm and of agreeable flavor. Of medium vigor and size, the
tree is not very productive. Chapot reports that this variety
markedly resembles the Shamouti of Israel and is closely related, if
not identical.5
Best (Best Seedless)
Best is one of a number of varieties of local origin or selection that
are considered promising in New Zealand. Such varieties
currently comprise about 20 per cent of the sweet orange acreage in that
country. Best is a virtually seedless fruit of early
midseason maturity and is characterized by the frequent presence of a
navel, juicy flesh, and rich flavor. The tree is vigorous and
productive. The variety originated as a rootstock seedling
of unknown parentage on the property of a Mr. Best at Avondale,
Auckland.
Bibile (Bibile Seedless)
A variety with seedless fruit of good rind texture and quality, Bibile
originated as a seedling in the Bibile district of Ceylon. It
was found by A. V. Richards, government horticulturist, and named and
introduced in 1949 (Richards, 1949).
Blanche de Teneriffe
See under Tenerife.
Boone (Boone's Early, Giddings)
A very early ripening, light-colored, moderately seedy fruit of medium
size and good flavor, Boone was popular in the early decades of the
Florida industry but was soon superseded by Parson and
Hamlin. According to Webber (1943), the fruit is highly
variable, poorly colored, and drops badly following
maturity. The variety is said to have originated as a
seedling selected by a Mr. Giddings near Webster and was first
propagated by David Collins of that locality under the name
Giddings. It was promoted under its present name in 1889 by
C. A. Boone of Orlando, but has not been planted for many years.
Branca
See under Prata.
Burton (Helen Burton)
This South African variety produces a virtually seedless, high quality,
medium-sized fruit of midseason maturity. The tree is
vigorous, upright-growing, large, densely foliated, and
productive. Burton originated as a seedling of Cape Seedling
parentage in a small planting originally owned by Mrs. Helen Burton at
Clanwilliam, western Cape Province. The selection was made in
1954 by G. Joubert, field officer at Citrusdal for the South African
Cooperative Citrus Exchange. This new variety is considered
promising and a few young plantings currently exist in western Cape
Province.
Butler
Fruit medium-large, oblong to ellipsoid; color light orange; moderately
seedy. Flesh juicy and well flavored. Early
midseason in maturity.
Tree vigorous, large, and productive.
This Arizona variety apparently originated from seedlings imported from
Florida about 1895 and was found about 1915 in the orchard of Robert
Butler near Phoenix. It was first propagated about 1925 and
is currently the most popular early season variety in central Arizona.
Cadena Punchosa
A moderately seedy, midseason Spanish variety that much resembles
Cadenera, Cadena Punchosa is inferior in that the fruit is much
seedier. In addition, Gonzalez-Sicilia (1963) reports that
the juice content is lower, the flavor less rich, and the season of
maturity a little later. Chapot reports that in Morocco these
differences are not evident. Cadena Punchosa has largely
been replaced with less seedy varieties and is no longer planted.6
Calderon
This late-ripening Argentinian variety so closely resembles Valencia
that the two are virtually indistinguishable. The fruit is
medium-sized, well-colored, and has few seeds. The tree is
vigorous, large, round-topped, and productive. A
comparatively new variety, Calderon is reported to have originated as a
chance seedling that came to notice in a seedling orchard near
Resistencia, Chaco Province. It is rapidly increasing in
popularity and during recent years has been planted extensively in
Misiones Province and to some extent in the Concordia district of Entre
Ríos Province.
Campbell
This Californian variety is commonly and, in the opinion of the writer,
erroneously called Campbell Valencia. The fruit is
indistinguishable from Valencia, but the tree exhibits certain
consistent, discernible differences in vigor and behavior in comparison
with Valencia. In trials of the two parent clones and of
nucellar clonal budlines of comparable age, the trees of Campbell have
consistently been more vigorous, thornier, larger, broader-topped, and
slower to come into bearing than Valencia. The fruit has also
been slightly lower in juice content than Valencia in the coastal
region and has exhibited a greater tendency to regreen in the interior
districts (Lombard, 1663). Moreover, in a trial at Santa
Paula, Campbell is reported to have shown a higher, though small,
percentage of fruits that were creased or of a chimeric
nature. These differences, however, might possibly relate to
infection by the stubborn virus.
The
parent tree came to light about 1942 in the Early Campbell orchard near
Santa Ana, which was planted in 1871 (Bitters, Batchelor, and Foote,
1956). Almost certainly it was a seedling, for budded trees
were little used at that time, which was five years before the
introduction of the Valencia variety in California. The
possibility that the orchard could later have been topbudded to Valencia
is remote, for trees propagated from roots of this tree some years ago
have shown no differences whatever from those propagated from the
top. And, finally, there are the differences noted in the
trials.
During recent decades
Campbell has been planted considerably in California. More
recently, the Campbell nucellar budline has achieved
popularity. This seedling is indistinguishable from Campbell,
but is more vigorous, thornier, and considered to be of nucellar
origin. It was derived some time prior to 1942 by H. S.
Fawcett at the Citrus Research Center, Riverside,
California. It should probably be called Fawcett Campbell.
Capuchina (Capucin)
This Spanish variety produces a medium-small, oblong to oval fruit of
low seed content, very sweet flavor, and midseason
maturity. Capuchina is still of local importance, primarily
in the Orihuela district of Alicante Province, but it is no longer
planted.
Casa Grande (Oasis)
Casa Grande is an early ripening, highly productive Arizona variety,
the fruit of which is medium-small and moderately seedy. The
tree is vigorous, upright, somewhat thorny, and yields heavily.
The variety originated as a dooryard seedling in Casa Grande, attracted
attention about 1925, and was first propagated by C. J. Wood, who made a
commercial planting in the Salt River Valley in 1930. A few
small plantings have been made in recent years, but this variety seems
unlikely to become important.
Conner (Conner's Seedless)
The Conner is a medium-small, nearly seedless, midseason
fruit. This variety, which is of exceptional tree vigor,
originated as a seedling in the old orchard planted about 1879 near
Glenwood, Florida, from which the Hamlin variety came to
light. Webber (1943) considers the Carlton variety identical
to Conner. Conner was popular for some decades and old
orchards still remain.
Croc (Croc 25)
This South African variety has a very early ripening, moderately seedy
fruit of good flavor, and is of interest primarily because it originated
as a limb sport in a Washington navel orange
tree. Though seedier, it bears considerable resemblance to
the Marrs variety of Texas, which is of similar origin. Croc
came to light comparatively recently in one of the orchards of the
Crocodile Valley Citrus Estates near Nelspruit, eastern Transvaal, where
the only commercial planting occurs.
Cutter Valencia (Cutter Nucellar Valencia)
This California nucellar seedling was derived about 1935 by H. S.
Fawcett of the Citrus Research Center, Riverside, from an outstanding
old Valencia tree in the J. C. Cutter orchard at
Riverside. This seedling budline was released in 1957 and is
currently popular. Cutter is exceptionally vigorous and
thorny and somewhat slow to come into bearing.
Dacre
Dacre is a local midseason variety in New Zealand. The fruit
is medium to medium-small, low in seed content, juicy, and of good
flavor. The tree is vigorous and productive.
The variety originated as a seedling of unknown parentage on the
property of a Mr. Dacre in the Bay-of-Islands district of northern New
Zealand.
Delicious (Partin Delicious)
An early maturing fruit with considerable resemblance to Parson,
Delicious is smoother in rind texture, deeper in flesh color, and
contains fewer seeds. The fruit also holds better on the tree
without dropping or loss in quality. The tree is vigorous,
unusually upright, and productive. According to Ziegler and
Wolfe (1961), this Florida variety traces back to a seedling of unknown
origin that came to the attention of Clay S. Partin about 1900 and has
been propagated ever since for use in the Partin family
holdings. It was introduced commercially in 1958 by the
Lilian S. Lee Nurseries of St. Cloud. It is considered to be
promising.
Delta
This South African variety produces a seedless fruit of high quality
that resembles the Valencia but matures somewhat earlier. The
tree is vigorous and productive. Delta originated as a
dooryard seedling. It is thought to be of Valencia parentage
and was found in 1952 by A. Smith, Government Entomologist, at
Rustenburg, western Transvaal. It is considered to be
promising and has already been planted to some extent.
Diller
Fruit small to medium, oblong to slightly ellipsoid; seeds
comparatively few. Color bright orange. Rind
medium-thick and moderately pebbled. Flesh well-colored,
juicy; flavor good. Early in maturity.
Tree moderately vigorous; short, thick, upright-growing branchlets and
leaves; productive under desert conditions. Said to be above
average in cold tolerance.
This
Arizona variety originated as a seedling of Florida origin in the
orchard of Daniel Diller near Phoenix and was selected in 1910 and
introduced about 1920. It soon became popular as an early
variety in the Salt River Valley, where the 1965 planting was said to be
about 1,000 acres.
Diva
The fruit of this late-ripening Brazilian variety is medium-sized, firm
but juicy, of good flavor, and contains very few seeds. It
is said to ship and keep well. The tree is of medium vigor
and size, upright in growth, and only moderately
productive. Of unknown origin and limited importance, Diva is
considered to be promising.
Don João
This is a very late-ripening Portuguese variety that came to light in 1943 in the Don João quinta (orchard)
near Beja (Galvão, 1943). It is so similar to Valencia that
Eng. Bento Nascimento, director of an agricultural research station at
Tavira in the important Algarve citrus region, lists it in a recent
communication as a synonym for Valencia Late.
Don João traces back to two very old trees, the sole remaining
survivors in 1943 of a larger planting. The fruit of these
trees was very late in maturing and held well on the trees through
summer without loss of quality. The writer recently visited
this orchard and found only one tree remaining. The tree is
thought to be not less than eighty years old and may be older, although
it has been neglected for many years, severely pruned, and does not look
that age.
The writer found young,
bearing Don João trees alongside Valencia at both the Tavira and Setúbal
citrus research stations to be indistinguishable. He
considers the possibility good that they are the same, since contrary to
popular belief the evidence indicates that Valencia is likewise of
Portuguese origin or introduction (see Valencia). Don João has been much planted in Portugal in recent years and on a small scale in Morocco (Chapot, 1963e).
Du Roi
Du Roi produces a medium-small, moderately seedy fruit and came into
prominence in the early period of the Florida citrus industry, primarily
because of its medium-late maturity. It was soon replaced by
Valencia, however. Widely distributed to other countries, it
achieved commercial importance principally in South Africa where old
orchards still remain, though it has not been planted for some decades.
The origin and history of Du Roi are obscure, but according to Webber
(1943) it was probably introduced into Florida from the Mediterranean
basin by the Thomas Rivers Nursery of Sawbridgeworth, England.
Early Shamouti
See under Kinarti.
Enterprise (Enterprise Seedless)
Enterprise produces a medium-small, commercially seedless, early
ripening fruit. The variety was prominent in the early period
of the Florida industry. It is still sparingly planted in
Brazil, but has largely been replaced by Hamlin.
Enterprise originated as a seedling in an orchard at Glenwood, Florida,
near De Land. It was recognized as promising about 1880 and
named for the nearby town of Enterprise. In arid climates,
the fruit is too small to compete with other and better varieties.
Escalon
This Mexican variety produces a seedy, oblong fruit of midseason
maturity that has a smooth rind and good color and
flavor. Escalon is believed to have originated as a seedling
selection in Jalisco State, where it is currently the most popular
variety.
Folha Murcha
This is a late-ripening Brazilian variety with fruit that markedly resembles the Valencia.
The tree is moderately vigorous, upright in growth, with stout
branchlets and large dark green leaves that give it some resemblance to
Shamouti. The leaves, however, are rolled and appear to be
wilted, from which the name (withered leaf) is derived. Folha
Murcha is very productive. Of unknown origin and presumably a
bud variation, this unusual variety is currently of minor importance
but is considered promising.
Frost Valencia (Frost Nucellar Valencia)
Frost Valencia is a nucellar seedling derived about 1915 by H. B. Frost
of the Citrus Research Center, Riverside, and released in
1952. Exceptionally vigorous and productive, it is the oldest
of the California nucellar budline selections and currently the most
popular.
Fukuhara
This Japanese variety produces a moderately late-maturing, occasionally
navelled fruit of medium size, deep color, high juice content, and
rich, sprightly flavor (sugar and acid both high), with few
seeds. The tree is vigorous, productive, and more
cold-tolerant than other late ripening varieties.
Fukuhara was found by S. Fukuhara in Chiba Prefecture in 1922, but it
was not until six years later that K. Noro called attention to its
desirable features. While its parentage is unknown, it is
believed to be a bud variation of the Joppa variety. It is
grown to some extent on Kyushu Island and in Wakayama Prefecture of
Honshu Island, where it is recommended as a late-maturing variety.
Fuya Menuda (Hoja Pequeña, Oranger des Baleares, Oranger de Soller)
An interesting Spanish variety, apparently originating in the Balearic
Islands, Fuya Menuda is highly ornamental because all parts of the
plant—tree, leaves, and fruit—are markedly reduced in
size. It constitutes the only truly dwarf sweet orange
variety known to the writer.
Giddings
See under Boone.
Harward Late (Harward Valencia)
This New Zealand variety is a seedling of Valencia with fruit that is
indistinguishable from its parent. The tree is vigorous,
large, and productive, and since its overall performance is thought to
be superior it seems likely to replace Valencia in New Zealand.
Harward Late originated at Tauranga and probably represents a clonal
budline of nucellar seedling origin. The name Harward
Valencia would therefore seem more appropriate.
Hoja Pequeña
See under Fuya Menuda.
Johnstone Valencia
This South African clonal selection is an outstanding Valencia tree on
the place of Mrs. J. Johnstone at Zuurplaats, near Rustenburg, western
Transvaal. Reported to be the most popular South African
selection currently in use, it scored highest in the Citrus and
Subtropical Fruit Research Institute trial held at Alkmaar (Marloth,
Basson, and Bredell, 1964).
Jordan
This Arizona variety resembles Butler but the fruit is less
seedy. It was discovered about 1925 in the orchard of Mrs. S.
E. Jordan near Phoenix and was introduced about 1930. Of
unknown parentage, it is thought to be either a seedling or bud
variation of Butler and is finding favor as a substitute for it.
Kinarti (Kinnereth, Early Shamouti)
The Kinarti of Israel produces a Shamouti-like but smaller,
smoother-skinned, and earlier-ripening fruit. The variety was
found a few years ago as a limb sport of Shamouti in a small orchard in
Kinnereth Colony near Lake Tiberias. Although of good
quality, it bears poorly and has not achieved commercial importance.
Kinnereth
See Kinarti above.
Ksiri
This Moroccan variety is considered to be a bud mutation of Valencia
(Merle, Chapot, and Huet, 1964), but the fruit is smaller and much
flatter (subglobose to broadly oblate), the rind is smoother and more
tightly adherent with a tendency toward persistence of the style, and
seeds are completely lacking. The flesh is juicier and both
sugars and acids are somewhat higher. The maturity season is
fully as late as Valencia, possibly somewhat later. The fruit
holds well on the tree, which is less upright and vigorous than
Valencia but with larger, broader, and more round-pointed leaves.
Ksiri is a comparatively new variety that was found as a single tree in
a young, bearing Valencia orchard in the region of Mechra Bel Ksiri.
Lamb (Lamb's Summer)
Lamb is a very late-maturing Florida variety. The fruit is
medium-small, ovoid to ellipsoid, contains very few seeds, and holds
well on the tree with little loss in quality. According to
Webber (1943), this old variety originated as a seedling in the nursery
of a Mr. Lamb in Volusia County and was named by a neighbor, E. O.
Painter, who recognized its distinctive characteristics. It
did not attain much importance and has not been planted for many years.
It is of interest to note, however, that Moreira and Filha (1963) and
other Brazilian specialists have recently expressed the opinion that
Pera, currently the principal variety there, is probably the same as
Lamb.
Late Shamouti
This late-ripening, Shamouti-like variety originated in Israel as a bud
sport of Shamouti. Its history is not available to the
writer. Because of its late maturity (approximately the same
as Valencia), it is considered to be promising and is now under
commercial trial in Israel.
Letaba (Letaba Early)
The South African Letaba variety produces a richly flavored, moderately
seedy (as compared with Pineapple), medium-large fruit of early
midseason maturity. It is included here primarily because of
its commercial importance in the extensive plantings of the Letaba
Estates in northeastern Transvaal and because it is superior to
Pineapple in important respects. Its origin is unknown, but a
resemblance to Pineapple suggests that it is a selection of that
variety.
Lue Gim Gong
This so-called Florida variety in all respects is indistinguishable
from Valencia. In all probability, it represents a nucellar
clonal budline of that variety and hence should be called Lue Gim Gong Valencia.
According to Ziegler and Wolfe (1961), at the time of its introduction
in 1912 it was claimed to be a hybrid of Valencia and Mediterranean
Sweet, made at De Land in 1886 by a Chinese gardener of that
name. It was said to mature later than Valencia and hold
better on the tree, neither of which claims have proven to be
true. It is still planted to a limited extent in Florida,
however.
Mazizi
See under Yousef Solimon.
Mediterranean Sweet (Sanford's or Florida Mediterranean Sweet)
This variety has medium-large, well-colored fruit of low seed content
and late midseason maturity. It was widely planted in Florida
in the early period of the citrus industry and some old orchards still
exist. According to Webber (1943), the variety was introduced
by H. S. Sanford from Mediterranean Europe about
1875. Although the seasons of maturity are similar, it is
altogether different from the Garey's or California Mediterranean Sweet,
which appears to be the distinctive old Maltaise Ovale variety of the Mediterranean basin.
Midknight (Midnight Valencia)
Midknight is a virtually seedless, medium-large, somewhat oblong fruit
of excellent quality and medium-late maturity. Marloth and
Basson (1955) regard this South African variety as an early Valencia
selection and it is commonly called Midknight Valencia. Since
it ripens earlier than Valencia and does not fruit in clusters to the
same degree, it is probably best considered a variety. The
tree is moderately vigorous and upright-growing, with large, broad
leaves, but not as productive as standard Valencia.
It originated on the place of A. P. Knight at Summerville, Addo,
eastern Cape Province, as a selection from a rather variable lot of
budded trees ordered from Westfalia Estates (northern Transvaal) in
1927. Unfortunately, more than one clone seems to have been
propagated under the same name, for two are now recognized—that
characterized above and another of which the fruit is round and the tree
less vigorous and more spreading. Neither clone is currently
of much importance.
Mohn
See under Armstrong.
Moss
This South African variety is a Cape Seedling selection made several
decades ago by H. E. Moss of Grahamstown, eastern Cape
Province. The fruit somewhat resembles Valencia but is
seedier and ripens earlier. The parent tree is reported to
have been about a century old at the time of its
selection. It has not been planted much and is no longer
recommended.
Muden
Muden produces a medium-small, comparatively few-seeded, round fruit of
midseason maturity. The tree comes into bearing very early
and is regularly and heavily productive. The fruit does not
hold well on the tree, however, and fruit size diminishes appreciably as
the tree ages. This South African variety originated as a
limb sport of Valencia in an orchard of the Golden Valley Citrus Estate
at Muden, Natal Province. Muden was found and first
propagated in 1945. It was rather extensively planted at
Muden and in eastern Cape Province for a time but has been little
propagated in recent years.
Oasis
See under Casa Grande.
Olinda Valencia
This California selection is a chance seedling, presumably of Valencia,
found by H. J. Webber and L. D. Batchelor of the Citrus Research
Center, Riverside, in the dooryard of O. Smith at Olinda in 1939 and
released in 1957. It is indistinguishable from Frost Valencia
and hence is considered to be of nucellar origin. Olinda is
currently popular in California.
Omana Jaffa
Omana Jaffa is a local selection of Jaffa that is currently popular in
New Zealand as a late midseason variety.
Oom Louis
This South African variety is a medium-sized, comparatively few-seeded,
globose to oblong, very juicy fruit of midseason
maturity. The tree is vigorous, early bearing, and
productive. Fruit quality is excellent on Empress mandarin
rootstock but poor on rough lemon. Oom Louis originated as a
chance seedling of Cape Seedling parentage on the property of the South
African Railways near Hectorspruit station, eastern Transvaal, where it
was selected by L. P. deVilliers of Nelspruit in 1944. It has
been planted commercially to some extent in eastern Transvaal.
Oranger des Baleares
See under Fuya Menuda.
Oranger de Soller
See under Fuya Menuda.
Ovaletto di Calatafimi
This is a long-oval, late-maturing, usually seedless fruit of medium
size and good quality. The variety came to notice in the
Calatafimi district near Tropani, Sicily, sometime between 1910 and
1920. It is considered to be a derivative, probably a bud
mutation, of the Calabrese Ovale variety (Fatta Del Bosco, 1963).
Pajarita (Pajarito)
The Pajarita of Spain is a moderately seedy, medium-small,
comparatively thick-rinded fruit of relatively low juice content,
mediocre quality, and midseason maturity. It is an old
variety that has long been replaced with better varieties.
Paperrind (St. Michael, Paper Rind St. Michael, San Miquel)
The fruit of this midseason California variety is small-sized,
moderately seedy, juicy, and well-flavored. The rind is very
thin, leathery, and smooth. The tree is vigorous, upright,
and productive.
Said to have
originated on the Island of St. Michael, Azores Islands, presumably as a
seedling, this variety was named and introduced about 1870 by T. A.
Garey, pioneer citrus nurseryman of Los Angeles. Along with
Garey's Mediterranean Sweet, which ripens earlier, it soon attained
importance as a midseason variety filling the gap between the early
Washington navel and the late Valencia oranges. As the
California industry expanded with overlapping production of the latter
two superior varieties, the popularity of Paperrind and Mediterranean
Sweet declined and both have now virtually
disappeared. Although widely distributed to other countries,
Paperrind seems to have achieved importance elsewhere only in Mexico,
where it is known as San Miquel.
Partin Delicious
See under Delicious.
Paterson (Paterson River)
The Paterson is an Australian selection of Parramatta Seedling that
originated on the Paterson River near Maitland, New South
Wales. Characterized by uniformity in shape and quality, this
variety became popular following World War I, but has largely been
replaced by the Washington navel. Commercial plantings have
not been made for several decades, although some old orchards still
remain.
Peret (Berna Peret, Vernia Peret, Pereta)
A comparatively new, late-maturing seedless variety, the fruit of Peret
of Spain is indistinguishable from Berna, but according to
Gonzalez-Sicilia (1963) colors earlier and more intensely and is juicier
and sweeter. These differences have not been confirmed in
limited comparisons in Morocco.7 The
tree is said to be more vigorous, larger, and more regularly productive
than Berna but somewhat less cold-resistant.
This variety is reported to have been found in an old seedling orchard
in the Vergel district of Alicante province about 1911, but it was not
propagated and promoted until much more recently. It is
currently planted to some extent in northern Alicante and southern
Valencia provinces.
Perry
The Perry of California is a limb sport of Valencia with fruit which is
deeper in color (reddish-orange) and matures somewhat
later. It originated in the Perry orchard at Fillmore and was
discovered by Howard Lorbeer of that community about
1956. It appears to be promising and is currently under
trial.
Plaquemines
This Louisiana variety is a seedless budsport of
Pineapple. The two varieties are indistinguishable in
appearance, but the fruit of Plaquemines averages slightly smaller, the
rind is a little thicker, and maturity is somewhat later.
The Plaquemines variety is one of twenty-three limb variations found in
Pineapple trees at the Magnolia Orange Grove near Port Sulphur,
Plaquemines Parish, and put under study in 1948. Propagated
soon thereafter and fruited for some years, it was released by the
Louisiana Agricultural Experiment Station in 1960 (Hawthorne et al., 1960).
Prata (Branca)
Prata produces a medium-large, spherical, highly seedy fruit of good
flavor. The distinctive feature of this variety and reason
for its inclusion here lies in its pale yellow color. It is
an old variety of very limited importance in Spain and Portugal, found
elsewhere only in collections.
Robinhood (Robin Hood)
This South African variety produces a medium-sized, oblong to slightly
oblique, virtually seedless, very juicy fruit of excellent quality and
midseason maturity. The tree is vigorous and
productive. Robinhood traces back to a budded parent parent
tree of the Jaffa type on the farm of a Mr. Pursglove in the Karino area
of eastern Transvaal, which he recognized as superior and decided to
propagate several decades ago. Because of budunion "crease,"
it should be grown on rootstocks other than rough lemon. A
few commercial plantings exist in the Lowveld portion of the region of
its origin.
St. Michael
See under Paperrind.
San Miquel
See under Paperrind.
Seedless Valencia
This Australian variety is a bud variation of Valencia that differs
from it in that the fruit is more oblong or oval in form, less seedy
(occasionally one or two seeds), and matures earlier (late
midseason). The tree is vigorous and upright with large
leaves that tend to be bunched, giving it a distinctive appearance, and
is strongly alternate-bearing.
Seedless Valencia is said to have been discovered in the orchard of W.
Eathers at North Richmond, New South Wales, between 1920 and
1925. Limited commercial production occurs in Gosford and
other districts near Sydney, but this variety is unlikely to increase
much in importance because of its alternate crop habit.
Siletta
See under Seleta.
Tenerife (Blanche de Teneriffe) (fig. 4-11).
The Tenerife variety of Spain produces a medium-sized, moderately
seedy, midseason fruit of good quality that is pale yellow in color
rather than orange. An old variety that appears to have
originated in the Canary Islands, it early spread to other
countries. In several countries, Tenerife has received
favorable reports, but nowhere has it become commercially
important. Currently, it is considered to have promise in
Egypt.
Torregrosa
A moderately seedy, midseason fruit that resembles Cadena Punchosa, the
Spanish Torregrosa is inferior in that it is somewhat smaller, the rind
is much thicker, the juice content is lower, and the flavor more
acid. It was long ago replaced with better varieties.
Trovita
This
California variety is believed to be a Washington navel orange
seedling. The fruit is early maturing, medium-small,
few-seeded, juicy, and pleasantly flavored. The tree is
vigorous, upright-growing, and productive, but with a tendency to
alternate bearing.
Trovita originated
as a seedling from a fallen fruit, presumably of Washington navel, at
the Citrus Research Center, Riverside, California, in 1916 and was
released in 1935. It was selected in 1928 and described and
named by H. B. Frost, the name being Esperanto for "found." In
comparison with the parent variety, the fruit is smaller, juicier, and
of milder flavor. The tree is more productive under desert
conditions. Trovita has achieved little importance in
California, but is said to be promising as an early juice variety in the
Negev region of Israel and elsewhere.
Valencia Temprana
This Spanish variety produces a virtually seedless, small-sized, juicy
fruit of good flavor that is early midseason in maturity. It
was long ago replaced with better varieties and is included here because
it is the only Spanish variety of that name and obviously altogether
different from the California-named Valencia variety of worldwide
importance.
Westin
The fruit of this Brazilian midseason variety is medium-small,
virtually seedless, especially well-colored (deep orange), juicy, and
richly flavored (relatively high acidity). The shipping
quality is reported to be good. The tree is vigorous,
spreading, large, and very productive.
Formerly known as Clementina,
to avoid confusion with the well-known Clementine mandarin, it was
recently renamed in honor of Professor Philippe Westin Cabral de
Vasconcellos and is considered to be among the most promising midseason
varieties for Brazil.
Yousef Solimon (Mazizi)
This Egyptian variety produces fruit similar to the Egyptian baladi,
but it is less seedy, the rind is thinner and of smoother surface
texture, the flesh is juicier and richly sweet with less acid, and the
fruit is earlier in maturity (early midseason). The tree is
moderately vigorous, medium-large, and upright-growing, with somewhat
sparse foliage that consists of long, narrow leaves. Yousef
Solimon is an irregular and poor bearer.
This variety was found in a baladi seedling
orchard in Upper Egypt owned by Yousef Solimon and is popular in the
local markets because of its rather distinctive flavor.
Zegzel
This Moroccan variety is a midseason, seedling clone. The
fruit is medium-sized, subglobose to round, well-colored, and seedy,
with roughly pebbled, easily peeled rind of medium thickness and juicy
flesh of good flavor. The fruit holds well on the tree, with
little loss in quality though with some puffing of the
rind. The tree is vigorous, highly productive,
upright-growing and large, with dense foliage consisting of large
leaves.
An old beledi selection
that originated in the Zegzel Valley of eastern Morocco, Zegzel
formerly was of considerable importance and exported to
Europe. The variety is now only of local popularity and no
longer propagated. It is of interest to note that Zegzel has
been grown almost entirely as seedling trees.
Sugar or Acidless Oranges
The sugar or acidless oranges are a small group of very low acid
varieties that corresponds to the sweet lemons, limettas, and limes
because of their lack of acidity, their insipidly sweet flavor, and the
presence on the seeds of a cream-colored chalazal spot, which is darker
on the more acid forms of citrus and chestnut-brown for the common sweet
oranges (Chapot and Praloran, 1955).
They are variously referred to as the douceâtre or douce (France), sucreña (Spain), Maltese or dolce (Italy), meski (North Africa and the Near East), moghrabi (Near East), lokkum or Tounsi (Turkey), succari (Egypt), and lima (Brazil)
oranges. With the exceptions given above, they are
indistinguishable from the common sweet orange and several have marked
resemblances to certain varieties of that group.8 There
is at least one acidless navel orange variety, however—Bouroubaine
Meski of Tunisia, and a pink-fleshed acidless variety, Vainiglia
Sanguigno of Italy. It has recently been shown, however, that
this latter variety is not a true blood orange since the principal
pigment involved is the carotenoid lycopene rather than an anthocyanin
(Huet and Chapot, 1964). The Mosambi variety of India has
sometimes been regarded as a member of the sugar orange group, but the
dark brown color of the chalazal spot indicates otherwise.
Several independent origins are suggested for the sugar orange since at
least three varieties so closely resemble varieties of the sweet orange
as to strongly suggest a close relationship. Thus, Shamouti
Meski appears to be an acidless form of the famous Shamouti variety of
the Near East, Maltaise Meski a non-acid form of the Maltaise Blonde of
unknown origin, and there can scarcely be doubt that Bourouhaine Meski
is a derivative from Bourouhaine of Tunisia.
Because of the extremely low acidity of the flesh, sugar oranges attain
edibility as soon as the juice content is moderately well developed and
hence are the earliest to reach the local markets. Moreover,
their peculiar flavor is relished in most Arabic-speaking countries and
to some extent in Spain and Portugal and their former
colonies. As a consequence, their culture has remained
profitable, although they are obviously not suitable for export to major
population centers of Europe or the United States. In the
Mediterranean area, Spain and Egypt are the countries where their
culture is most important, and in the Western Hemisphere they are
popular in Brazil and Mexico. This type of orange may
eventually prove to be valuable for breeding purposes (Soost and
Cameron, 1961).
Major Sugar Orange Varieties.—The
varietal situation for both major and minor sugar orange varieties is
most uncertain, yet it is clear there are a number of varieties, only a
few of which are sufficiently distinctive to be identifiable with
certainty. To judge from the writer's personal knowledge and
descriptions in the literature, the variety most widely grown and hence
most important occurs under many local names which in reality are
synonyms. It is therefore his opinion that some of the
characterizations given below almost certainly relate to the same
horticultural variety.
Canamiel
See under Sucreña.
Dolce
See under Vainiglia.
Grano de Oro
See under Sucreña.
Imperial
See under Sucreña.
Lima
Fruit medium-small, spherical to subglobose; seeds comparatively
few. Rind medium-thick; surface slightly rugose; color light
orange. Flesh color light yellow; tender and juicy; flavor
insipid because of lack of acid. Very early in maturity.
Tree vigorous, large with dense foliage, and highly productive.
Lima is said to be the most important of the three non-acid orange
varieties grown in Brazil, where this fruit is so highly appreciated
that it currently constitutes about 10 per cent of the
plantings. It is accorded particular dietary values for
adults and is reported to be especially popular with children.
Maltese
See under Vainiglia.
Mosambi
See under Mosambi.
Real
See under Sucreña.
Succari (Sukkari)
Fruit small to medium-sized, somewhat oblate to globose;
seedy. Rind medium-thick and surface relatively
smooth. Good color at maturity. Flesh color pale
and juice abundant, but almost devoid of acid. Sugar-acid
ratio of 90-100:1 at maturity. Matures early
(October-December).
Tree vigorous, upright, and productive.
Of unknown origin, Succari has long been popular in Egypt and is of
considerable commercial importance.
Sucreña (Imperial Grano de Oro, Real, Canamiel) (fig. 4-12)
Fruit medium-small, variable in form, but prevailingly subglobose to
spherical; moderately seedy, chalazal spot
cream-colored. Rind medium-thick and moderately
pebbled. Well-colored at full maturity. Flesh
color good at full maturity at which stage juice content is moderately
high. Flavor insipid owing to lack of acidity. Of
comparatively short season, it is commonly harvested prior to full
maturity, at which stage color is pale and juice content and quality
poor. Earliest of all oranges.
Tree vigorous, somewhat upright, medium-large, and productive.
This variety is grown in Spain under a number of names, which reflects
the fact that it has considerable local use though minor economic
importance. The fruit is said to be distasteful to most
palates but much appreciated by those accustomed to it or intolerant of
acid. The vitamin C content is reported to be not appreciably
lower than in other oranges.
Sukkari
See under Succari.
Vainiglia (Vaniglia, Maltese, Dolce)
Fruit medium-small to medium, subglobose to spherical; small apical
depression; seedy. Rind medium-thick and finely to moderately
pebbled. Well-colored at maturity. Juicy and
sweet flavored but lacking in acid and with slight bitterness, though
eating quality generally improves with age. Very early in
maturity.
Tree vigorous, medium-sized, and very productive.
In Italy, this variety is very old and is thought to be of local
origin. Because of its insipidly sweet and faintly bitter
taste, the demand for Vainiglia is said to be very limited and entirely
local.
Of special horticultural
interest is the presumption that it gave rise to the unique,
pink-fleshed, non-acid Vainiglia Sanguigno variety, which is not a true
blood orange.
The similarities
reflected in the characterizations of the four varieties discussed in
this subsection are such as to make it highly likely that they represent
a single clone.
Minor Sugar Orange Varieties.—The following seven sugar orange varieties appear to be the best known among those of local importance.
Bourouhaine Meski
This is a Tunisian variety which Chapot and Huet (1964) state is an
acidless form of the distinctive Bourouhaine navel orange variety,
believed to be native to that country.
De Nice (Orange de Nice)
This sugar orange, a variety of the French Riviera, is so similar to
the Succari of Egypt and Meski of Tunisia as to be indistinguishable to
the writer.
Iaffaoui Moghrabi
See under Shamouti Meski.
Meski
According to Chapot and Huet (1964), Meski is a Moroccan
variety. The writer found it indistinguishable from the De
Nice of France, Succari of Egypt, Mogbrabi of Lebanon, and the common
Meski of Tunisia.
Maltaise Meski
This is a non-acid Tunisian variety that Chapot and Huet (1964) state
is otherwise indistinguishable from the highly distinctive Maltaise
Blonde (Petite Jaffa) variety.
Orange de Nice
See under De Nice.
Piralima
This Brazilian variety is much like the Lima but the fruit is reported
to be somewhat flatter in form, the rind surface smoother and paler in
color, the seed content a little lower, and the tree somewhat more
productive. Of considerable importance and second to the Lima
in Brazil, Piralima is a selection of Lima made in the Piracicaba area
by Professor P. Westin Cabral de Vasconcellos.
Serrana
The Serrana of Brazil is a smaller, oval-shaped, and less juicy fruit
than Piralima, with a thin, very smooth rind.
It is reported to be an unstable clone, presumably chimeric in nature,
that occasionally gives rise to limb sports which produce fruits of
quite different characteristics. Considered to be of local
origin, the Serrana is of limited importance.
Shamouti Meski or Shamouti Moghrabi (Iaffaoui Moghrabi)
Chapot (1954) reports that this Lebanese variety is indistinguishable
from the famous Shamouti (Palestine Jaffa) except that it is seedier and
almost tasteless.
Pigmented Oranges
The pigmented oranges are the blood oranges of the Mediterranean basin (sanguina of Spain, sanguine of French-speaking countries, and sanguigna and sanguinella
of Italy). They differ in appearance from the common sweet
oranges only because under certain conditions the fruit usually exhibits
pink or red coloration in the flesh and juice and on the
rind. The blood oranges, in general, are characterized by a
somewhat distinctive flavor that is much appreciated by connoisseurs and
causes certain varieties to be regarded as among the most delicious of
oranges. The coloration of the blood oranges is associated
with the development of anthocyanin pigments, whereas the pink and red
coloration in the pigmented grapefruits is caused principally by the
carotenoid pigment lycopene. These pigments tend to
deteriorate during processing and impart a muddy color to the juice.
Most blood orange varieties appear to have originated in the
Mediterranean basin, probably first in Sicily or Malta where they have
been known for several centuries. Although grown to some
extent in many of the Mediterranean countries, their commercial culture
is confined principally to Italy, Spain, Algeria, Morocco, and
Tunisia. They enjoy high favor in European markets in general
and are especially popular in central and northern
Europe. The lack of dependability of blood coloration
development in most varieties, however, is currently an important
handicap and, together with technical difficulties in processing the
juice, constitutes the principal deterrent to expansion of their
culture. Neither the producer nor the marketing agency can
guarantee to provide the consumer with a uniform product with respect to
either internal or external pigmentation, which is obviously requisite
to standardization.
The conditions
responsible for the development of the blood coloration are not well
understood and may differ somewhat for the flesh and rind. It
is clear that a certain amount of heat is a requisite, for intense
coloration does not occur in the cool equable coastal region of southern
California. Color development is much less regular and
intense in humid climates, such as Florida, than in arid climates such
as the inland valleys of California where the diurnal fluctuations in
temperature are much greater. Cold storage materially
intensifies flesh coloration. Whereas moderate insolation
seems to favor color development on the rind, intense sunlight appears
to prevent or destroy it. As a consequence, rind coloration
is usually best on less exposed or partially shaded fruit. In
general, therefore, blood coloration in the flesh is most certain and
intense in hot, dry, interior districts of the subtropics and rind
coloration is best on non-exposed fruit. That nutritional or
other factors may be involved, however, is suggested by the observation
that pigmentation is sometimes more intense on the fruit produced by
trees on a particular rootstock and on trees of other kinds of citrus
converted to blood oranges by topgrafting.
Under comparable conditions, however, some varieties are more
dependable in the development of the blood coloration than others and
exhibit more intense pigmentation. Those varieties in which
blood coloration is most regularly and strongly expressed are
commercially preferable and constitute the deep blood group (sanguine of
French-speaking countries). The conclusion that the deep
blood varieties form a natural group has been materially strengthened
recently by the studies of Chapot (1963e). Chapot
reports that the three varieties most certain of blood coloration under a
wide variety of conditions and most intense in pigmentation under
favorable conditions—Spanish Sanguinelli, Tarocco, and Moro—exhibit
purplish-red coloration of the chalazal spot. In contrast,
the other blood varieties available for comparison showed chalazal spot
coloration not significantly different from the normal chestnut-brown of
non-blood oranges. The less dependable and usually less
intensely pigmented varieties comprise the light blood group (sanguinello of Italy, demi-sanguine in French) and are much more numerous and highly variable in behavior.
Blood oranges have originated in three, widely separated areas of the
Mediterranean basin, giving rise to three regional groups, in two of
which parental relationship is either known or indicated. As
described and characterized by Chapot (1963e), these groups are as follows:
The Ordinary Blood Oranges.—This
is the oldest group, almost certainly of Sicilian origin, the fruits of
which are similar to the common sweet orange with the exception of the
blood pigmentation. It includes the very old Sanguinello
Comune and Maltaise Sanguine varieties, many other light blood oranges,
and the much younger Moro and Tarocco deep blood varieties.
2. The Doblefina Varieties.—This group originated in Spain with the Doblefina
(Doble Fina) variety, the parentage of which is unknown, and all
members are derivatives from it and exhibit many of its highly
distinctive characteristics. It consists of the relatively
old parent variety Doblefina, Entrefina, the fairly new Doublefine
Ameliorée (Washington Sanguine), and the very new deep blood Spanish
Sanguinelli varieties.
3. The Shamouti or Palestine Jaffa Blood Oranges.—This
group, smallest of the three, originated in Lebanon or
Syria. Each member is identical with its parent variety with
the exception of the degree of blood pigmentation. It
consists of Shamouti Maouardi, a light blood Shamouti, and Maouardi
Beladi (Damawi), a light blood form of the beladi orange, which gave rise to Shamouti.
Mention should perhaps be made also of two pink-fleshed orange
varieties in which the coloration is caused by the carotenoid pigment
lycopene instead of an anthocyanin. Huet and Chapot (1964)
have recently reported this to be the case in the old Vainiglia
Sanguigno variety of Italy, and Monselise and Halevy (1961) have found a
similar situation in the new Sarah variety of Israel, which originated
as a budsport of Shamouti.
While
specific statistics are not available, Burke (1961) reported that blood
oranges comprised 42 per cent of the Spanish orange production in
1961. Competent observers have estimated that this percentage
is higher in Italy. Allowing for the production in Algeria,
Morocco, and Tunisia, a conservative estimate of the 1965 commercial
production of pigmented oranges appeared to be not less than 30 million
boxes (70-lb equivalents), and probably more. Moreover, from
the trends of recent years, production may be expected to increase
significantly in both Spain and Italy. Because of the
pigmentation of the juice, the blood oranges are not well adapted to
processing and must therefore be marketed fresh.
Some more or less general practices, unique to the production of blood
oranges, may be noted. In some districts in North Africa,
differential harvesting reportedly is employed to separate the pigmented
fruits from the non-pigmented. The most practicable means of
such harvesting is said to consist of picking the north and south sides
of the trees separately. A highly restricted practice which
is said to be used beneficially by some growers in West Pakistan
consists of shading the lower portion of the trees by means of a tall,
rapid-growing covercrop such as sesbania (Sesbania exaltata). This is reported to appreciably increase the percentage of pigmented fruits.
Major Pigmented Orange Varieties.—The principal pigmented orange varieties of the world are presented below.
Belladonna Sanguigno
See under Moro.
Blood Oval
See under Doblefina.
Bloodred (Blood Red Malta)
Bloodred is a seedy, light blood orange of very good flavor, but
without distinctive characteristics, that is widely grown in the Punjab
region of India and West Pakistan and is much prized there and in
northern India. The development of blood coloration is highly
variable and uncertain and is best in the submontane districts, where
the fruit attains good color and excellent flavor.
The origin of this variety is unknown but almost certainly it came from the Mediterranean basin.
Calabrese Sanguigno
See under Tarocco Liscio.
Doblefina (Oval Sangre, Sanguina Oval, Rojo Oval, Sanguine Ovale, Morlotte, Blood Oval) (fig. 4-13)
Fruit medium-small to small, oval to oblong; virtually
seedless. Yellowish orange at maturity, more or less densely
blushed with rose-colored flecks. Rind medium-thick, firm and
leathery; surface very smooth and fine-textured; tightly adherent
(difficult to peel). Flesh firm and moderately juicy, with
pink flecks scattered more or less throughout; distinctive fragrance and
mild, pleasant flavor. Fruit hangs poorly on tree and drops
badly, but ships and stores unusually well. Late midseason in
maturity.
Tree small and somewhat
lacking in vigor, spreading and open in growth habit; foliage sparser
and lighter green than most. An early and heavy bearer.
Aside from its short season, lack of juiciness, and other faults, the
Doblefina variety is highly variable and uncertain with respect to
development and intensity of the blood coloration, which is often
deficient or lacking. When well developed, however, the fruit
is attractive.
Of unknown Spanish
origin, Doblefina was for many decades the principal blood orange
variety in Spain and was favorably known in European
markets. It has been losing ground for some years, however,
to other varieties of better color and richer flavor, particularly its
derivative, Spanish Sanguinelli. It is of interest to note
that three blood orange varieties—Entrefina, Doublefine Ameliorée, and
Spanish Sanguinelli—have originated as budsports from Doblefina.
Doublefine Ameliorée (Grosse Sanguine, Washington Sanguine, Washington Sangre, Pedro Veyrat) (fig. 4-14)
Fruit medium-large, oval to oblong, often asymmetric; commonly with
persistent style or small shallow-embedded navel; seeds few and
rudimentary or none. Under favorable conditions external
blood coloration good (better than Doblefina). Rind
medium-thick, moderately smooth, and not as tightly adherent as in
Doblefina. Flesh moderately juicy, but blood coloration
commonly poor or lacking. Flavor good. Holds well
on tree (very much better than Doblefina) and stores and ships as well
or better. Late midseason in maturity.
Tree lacking in vigor, small, very precocious, and productive.
This relatively new variety is said to have originated as a lima sport
of Doblefina that was found by Balthazar Ferrer at Sagunto,
Spain. It has remained a minor variety in Spain, but is
currently the leading blood orange variety in Algeria and
Morocco. The blood coloration is variable and uncertain and
lacking in the Atlantic coastal districts of Morocco.
Entrefina (Inglesa)
Fruit small, globose to very slightly oval; seeds very
few. Color similar to Doblefina, but even less certain in
development of blood coloration. Rind surface less smooth
than Doblefina, but flesh somewhat juicier and fruit holds better on the
tree. Late midseason in maturity.
Tree said to be more vigorous, larger, and more productive than
Doblefina and less subject to dropping of the fruit.
Entrefina is generally considered to be a subvariety or selection of
Doblefina, with which it is often confused. Because of its
smaller size and less attractive appearance, this variety commands lower
prices than Doblefina and has lost materially in importance.
Grosse Sanguine
See under Doublefine Ameliorée.
Inglesa
See under Entrefina.
Maltaise Sanguine (Portugaise)
Fruit medium-sized, oblong to globose; seeds few to
none. External blood coloration well developed under
favorable conditions. Rind medium-thick, moderately pebbled,
somewhat soft, and peels easily. Flesh tender, melting, and
very juicy, with good blood coloration under favorable
conditions. Flavor and aroma excellent. Late
midseason in maturity. Holds on tree only moderately well and
stores and ships poorly.
Tree
moderately vigorous, medium-large, and not very
productive. Some tendency to alternation.
Portugaise is the name employed in Algeria where this variety is
commercially most important, but in Tunisia it is the old and highly
reputed Maltaise Sanguine variety. Almost certainly a number
of clones are involved which are indistinguishable in general, yet
exhibit minor differences in growth habit and fruit form. In
Tunisian usage, Portugaise is considered to be somewhat more upright in
growth habit and with fruit of a slightly more pronounced oval
form. There is a close resemblance between Maltaise Sanguine
and the Sanguinella Moscata variety of Italy.
There is general agreement as to the excellent eating quality and
fragrance of this variety. However, it is highly variable and
uncertain with respect to blood coloration
development. Frequently external red pigmentation is not
accompanied by internal coloration and in some growing areas both are
lacking.
The origin of this
undoubtedly very old variety is unknown, but possibly it may have been
the island of Malta. The Maltese Blood variety introduced
into Florida from the Mediterranean many years ago seems likely to be a
clone of this variety as does the Bloodred Malta of West Pakistan and
Punjab, India. The Egyptian variety Baladi Blood, which is
said to have been imported from Malta about 1830, almost certainly is
Maltaise Sanguine.
Morlotte
See under Doblefina.
Moro (Belladonna Sanguigno) (fig. 4-15)
Fruit medium to medium-large, subglobose, round or obovoid; base
somewhat furrowed; apex commonly flattened; areole faint or lacking;
seeds few or none, but with chalazal spot purplish-red. Rind
medium-thick, moderately adherent, and somewhat
pebbled. Orange-colored at maturity with light pink blush or
red streaks at advanced maturity. Flesh deeply pigmented
(almost violet-red); juicy; flavor pleasant. Very early in
maturity (earliest of the commercial blood oranges), but holds well on
the tree and stores and ships well. A distinctive aroma
develops with advanced maturity, but flavor deteriorates if held too
long in storage and becomes objectionable to some.
Tree of medium vigor and size, spreading and round-topped; very
productive fruit (generally in clusters of three or more).
Moro is distinctive in that pigmentation develops early and strongly in
the flesh, ranging from medium to intense, whereas rind pigmentation
may be lacking or at best only moderately developed. Thus,
the Moro does not develop external pigmentation in the coastal area of
southern California, where conditions are unfavorable to development of
blood coloration, but almost always exhibits far more internal
coloration than any other variety. This variety undoubtedly
belongs to the deep blood group.
Of
comparatively recent Sicilian origin and thought to have developed from
the Sanguinello Moscato variety, Moro did not attain the popularity of
Tarocco for several decades. More recently, it has been
planted to a considerable extent in Sicily, where it now enjoys equal
favor.
Murtera
Fruit medium-small, spherical to slightly oval; areolar ring in many
cases; seeds few. Color orange at maturity with light red
blush. Rind medium-thin with finely pebbled
surface. Flesh juicy but generally lacking in red
coloration. Flavor rich and sweet. Hangs well on
the tree, better than either Doblefina or Entrefina, and ships well. Late midseason in maturity.
Tree vigorous, medium-large, very productive, and hardy; foliage dense
and dark-green in contrast with Doblefina.
The principal fault of this Spanish variety is the poor blood
coloration of both rind and flesh, particularly the
latter. As a consequence, Murtera's popularity has declined
in favor of such better colored varieties as Spanish Sanguinelli.
Oval Sangre
See under Doblefina.
Pedro Veyrat
See under Doublefine Ameliorée.
Portugaise
See under Maltaise Sanguine.
Ruby (Ruby Blood)
Fruit medium-sized, globose to slightly oblong; faint areolar circular
furrow or ridge; seeds relatively few. Well-colored, with reddish
flush under favorable conditions. Rind medium-thick, finely
pitted, and lightly pebbled. Flesh tender and juicy; flavor
rich. Flesh color orange, streaked (rather than flecked) with
red under favorable conditions. Midseason in maturity.
Tree moderately vigorous, compact, medium-large, and productive.
The Ruby variety was introduced from the Mediterranean (country
unknown) to Florida about 1880 and brought to California not long
thereafter. From its appearance and behavior, it may prove to
be an old Italian variety. In both Florida and California,
Ruby is highly uncertain and variable with respect to development of
blood coloration. For this reason, it has not become popular
and remains merely a novelty. In California's coastal region,
it never develops red pigmentation. Ruby is at its best,
with marked variability, however, in hot interior
districts. In such districts, the quality is excellent and
part of the crop colors beautifully.
Several unnamed clones or selections are known to exist which differ in
blood coloration development and other minor respects.
Rojo Oval
See under Doblefina.
Sanguigna Oval
See under Doblefina.
Sanguigno Semplice
Fruit medium-sized, globose; base slightly flattened; moderately seedy;
yellowish-orange, and red-tinted at maturity (more so than Sanguinello
Comune). Rind medium-thick, moderately tough and adherent,
and moderately to strongly pebbled. Flesh juicy, pleasantly
flavored, and streaked with red (much less intensely pigmented than the
rind). Midseason in maturity, but holds well on the tree.
Tree similar to Sanguinello Comune in nearly all respects.
Of unknown Sicilian origin and no longer planted, Sanguigno Semplice is
believed to be the oldest blood orange variety in Italy.
Sanguinella Negra
See under Spanish Sanguinelli.
Sanguinelli
See under Spanish Sanguinelli.
Sanguinello Comune
Fruit medium-sized, obovoid to oblong; base strongly furrowed and
sometimes with small and very short neck; seeds few or
none. Orange-colored at maturity, washed with
red. Rind medium-thick, moderately tough and adherent, and
moderately to strongly pebbled. Flesh rather deeply red
pigmented at maturity (more so and earlier than rind); juicy; pleasantly
flavored. Midseason in maturity. Stores and ships
moderately well.
Tree of medium vigor and size; productive.
An old Italian variety of unknown origin, Sanguinello Comune has long
been one of the most important blood oranges of Sicily.
From the literature it is not clear whether it is a true horticultural
variety or a group of similar and presumably closely related
clones. It appears not to be a synonym of Sanguinello
Moscato, however, though there are strong resemblances and they are
doubtless closely related.
Sanguinello Moscato (fig. 4-16)
Fruit medium-large, subglobose, round, or oblong; neck strongly
furrowed (more pronounced than Sanguinello Comune); few or no
seeds. Orange-colored with the apical portion strongly
red-blushed. Rind medium-thick, somewhat pebbled, and
moderately adherent. Flesh very juicy; very well flavored;
aromatic; usually well blood-colored. Midseason in maturity
and holds well on tree and ships well.
Tree vigorous, large, symmetrical in form; very productive with most of
the crop borne inside, where it is protected against climatic
vicissitudes and uniformity in pigmentation is favored.
According to Casella (1935a),
this is a subvariety of Sanguinello Comune which is superior in certain
respects that long ago caused it to become the principal variety in the
Mount Etna region of Sicily. Its superiority has given it a
reputation in the export trade as the Paterno orange.
The facts are not known concerning the origin of this old Sicilian
variety but it is one or the most important and probably the most highly
reputed blood orange.
Spanish Sanguinelli (Sanguinelli, Sanguinella Negra) (fig. 4-17)
Fruit said to be similar to Doblefina, but larger, seedier, and often
asymmetrical; persistent style; blood coloration of both rind and flesh
much more intense and constant. External red pigmentation
rarely equalled by other blood oranges and excelled by none, making the
fruit most attractive. Reported to hold on tree longer than
Doblefina and to store and ship fully as well or better. Late
midseason in maturity. Intensity of external pigmentation
and purplish-red color of the chalazal spot (Chapot, 1963e) place this variety in the deep blood group.
Tree small to medium, spineless; foliage light green; productive.
Spanish Sanguinelli is the preferred name to distinguish this new
variety from the Italian light blood group (singular sanguinella, plural sanguinelli).
The variety originated as a limb sport of Doblefina which came to light
about 1950. Its market reception has been excellent and it
seems destined to replace the parent variety and most other Spanish
blood oranges.
Tarocco (Tarocco dal Muso, Tarocco di Francofonte) (fig. 4-18)
Fruit medium-large to large, variable in form from broadly obovate to
globose; commonly with broad, pronounced, and furrowed basal collar; few
or no seeds, the chalazal spots of which are
purplish-red. Yellowish-orange, blushed with red at full
maturity. Rind medium to medium-thick, moderately tightly
adherent, and finely to moderately pebbled. Flesh somewhat
firm but juicy, usually well pigmented; flavor rich and
sprightly. Midseason in maturity (somewhat later than Moro
and Ovaletto). Loses quality if left on tree much past
maturity and drops badly, but ships and stores well.
Tree moderately vigorous, medium in size and irregular in form; foliage
rather open, consisting of highly variable leaves, mainly
oval-elliptical and sharp-pointed. Sensitive to wind and
neglect; only moderately productive.
The name of this comparatively new Italian variety, the English
equivalent of which is the peg-top toy, is said to have come from the
pronounced basal collar that is characteristic of fruits of the original
clone. Scarcely three decades after its discovery, however,
Casella (1935a) distinguished three types or clones, of which
that known as Tarocchino is now considered to be the variety Ovaletto
Sanguigno (Chapot, 1963e).
Tarocco Liscio (Calabrese Sanguigno, Tarocco Ovale)
Fruit medium-large to large, variable in form from oval to obovate;
commonly with broad neck in place of collar; sometimes with small navel;
seeds few or none. Rind medium-thick, somewhat more tightly
adherent than Tarocco, and smooth to very finely
pitted. Internal characteristics and other features similar
to Tarocco proper.
Tree apparently somewhat less vigorous than Tarocco and more sensitive to wind and heat.
That the two clones of Tarocco and Tarocco Liscio may exist as a
chimeric mixture is suggested by Chapot (1963e), who reports that
in Morocco fruits of both types often occur on the same
tree. The clone introduced into California several decades
ago appears to be of the liscio type.
Of unknown origin, but believed to have developed from Sanguinello
Moscato, Tarocco was found by Dinaro Gesualdo in an orchard in the
Carbone area of the Piedegaggi di Carlentini district of Siracusa
Province, Sicily, shortly after the turn of the present century
(Casella, 1935a). Presumably because of its high
quality, attractive appearance, and certainty of red pigmentation, it
spread rapidly to other areas and is now widely planted in Sicily,
generally distributed throughout Italy, and grown to some extent in
Spain and Morocco.
Tarocco is reported
to have exhibited internal pigmentation wherever grown in the
Mediterranean basin and usually some external coloration. Its
behavior in California corresponds with these reports, since some
degree of internal coloration usually develops even in the relatively
cool southern coastal region. This behavior, coupled with the
purplish-red coloration of the chalazal spot, indicates that Tarocco
belongs to the deep blood orange group (Chapot, 1963e).
Tomango
Fruit medium-small to medium, oblong to oval; occasionally with small
navel; seeds few or none. Rind medium-thin, comparatively
smooth; color yellowish-orange at maturity. Flesh tender and
melting, very juicy; flavor excellent. Midseason in maturity.
Tree slow-growing, medium-small, and straggly upright in habit; leaves
large, broadly lanceolate, and suggestive of the Jaffa
variety. Somewhat slow to come into bearing but productive.
In South Africa, where the Tomango variety received its name and has
considerable and increasing importance, it is not grown as a blood
orange, since external pigmentation rarely if ever develops and internal
coloration occurs only in seasons of unusually cold winters, when it is
confined to small red flecks in the flesh. Tomango is
obviously a light blood variety that is grown under conditions
unfavorable for the development of the blood pigmentation.
The origin of this variety is unknown but it has been traced back to
the Watkinson Nurseries of Nelspruit, eastern Transvaal, from whom a
tree was obtained by H. L. Hall of Mataffin (same state) in
1906. It seems likely that it is one of the Mediterranean
light blood varieties.
Tomango is one
of the four midseason varieties recommended for commercial planting in
South Africa (Marloth and Basson, 1955).
Washington Sangre
See under Doublefine Ameliorée.
Washington Sanguine
See under Doublefine Ameliorée.
Minor Pigmented Orange Varieties.—Pigmented orange varieties of regional significance or minor commercial value are presented below.
Chemi
The Chemi is an old Tunisian variety of local importance
only. The fruit is oblong and almost pyriform, because of a
prominent, broad, elevated collar. Both fruit and collar are
sometimes slightly ridged. External pigmentation is light or
lacking, but internal blood coloration is commonly deep and approaches
that of Moro but is less constant. Chapot (1963e) remarks that although the name of Chemi translates as "Syrian" this variety is not now known in the Near East.
Damawi
See under Maourdi.
Demmi
Demmi (meaning blood) is currently the Libyan variety most popular for
export. The fruit is medium to medium small, slightly
oblong-oval, and has a low seed content. The rind is thin and
tough and the flesh is firm but juicy and richly
flavored. Demmi is early midseason in maturity at which stage
both flesh and rind are deep pink. The fruit holds well on
the tree, retains its quality, and stores and ships well.
The tree is moderately vigorous and productive and more resistant to
such unfavorable conditions as desert winds than other
varieties. Of unknown but apparently local origin, several
clones of Demmi are recognized of which the one described here is
preferred. One clone, which should be avoided, apparently
contains an infection that causes marked dwarfing associated with woody
knots on the trunk and larger branches.
Doppio Sanguigno Signorelli
This Italian variety produces an early midseason-ripening and coloring
fruit that is almost seedless and of high quality. The
principal fault of Doppio Sanguigno Signorelli is low productivity.
The writer has not been able to ascertain the current status of this
and minor Italian vanities in this subsection which were described by
Casella (1935a). The fruit of Doppio Sanguigno Signorelli is similar in appearance to Sanguigno Doppio. It
is larger, however, and commonly has a small navel. The rind
is thicker, somewhat more roughly pebbled with some bloom, and more
intensely red-colored at full maturity. The flesh is also
well-colored, juicy, and the flavor sweet and aromatic.
The tree is somewhat lacking in vigor, with numerous pendulous
branchlets, and of low productivity.
Chapot (1963e) believes that this variety probably originated as a bud variation of Sanguigno Doppio.
Iaffaoui Maourdi or Mawardi (Shamouti Maouardi)
This Lebanese variety is a light blood clone of the well-known Shamouti
or Palestine Jaffa and indistinguishable from it except that under
favorable conditions the rind is attractively rose-tinted and the flesh
moderately blood-colored. Chapot (1954) considers the variety
to be of local origin.
Maltaise Boukhobsa
This variety is a Tunisian selection of Maltaise Sanguine which is
indistinguishable except that the fruit is much earlier in maturity and
keeps better, and the leaves are narrower. Chapot (1954)
reports that this very new variety is the earliest to mature of all
blood oranges.
Maouardi or Mawardi Beladi (Damawi)
This light blood Lebanese variety of the beladi type
is also of local importance in Egypt under the name Khalili Ahmer or
Red (Egyptian Blood). Chapot (1954) considers Maouardi to be
of local Lebanese origin.
Ovaletto Sanguigno
Ovaletto Sanguigno produces a very early ripening, lightly pigmented,
nearly seedless, pleasantly flavored fruit. It is a highly
productive variety and the principal fault is poor and uncertain fruit
pigmentation.
The fruit is quite
variable but usually medium to medium-large and oval to oblong with
slightly flattened ends. The rind is medium fine-grained,
moderately thick, and slightly red-tinged at maturity. The
red-streaked flesh is of a pleasant flavor. The fruit, which
stores and ships well, matures shortly after Moro (the earliest blood
orange) and drops badly if held long on the tree.
The tree is vigorous, large, and regularly productive, more so than most other varieties.
According to Casella (1935a), this variety came to light about the same time as Tarocco and in the same area. Chapot (1963e) believes that Tarocchino, described by Casella as a derivative of Tarocco, is identical with Ovaletto Sanguigno.
Saasli
Saasli is a virtually seedless, light blood Lebanese variety of unknown
origin. The fruit is oval in form, with a smooth, thin
rind. The flesh is melting, juicy, and of good
flavor. Under favorable conditions, the rind is highly
pigmented but the flesh poorly colored. The tree is vigorous
but not very productive. Saasli is of minor and local
importance only in Lebanon, and Chapot (1954) considers it of local
origin.
Sanguigno Doppio (Doppio Sanguigno)
Sanguigno Doppio, an Italian variety, produces a midseason, seedy fruit
of rough external texture and mediocre quality. The variety
has not been planted for decades, but still has importance in some of
the older orchards and districts.
The
fruit is medium-small to medium in size, subglobose to spherical,
flattened at both ends, and with a pronounced and furrowed basal
cavity. The rind is medium-thick, very roughly pebbled,
red-splashed and striped at maturity, and puffs badly when
overripe. The flesh is poorly pigmented but pleasantly
flavored. The fruit loses quality rapidly if stored on the
tree and does not store or ship well.
This variety is considered to be one of the oldest blood oranges, but
has never spread much beyond the area where it is presumed to have
originated.
Sanguigno Zuccherino
This Italian variety produces an early, midseason, few-seeded fruit
that is of low quality and keeps and ships poorly. Sanguigno
Zuccherino has not been planted for decades, but still retains local
importance in a few of the older districts of Italy.
The fruit is medium-small, subglobose to round, deeply grooved at the
base and has a small apical basin. The rind is medium in
thickness, soft and not strongly adherent, moderately pebbled, and
pink-blushed at maturity. The flesh is moderately pigmented,
very juicy and sweet, and low in acidity. The fruit is too
flat in taste for most palates.
Shamouti Maourdi
See under Iaffaoui Maourdi.
Vaccaro
The Italian Vaccaro variety produces an attractive, midseason,
few-seeded fruit of good quality. This variety, which has
distinctive tree characteristics, is of limited importance in the
Paterno area.
The fruit is of medium
size, subglobose to spherical, shallow-furrowed at the base, and
slightly flattened at the apex with a faint areolar ring. The
rind is medium-thin, leathery, and tightly adherent. It has a
smooth, glossy surface and is moderately splashed with
pink. The flesh is red-streaked, moderately juicy, and of
agreeable flavor. Seeds are few and small. The
fruit holds well on the tree.
The tree
is somewhat lacking in vigor and has a distinctive growth habit in that
the main branches are horizontal rather than upright and the branchlets
are slender, weak, and pendulous.
Navel Oranges
The most distinctive feature of the navel oranges, in which they differ
from all others, is anatomical in nature and consists of the presence
of the navel—a small and rudimentary secondary fruit embedded in the
apex of the primary fruit. While the tendency to produce
fruits with small navels is exhibited by a number of the mandarins and
some other orange varieties, it is highly variable from season to
season. Only in the navel oranges does this phenomenon occur
regularly. Seedlessness also is characteristic of navel
oranges, resulting from the fact that functional pollen is lacking and
viable ovules are rare.
Closely related to the navels is the seedy double orange (see Tunisian Bourouhaine), in which the secondary fruit is much larger, more deeply embedded, and usually devoid of rind.
Other distinctive characteristics of most navel oranges include a
crispness of flesh texture, ease of peeling and separation of the
segments, and richness of flavor, which under favorable climatic
conditions combine to make navel oranges among the finest of dessert
fruits. These characteristics, added to the deep orange color
navels usually develop, cause them to command a premium in most
markets.
With minor exceptions only,
navel orange trees are less vigorous and more sensitive to unfavorable
conditions of environment or neglect than most other
oranges. This is reflected in greater dwarfing on certain
rootstocks, lower average production in many areas, and a much narrower
range of climatic adaptation. Navel oranges are poorly
adapted to the humid tropics, semitropics, or intense desert heat.
The navel orange was known in the Mediterranean basin several centuries
ago, where it was described and figured by Ferrari (fig. 4-19),
whose famous monograph on the citrus fruits was published in the
seventeenth century in Rome (Ferrari, 1646). Risso and
Poiteau (1818-22) described a Portuguese navel orange
variety. Gonzalez-Sicilia (1963) states that local varieties
of this fruit have long been known in Spain and refers to the preñado
(pregnant) variety described by Giner Alino in 1893. More
recently, a conspectus of citrus varieties in Portugal (Bobone, 1938)
lists and describes two navel oranges—Baia (Bahia of Brazil) and
Comprida. It seems clear, therefore, that navel orange
varieties have long existed in Spain and Portugal and the likelihood
seems good that the Portuguese introduced this fruit into Brazil where
almost certainly the Bahia variety, which has come to be known as
Washington, originated (Dorsett, Shamel, and Popenoe, 1917).
Although importations of navel orange clones from Brazil were made to
Australia as early as 1824 (Bowman, 1955) and to Florida in 1835
(Webber, 1943, p. 531), that which became known as Washington was
received by the U.S. Department of Agriculture in 1870, propagated in
Washington, D.C. under glass, and sent to California and Florida three
years later. The remarkable success of the introduction made
in Riverside, California, led to its rapid commercialization and spread
to other countries.
Navel orange
clones in general, and notably the Washington variety, appear to be
unstable and especially prone to give rise to somatic
mutations. Indeed, with the possible exception of the
so-called Australian variety and
its derivatives, all the navel varieties treated in this subsection are
known or believed to have originated from Washington, nearly all as bud
or limb sports. Moreover, this variety has given rise to
several non-navel clones, among which are the Croc, Marrs, and Trovita varieties.
Primarily because of the Washington and Bahianinha varieties, the navel
oranges are of great commercial importance, ranking second only to the
common sweet oranges. Conservatively estimated, their annual
production in 1965 was in the range of 45 to 50 million 70-pound box
equivalents. The principal navel orange producing countries
are the United States (California), Brazil, Spain, South Africa,
Australia, Morocco, and Algeria.
The
navel oranges are utilized primarily in the fresh form for eating
out-of-hand, in fruit salads, as a dessert fruit, or as fresh
juice. Bitterness often develops when the juice is stored and
is poorly adapted to processing.
Major Navel Orange Varieties.—The ten navel orange varieties of greatest commercial significance are described below.
Atwood (Atwood Early)
The fruit and tree of the Atwood navel orange variety are virtually
indistinguishable from the parent variety, Washington. The
fruit colors slightly earlier and the rind surface appears to be
somewhat smoother, however. While earlier maturity is
suggested by its coloring behavior, the fruit stores on the tree
especially well without appreciable loss of quality. During
the early part of the season, however, its quality is not quite as good
as that of the parent variety.
According to Opitz (1962), Atwood originated as a limb sport in the
orchard of Frank Atwood near Lemon Cove, California, and was first
noticed about 1935. It is considered to be promising in
central California and has been planted to some extent there in recent
years.
Australian
Strictly speaking, this is a group of somewhat similar but inferior
navel orange clones at least one of which was introduced from Australia
into California prior to the successful establishment there of the
Washington navel variety; such an introduction seems also to have
occurred in South Africa. Australian is therefore to be
regarded as the name of a group or type rather than a variety.
In general, the fruits are smaller than Washington, flatter in form,
and sometimes broadly pointed at the apex. The navel is
smaller and more deeply embedded, and the rind is thicker and
rougher. The flesh is softer in texture and commonly juicier
than the Washington, and the season of maturity is considerably later,
the flavor remaining tart until late in the season.
The trees are more vigorous, hardy, larger, and upright-spreading,
rather than drooping as with the Washington. Some clones are
productive but with an alternate-bearing tendency; most, however, are
erratic and unsatisfactory in production and commercially worthless.
The origin of this type of navel orange is obscure, but it is known to
have gone from Brazil to Australia, from whence it was probably taken to
California and South Africa. It may have originated in
Brazil, as did the Washington variety, but it seems more likely to have
been taken to Brazil from Portugal where a navel orange variety has long
existed (Risso and Poiteau, 1818-22). Although perhaps
remote, the possibility clearly exists that this old Portuguese variety
may have given rise to Washington.
Because of its earlier introduction into California and South Africa and
its propagation for some years thereafter, both countries experienced
the problem of eliminating Australian-type clones from use in their
orchards. In California this was long ago accomplished
through care in budwood selection and topgrafting orchard
trees. While no longer propagated in South Africa, there
still remain old orchards of selected Australian-type clones, the
principal two of which are reported to be Company and Pretoria (Marloth and Basson, 1959).
Bahia
See under Washington.
Baiana
See under Washington.
Baianinha Piracicaba (Bahianinha) (fig. 4-20)
The two-word name Baianinha Piracicaba is preferable to distinguish
this important variety from two smaller-fruited Brazilian selections,
Ivers and Thomazzelli.
The fruit is
reported to differ from Washington navel principally as follows: (1) it
averages considerably smaller in size; (2) the shape is slightly more
oval; (3) it has a smaller and closed navel; and (4) the rind is
thinner. The tree is said to be productive but smaller and
less vigorous than the Washington variety.
In California, where this variety has been under observation for only a
few years, the differences between this variety and Washington appear
to be somewhat less than those reported in Brazil.
The presumption is that this variety
originated as a bud mutation from the Washington or Bahia navel
orange. Webber (1943) has presented evidence, however, that
it may not have originated in Brazil, as commonly supposed, since it
appeared in a planting of navel orange trees made at Piracicaba, São
Paulo State, about 1907-08 with budded trees imported from the United
States, presumably Florida. That this variety is somewhat
unstable and has subsequently given rise to other clones is clear from
the literature and the existence of the two smaller-fruited selections
mentioned above.
Primarily because of
its desirable size for export markets, Bahianinha Piracicaba soon
became popular in Brazil and within a few years attained the status of
the major early export variety. It is said to constitute
about a third of the commercial orange acreage of Brazil and is grown
principally in São Paulo State.
Cram
See under Washington.
Dalmau
See under Navelina.
Eddy
See under Washington.
Fisher
See under Washington.
Frost Washington
Frost Washington is the first, and currently much the most important,
nucellar budline of the Washington navel. It was originated
by H. B. Frost, the geneticist and breeder, at the University of
California Citrus Research Center, Riverside, from a controlled cross
made in 1916. It was not released until 1952,
however. Since that time its popularity has increased until
it is now more widely planted in California, Arizona, and Morocco than
any other clonal selection of Washington.
In this connection, mention should be made of the now well-established
fact that Frost already has given rise through bud variation to a new
and much less desirable clone, characterized by a more acid fruit of
later maturity. In comparison to the Frost Washington, the
fruit size and navel opening average smaller, the rind texture is
coarser, and the flesh is more tender (Soost et al., 1961).
Gillette
Fruit large, spherical; navel well developed but not prominent;
seedless. Well-colored. Rind thick and moderately
pebbled. Flesh color, texture, and flavor similar to
Washington. Very early in maturity (about ten days earlier
than Washington) and holds well on the tree.
Tree vigorous and distinctive in appearance; leaves large, thick,
cupped, and somewhat grapefruit-like, clustered toward the tips of erect
branchlets. Fruit said to be less subject to sunburn and
splitting than Washington. Moderately productive.
In comparison with the Washington variety, the fruit of the Gillette is
slightly larger and more spherical. The rind is also
somewhat thicker. The tree is distinctively different in
appearance.
The origin of Gillette is
unknown, but it is presumed to be a limb sport that was accidentally
propagated about 1935 by the Gregg Nursery of Anaheim,
California. It came to light in 1945 when four scattered
trees were found in an orchard owned by the Gillette Brothers at Hemet,
California, which had been planted in 1936 by the Gregg
Nursery. Although not promoted by any nursery company,
plantings of this variety now occur in all the more interior navel
orange sections of California.
Leng (fig. 4-21)
Fruit medium-small to medium in size, globose; navel uniformly small
though well developed; seedless. Color bright
orange. Rind medium-thin to medium and finely
pebbled. Flesh well-colored; texture medium; juicy; flavor
only fair. Very early in maturity (a week or ten days earlier
than Washington), but fruit holds well on tree without loss of quality.
Tree indistinguishable from Washington but fruit more susceptible to
splitting and sometimes undesirably small. A regular but
moderate bearer.
In comparison with
Washington, fruit of the Leng variety reaches maturity slightly earlier,
has a smoother, thinner rind, and is smaller, juicier, and poorer in
flavor.
This Australian variety
originated as a limb sport of Washington in the orchard of A. D. Leng at
Irymple, near Mildura, New South Wales, and first came to notice in
1935. It is currently popular in the Murray River districts
of New South Wales and Victoria and in South Australia.
Navelina (Dalmau)
Fruit medium to medium-large, spherical to obovoid; basal end commonly
strongly furrowed; navel small and not prominent, but opening not
closed; seedless. Color reddish-orange at
maturity. Rind medium-thin and smooth (approaching
Thomson). Flesh color deep; texture medium; rather juicy;
flavor sweet (less sprightly than Washington). Very early in
maturity (fully as early as Thomson and perhaps a little earlier).
Tree lacking in vigor, semi-dwarfed, and small (like Robertson);
characteristic small dark green leaves give a distinctive
appearance. Productive.
In
comparison with Washington, the fruit of the Navelina variety averages a
little smaller and has a much less prominent navel, the rind is
smoother and deeper colored, and maturity is much
earlier. The flavor is not as rich and
sprightly. The tree is notably less vigorous and smaller.
Gonzalez-Sicilia (1963) reports that this variety was received about
1933 from the Citrus Research Center, Riverside, California, under the
name Early Navel (R5, T8, CES 574).9 The
records at the Citrus Research Center show that the variety was
accessioned about 1910 under the name Smith's Early Navel and was
thought to be a budsport of local origin. Under the Spanish
name Navelina, presumably referring to the small tree, this variety is
now available from several nurseries in Spain. It is grown in
Portugal under the name of Dalmau and is under trial in a number of
other Mediterranean countries. Currently, the principal
center of commercial production is reported to be the Sagunto-Castellón
district, north of Valencia, Spain.
Chapot reports that two clones are recognized in
Morocco. That described above is called Dalmau (name of a
Spanish nurseryman). Another, similar in all respects except
that the color of both fruit and leaves is less intense, goes by the
name Navelina.10
Oberholzer (Oberholzer Palmer)
Fruit similar to Washington, but smaller and with less conspicuous
navel. Early in maturity and holds well on tree.
Tree more vigorous than Washington; upright-spreading; outstandingly productive.
This new South African variety should not be confused with the Palmer
Washington, a clonal selection that has been propagated to a small
extent, or with the Ryan, sometimes incorrectly called the Palmer
Nucellar. The variety is recorded as Accession No. 503 of the
Citrus and Subtropical Fruit Research Institute of Nelspruit, eastern
Transvaal, South Africa.
The
possibility would seem to exist that this variety may have originated as
a variation in a nucellar budline, for it came to light about 1950 as
one of four trees sent to Nelspruit by P. C. J. Oberholzer of the
University of Pretoria, who had propagated them with budwood taken from a
group of ten trees whose bud parent was reported to be a Washington
navel seedling of unknown origin.
Oberholzer appears to be promising and has already been planted to a
considerable extent in South Africa, where it is said to be the navel
variety currently most in demand.
Original
See under Washington.
Parent
See under Washington.
Riverside
See under Washington.
Robertson
Fruit virtually indistinguishable from Washington except for
medium-large size, slightly lower quality, and earlier maturity, which
is usually ten days to two weeks. While maturing about the
same time as Thomson, quality is better and fruit is retained much
longer on tree. Because fruit is often borne in tight
clusters, its shape is sometimes slightly distorted and exhibits flat
contact surfaces.
Tree lacking in
vigor (more so than Thomson), small (markedly dwarfed on sour orange
rootstock), heat-resistant, precocious, and very prolific.
The heat resistance and associated high-yielding behavior of the
Robertson navel orange appear to relate to the fact that, although it
blossoms at about the same time as other varieties the young fruits
develop more rapidly and pass through the fruit-setting phase
earlier. The fruits thus escape the severe dropping
associated with the heat and dryness normally characteristic of the
later fruit-setting period of other varieties (Coit and Hodgson, 1919).
Robertson originated as a limb sport in an old Washington navel tree in
an orchard near Redlands, California, where it was found by Roy
Robertson in 1925. It was patented (U.S. Plant Patent No.
126) by Armstrong Nurseries of Ontario, California, and introducer to
the trade in 1936. Although planted and topworked to some
extent, it has not become commercially important in California or
Arizona, nor apparently elsewhere. However, because of its
small tree size and early and high productivity, it is popular as a
dooryard or container-grown patio tree.
Tibbets
See under Washington.
Thomson (Thomson Improved) (fig. 4-22)
Fruit medium-large, globose to slightly obovate or ellipsoid;
occasionally with collar and commonly with two or three relatively deep
and long radial basal furrows; apex usually protruded or broadly nippled
or with large open navel; seedless. Less well-colored than
Washington. Rind medium-thin and surface smooth and glossy
though finely pitted. Flesh well-colored with firm texture;
medium juice content; flavor good. Holds on the tree poorly
with rapid loss in quality. Very early in maturity (10 days
or more in advance of Washington).
Tree less vigorous and more compact than Washington and commonly
semi-dwarfed; also less cold- and heat-resistant. Clone
unstable, very likely chimeric in constitution, and exhibits tendency
toward reversion.
The Thomson variety
originated as a limb sport of Washington in Duarte, California, and was
named and introduced by the owner, A. C. Thomson, about
1891. Because of the earliness and attractive appearance of
the fruit, it was extensively planted for some years and introduced to
other navel orange-producing countries such as Algeria, Morocco, Chile,
and Australia. Within a few years, however, its faults became
so evident that planting was discontinued and most of the California
acreage was converted or removed. So far as can be
determined, this has been its history elsewhere, with the possible
exception of Chile. Except for earliness of maturity, it is
inferior to the parent variety in all respects.
Dungan Thomson is
the only selection of Thomson currently propagated in
California. The tree or trees employed are in an old and
outstanding orchard of this variety at Exeter, the present owner of
which is Jack Dungan of that locality. Dungan Thomson has
come into prominence recently because of renewed interest in the
planting of very early maturing varieties in the San Joaquin Valley.
Warren
See under Washington below.
Washington (Bahia, Riverside, Baia, Baiana) (fig. 4-23)
Fruit large, spherical to obovoid or ellipsoid; base sometimes slightly
collared; apex often slightly protruded or broadly nippled; navel
medium to large and sometimes protruding navel;
seedless. Especially well-colored (deep
orange). Rind medium-thick, somewhat tender; surface coarsely
pitted and moderately pebbled. Flesh color deep; texture
firm; moderately juicy; flavor rich. Fruit holds on tree and
stores and ships relatively well, but processes poorly. Early
in maturity.
Tree round-topped,
somewhat drooping, and medium in size and vigor. Sensitive to
heat and aridity during bloom and fruit-setting, and hence restricted
in range of climatic adaptation. Anthers cream-colored, for
they are devoid of pollen.
The origin
of the Washington or Bahia variety is not known but, after a study at
first hand, Dorsett, Shamel, and Popenoe (1917) of the U.S. Department
of Agriculture concluded that it was probably a limb sport that was
found in a tree of the Selecta variety near Bahia, Brazil, and first
propagated some time between 1810 and 1820. In the opinion of
the writer, it is more likely that the parent variety was the
Portuguese navel (Umbigo) orange described by Risso and Poiteau (1818-22) and that it originated somewhat earlier.
The marked superiority of the new variety was noted by travelers and
visitors and led to its introduction into Australia in 1824 and Florida
in 1835. It is known that trees were sent from Australia to
California as early as 1870 (Coit, 1915, p. 16). The
introduction that led to adoption of the name Washington and to its
commercialization in California and most other countries where it is now
grown, however, occurred in 1870 when twelve budded trees were received
from Bahia by William 0. Saunders, superintendent of gardens and
grounds for the U.S. Department of Agriculture in
Washington. These were planted in a greenhouse and
immediately propagated for distribution. Several years later
trees were sent to a number of persons in California and
Florida. Among those who received trees were L. C. Tibbets of
Riverside, Alexander Craw of San Diego, and Edwin Kimball of Hayward
(Butterfield, 1963, p. 34).
It was the Tibbets
planting, however, that resulted in the name Washington being attached
to this variety and brought it into prominence. It is
believed that Tibbets received and planted three trees in his dooryard,
located near the present junction of Central and Palm Avenues, two of
which survived and became sources of budwood a few years
later. In 1903, one of these was transplanted to a location
in front of the Glenwood Hotel (now the Mission Inn) where it survived
only a few years. At about the same time, the other tree
became the property of the City of Riverside and was removed to its
present location at the head of Magnolia Avenue, where it still exists,
although in a condition of decline from which it seems unlikely to
recover.
Planted in March, 1874
(Mills, 1943), the Tibbets trees came into bearing early and the fruit
soon attracted local attention. Exhibited at a citrus fair in
Riverside on January 22, 1879, by the Southern California Horticultural
Society, it was awarded first prize over other navel oranges, all of
which were from stock previously imported from Australia. The
Washington was so superior that enterprising nurserymen and growers
propagated it extensively and within a decade or two it became the
leading variety, a position it held for many years. Thomas W.
Cover, a local nurseryman and grower, who also exhibited it at the
above-mentioned fair, is credited with having first propagated the
Washington variety. From California it early spread to other
parts of the citricultural world and soon became a major variety, now
second only to Valencia.
As to whom
credit is due for calling the Bahia navel orange to Mr. Saunder's
attention and providing the budded trees received by him in 1870, the
facts are somewhat uncertain. Coit (1915, p. 17) states that a
woman missionary stationed at Bahia was responsible, but Webber (1943,
p. 531) credits F. I. C. Schneider, whom be states was the first
Presbyterian missionary sent to Bahia. It seems likely that
both statements are correct and that the transaction involved both Mrs.
Schneider and her husband, for in later correspondence Mr. Saunders
stated that his correspondent was a woman.
Although early introduced and planted extensively in Florida, this
variety has proven to have only limited commercial value
there. It tends to produce poorly and the fruit is generally
large, coarse-textured, and of poor quality. It is clearly
not well adapted to hot, semitropical climates. There are
several other navel varieties or local origin, however, that do much
better in Florida and have been planted commercially in recent years,
among which are Summerfield, Glen, and Dream. So far as can be ascertained these are all seedling or mutant clones of obscure.
Presumably having originated as a limb sport, Washington has exhibited a
remarkable degree of somatic instability, giving rise by bud mutation
to numerous clonal varieties and many chimeras. That earliest
recognized in California is Australian,
which may have originated in Australia but more likely in
Brazil. It is more vigorous but commercially nearly
worthless. Some of the earlier introductions into Florida
seem likely to have been mutant clones. The principal
varieties known to have originated in California as limb sports include
Thomson, Carter, Robertson, Atwood and Gillette. Of little or
no importance are Navelencia, Nugget, Buckeye, Riverside Early,
Surprise, Yellow, and Summernavel. Several have been reported
from South Africa and Australia.
There are also a number of named clonal selections and at least one
nucellar clonal budline currently under propagation.
Although a number of outstanding trees have been selected and
registered for use in propagation, three have been of principal interest
in recent years, namely Eddy, Parent (Original, Tibbets), and
Warren. Eddy was named for the owner of a superior orchard in
Arlington, California, the clone of which traces back to an outstanding
tree at East Highlands. Warren goes back to an outstanding
tree near Glendora, California, that was selected by C. M. Warren,
long-time prominent citrus nurseryman. Parent, as the name
and synonyms indicate, is the last remaining tree of the Tibbets
introduction from Washington, D.C., and hence the original clone to
which this variety traces in California. Unfortunately, for
some years past it has been declining in vigor and in 1967 seemed
unlikely to survive much longer. Other selections that have
been used somewhat include Cram and Fisher.
Minor Navel Orange Varieties.—Navel orange varieties of limited commercial importance or declining popularity are presented below.
Baddaford
See under Flannagan.
Bellamy
Fruit large, shape varying from oblate to obovate; navel small or
lacking, rind of medium thickness and texture. Well-colored,
juicy, and of good flavor.
Tree vigorous, upright, moderately thorny, and productive.
The Bellamy variety of Australia originated as a chance seedling,
presumably of the Washington navel, at Ourimbah, New South Wales, and
was first planted commercially by a Mr. Bellamy of that community in
about 1930. It is recommended only for conditions not
sufficiently favorable for Washington and seems not likely to achieve
much importance.
Bourouhaine (Orange Double, Orange du Bey)
Fruit medium-sized, oblate to subglobose; apex flattened or slight
depressed and large; externally inconspicuous and deeply embedded navel
which usually is completely without vestiges of peel and hence in
cross-section gives the appearance of a double fruit. Seedy
when cross-pollination available, but seedless when not as viable pollen
is not produced. Juicy and flavor good. Early in
maturity but does not hold well on the tree.
This is an old and highly distinctive variety in Tunisia that is
considered to be of local origin. It is believed to have
given rise to the similar but acidless Bourouhaine Meski variety.
Buckeye (Golden Buckeye)
Fruit oblong to ellipsoid; apex nipple-like, containing a closed navel;
rind very smooth, thin, and leathery. Yellowish-orange
colored, with occasional narrow orange streaks or
ribs. Matures considerably earlier than Washington.
Tree slow-growing, small, and weak.
Buckeye is reported to have originated in California as a limb sport of
Washington. It was introduced in 1903 by the R. M. Teague
Nurseries of San Dimas. This weak-growing and chimeric
variety has never attained much commercial importance.
Carter
Both the tree and fruit of this California variety are so similar to
Washington that they are indistinguishable. Grown under the
same conditions, however, the rind of Carter appears to be somewhat
smoother and thinner, the flesh texture a little less firm and juicier,
and the flavor somewhat sweeter (less tart). Carter is also
slightly earlier in maturity.
Presumed
to be a bud variation of unknown origin, a number of old trees of this
variety were noted about 1925 in the A. N. Carter orchard at Sierra
Madre, California. The variety was introduced by the
Armstrong Nurseries of Ontario, California in 1928 and recommended for
home planting. It is still in demand in California and has
been planted to some extent elsewhere.
Company
Fruit medium-small to medium, subglobose to oblate; basal end deeply
furrowed; apical end drawn out to a broad point in which a prominent
navel is embedded. Flesh melting, juicy; flavor good, but
acid until late in the season. Midseason in maturity (much
later than Washington).
Tree vigorous, large, and productive, but with tendency to alternate bearing.
The Company variety is a South African selection of the so-called
Australian navel made in one of the orchards of the Webster Estates at
White River in 1913. While this variety has not been planted
for many years, old orchards of it still exist in the White River area.
Dream
Fruit medium-sized, subglobose to spherical; navel medium to
medium-large; rind smooth, well-colored, and of medium
thickness. Flesh texture moderately soft; flavor rich and
sweet (less acid than most navels). Early in maturity and in
Florida holds on tree better than most navels without loss of internal
quality.
This Florida variety was
found in 1939 by D. J. Nicholson of Orlando as a budded tree in an old
orchard of mixed varieties near Sanford. It was named,
patented (U.S. Plant Patent No. 625), and released in 1944.
Dungan
See under Thomson.
Flannagan (Baddaford)
This South African selection is from an individual tree in the
Flannagan orchard at Baddaford, Fort Beaufort, eastern Cape Province,
planted about 1903, that was much used in the early period of the
industry. There is reason for believing that it was
propagated from a Bahia navel tree imported from Brazil and presented to
Mr. Flannagan in 1905 by C. P. Lounsbury, government
entomologist. Flannagan is typical of Washington navel in all
respects except that the twig growth is perhaps a little finer and
thinner.
A few commercial orchards
still exist in the Rustenburg area but new plantings have not been made
for many years.
Glen (Glen Improved)
Glen is similar to the Washington navel but reported to bear more
heavily and consistently under similar conditions in Florida.
Found as a group of trees of similar behavior in a Washington navel
orchard of a W. C. Roe of Winter Haven, Florida, this variety is thought
to have originated as an unrecognized limb sport. The
possibility would seem to exist, however, that it represents a clonal
selection. It was named and introduced in 1934 by the Glen
St. Mary Nurseries of Glen St. Mary, Florida.
Golden Buckeye
See under Buckeye.
Greathead
This South African clonal selection was made from one of five trees in
the 16-year-old Washington navel orchard of P. Greathead near Nelspruit,
eastern Cape Province, that were provided by the U.S. Department of
Agriculture in 1919. The tree selected is said to have been
received under the label Shamel. It is typical of Washington
navel in all respects and has been widely used in South Africa.
Navelate (Navel Tardia)
Fruit similar to Washington but somewhat paler in color; navel less
prominent and more commonly closed; rind thinner and more leathery;
flesh less firm and juicier; flavor less sprightly. Matures
two to three weeks later than Washington and holds on tree considerably
better and later without loss of quality.
Tree somewhat more vigorous and productive.
According to Gonzalez-Sicilia, this Spanish variety originated as a
limb sport in a Washington navel orchard planted in 1930 in the Vinaroz
district of Castellón de la Plana Province. It was discovered
in 1948 by D. Adrian Gil, nurseryman of Alcanar, Taragona Province, who
propagated it in 1952 and released it in 1957. In view of
its many desirable features, Navelate is considered to be highly
promising.11 Cliapot,
however, questions its value and reports that in Morocco the fruit is
less juicy than Washington and is not signficantly later in maturity.12
Navelencia
Fruit paler in color than Washington; rind much smoother (similar to
Thomson), and slightly tougher; navel somewhat prominent but usually
closed. Maturity slightly earlier than Washington, but later
than Thomson. Flesh texture firm, but juicier than Thomson;
flavor as good or better. Fruit holds better on tree than
Thomson.
Tree less vigorous than Washington.
This variety originated in the orchard of A. C. Thomson at Duarte,
California, and was introduced in 1903 by the R. M. Teague Nurseries of
San Dimas. Although popular for a while, Navelencia has not
been planted for many years.
Navel Tardia
See under Navelate.
Newhall
Fruit slightly smaller than Washington, oblong to ellipsoid; color
reddish-orange (deeper than Washington); flavor excellent; maturity
earlier than Washington.
Tree somewhat less vigorous than Washington and leaves slightly darker green.
This new California variety is said to have originated as a limb sport
in the Duarte area that was propagated by Paul Hackney of the Newhall
Land and Water Company of Piru and came to prominence in their variety
collection. Because of its attractive appearance and early
maturity, Newhall is currently under trial in several districts of
California.
Nugget (Golden Nugget)
Fruit medium-large, oblong; naval medium small but open; rind
relatively smooth and pale yellowish-orange; flesh crisp and moderately
juicy; pronounced tendency to splitting. Early in maturity.
Tree weak-growing, small, and drooping.
A limb sport discovered by J. P. Engelhart of Glendora and introduced
by the San Dimas Nursery Company in 1893, this Californian variety never
attained commercial importance.
Orange Double
See under Bourouhaine.
Orange du Bey
See under Bourouhaine.
Pretoria
Fruit medium-small to medium, subglobose to almost oblate, navel small
and inconspicuous. Flesh juicy, melting, and acid in flavor
until late in the season. Early midseason in maturity (much
later than Washington).
Tree vigorous, large, and productive, but with tendency to alternate bearing.
Pretoria is a South African selection of the so-called Australian navel
type made in 1933 from a distinctive high-yielding tree in the orchard
of a Mr. Van Skalkwyk in the Pretoria District.
Riverside (Riverside Early)
Both the tree and fruit of this Californian variety are very similar to
the Washington navel but the rind surface is a little smoother and the
percentage of closed navels is higher. The season of maturity
is about the same and possibly slightly earlier for Riverside.
The origin of this variety is obscure, but it is known that it was sent
from California to F. W. Savage at Eustis, Florida, in
1895. It has never achieved commercial importance in either
state. In a small trial in the Imperial Valley of California
some years ago, however, its yield was superior to that of other navel
orange varieties including Washington, which suggests June drop
resistance.
Rustenburg
Fruit similar to Washington navel, but more globose; rind thinner,
firmer, and smoother; navel less conspicuous. Slightly later
maturity and of good quality.
Tree not distinctive and bears well.
This South African variety originated in a group of five variant trees
in the orchard of A. P. M. Robinson, Heks Kranz, Rustenburg, and is
doubtless a budsport of local origin. It was first propagated
in 1944 and still has limited commercial importance in the Rustenburg
area.
Summerfield
Fruit similar to Washington navel but somewhat smaller, with smaller
navel. Flavor sweet but not rich because of low acidity which
results in early maturity.
Tree reported to be regularly productive in Florida.
The origin of this Florida variety has been traced to a "selected tree
or trees" found in 1928 by W. J. Lyles in an old orchard, locally called
the Wild Grove near Weirsdale. The variety was released by
the Summerfield Nursery Company, Weirsdale, about 1931. It is
currently the navel orange variety most widely planted in Florida.
Summernavel (Workman)
Fruit similar to Washington, but rind thicker and rougher in texture;
colors and matures considerably later. Holds on tree
especially well with little loss in internal quality.
Tree more vigorous, low and spreading; leaves larger than Washington;
twig bark distinctively russet-brown.
A
budsport discovered about 1934 in the orchard of J. A. Workman at
Riverside, California, this variety was named, patented (U.S. Plant
Patent No. 347), and introduced by the Armstrong Nurseries of Ontario in
1942. Summernavel is recommended for home planting and has
not achieved commercial importance.
Surprise
Fruit very similar to Washington, but averages slightly smaller; rind
somewhat smoother; navel for most part closed. Slightly later
in maturity.
Tree perhaps slightly less vigorous than Washington.
This comparatively old variety of unknown Californian origin was named
and introduced by E. S. Hubbard of Federal Point, Florida, who
discovered it in a lot of King mandarin trees propagated from budwood
obtained from California after the Florida freeze of
1894-95. While it fruited much better than Washington, it was
never extensively planted in Florida and is virtually unknown in
California. In the opinion of the writer, the possibility
exists that Surprise and Riverside are the same.
Suzuki
Fruit similar to Washington navel in size; navel smaller; rind thinner,
smoother, and somewhat deeper color; flavor less
acid. Slightly earlier in maturity but stores well.
Tree a prolific bearer.
This Japanese variety was first noted about 1935 as a limb sport in a
20-year-old tree in the orchard of M. Suzuki, in Shizuoka Prefecture,
and was released for propagation in 1949 and registered in
1963. Because it is prolific, very early maturing, and of
excellent quality, Suzuki is considered to be very promising.
Suzuki is one of a number of mutant varieties that Washington navel has
given rise to in Japan. This variety, Tange, and Ukumori are
considered the most promising, although navel plantings are currently
of minor importance in Japan (approximately 1,750 acres in 1961).13
Tange
Fruit similar to Washington, but somewhat smaller; navel much
smaller. Flavor as good or better, maturity season about the
same, and keeping quality somewhat better.
Tree notably vigorous; flowers very large; leaves broad and thick, with
strongly winged petioles; prolific.
This Japanese variety was found in 1946 as a limb sport in the
25-year-old orchard of H. Tange, in Hiroshima Prefecture, and registered
in 1961. Tange is considered to be one of the most promising
navel varieties in Japan.
Texas
Both the tree and fruit of this variety are similar to the Washington
navel, but the fruit of Texas is somewhat smaller, seedier, and
exhibits a higher percentage of open navels. When grown in
California, the Texas variety has proven less fruitful.
Texas was introduced into the United States from Brazil by the U.S.
Department of Agriculture in 1916 (Dorset, Shamel, and Popenoe, 1917)
and first propagated in 1924 at the Weslaco Substation of the Texas
Agricultural Experiment Station. Early trials there suggested
the possibility of greater productivity than Washington and a
superiority in fruit quality. Similar comparisons at the
Citrus Research Center in Riverside, California, and at Indio,
California, failed to confirm such results as did later trials in Texas.
Ukumori
Fruit similar to Washington but larger (sometimes much larger); rind
thicker and rougher; surface texture coarse; flavor less attractive.
Tree similar to Washington, but more vigorous and productive.
This Japanese variety originated as a limb sport found in 1938 in the
orchard of M. Ukumori, in Ehime Prefecture, and was registered in
1950. Because of its fruitfulness and large size, it has been
planted to some extent in Japan, but the inferior quality of the fruit
seems likely to lead to its replacement with better varieties.
Watt (Watt's Early)
Similar to Washington but fruit smaller; navel less conspicuous; colors
and ripens earlier. Fruit quality excellent.
Tree lacking in vigor, small and compact, but precocious and productive.
This South African variety originated as a limb sport in a Washington
navel tree on the property of a Mr. Glegg at Kirkwood, eastern Cape
Province, and was noted and propagated by a man named Watt about
1945. It is currently of little importance and little
propagated.
Workmen
See under Summernavel.
Fruits Resembling the Sweet Orange
Although some fruits commonly assumed to be natural tangors
(mandarin-orange hybrids) exhibit various characters of the sweet
orange—adherent rind, solid axis, white cotyledons, and form of the
petiole wings—and there are also some that are subglobose in shape and
bland in flavor, the writer is unacquainted with any of which the
composite picture more resembles the sweet orange than the mandarin and
would hence justify their inclusion in a sweet-orange-like
group. This is also true of all synthetic tangors known to
him.
While the Temple, Murcott, and
King varieties are usually called oranges in Florida, and the new hybrid
Page variety was introduced as an orange, King is regarded in this
treatment as a member of the Citrus nobilis mandarin group, Temple is provisionally classed as a natural tangor and the others are included in the Citrus reticulata mandarin group.
SOUR OR BITTER ORANGES (CITRUS AURANTIUM L.)
Like most of the other citrus fruits of commercial importance, the
sour, bitter or Seville orange is considered to have originated in the
region of northeastern India and adjoining portions of China and
Burma. Spreading northward to Japan and westward through
India to the Mediterranean basin, it finally reached Europe sometime
around the Christian era. The sour orange was among the first
citrus to be taken to the New World. In such climatically
favorable portions of the New World as Florida and Paraguay it escaped
from cultivation and became feral. It is the naranja agria or amarga of Spain, melangolo or arancio amaro of Italy, bigarade or orange amére of France, khuskhash of Israel, khatta of West Pakistan and parts of India, and daidai of Japan.
While
the sour and sweet oranges have close resemblances there are important
differences which clearly justify their separation into different
species. The sour orange leaf is somewhat darker in color and
more taper-pointed and the petiole is longer and more broadly
winged. The fruit is usually flatter and more deeply colored
and the rind thicker and more loosely adherent. The rind
surface is generally rougher and is minutely pitted with sunken oil
glands. The core is normally hollow and the flavor sour with
pronounced bitterness in both carpellary membranes and
albedo. Most distinctive and easily recognizable differences
relate to the odor of the oils in the leaves and rind. In the
sour orange the leaf oil is agreeable and distinctive, whereas in the
sweet orange it is merely pleasant. Sour orange rind oil is
strong and somewhat disagreeable in contrast with the sweet and pleasant
odor of sweet orange rind oil. Moreover, the chalazal spot
is purple-tinted in the sour orange, reddish-brown in the sweet oranges
in general, red in the deeply pigmented blood oranges, and cream-colored
in the sugar or acidless oranges (Chapot and Praloran, 1955).
In comparison with the sweet orange, the sour orange tree is more
upright and thorny and much more resistant to such unfavorable
environmental conditions as frost, excess soil moisture, and
neglect. However, the sour orange does not attain as large size as the sweet orange. It is also much more resistant to the widespread gummosis (mal di gomma)
disease. In addition, it is susceptible to verrucosis (scab)
and markedly intolerant to the tristeza virus when used as a rootstock,
while the sweet orange is highly resistant to both diseases.
The fruit is too sour and bitter to be acceptable to most palates,
although it can be used to make a distinctive and refreshing
drink. Its principal use, however, is in the preparation of a
distinctive marmalade, much in demand and appreciated in Europe and
especially so in Great Britain, for which sweet orange marmalade is not
an acceptable substitute. To meet this demand, sour oranges
are grown to a limited extent in most of the Mediterranean
countries. The principal producing area, however, centers
around Seville in southern Spain, where commercial plantings are
currently reported at approximately 4,000 acres. Great
Britain comprises the principal sour orange market. Other
products obtained or made from the fruits include rind oil and the
liqueurs curaçao and Cointreau.
Oil of
petit grain is distilled from the leaves and young shoots and oil of
neroli from the flowers. For these products, however, which
are much used in perfumery, special varieties selected primarily for
flower production constitute the principal source of
production. A byproduct of this process is orange
flower-water, also used in perfumery, for flavoring cakes, and for
medicinal purposes.
The importance of
the sour orange in the citricultural world, however, arises from its use
as a rootstock. Because of its marked resistance to the
soil-inhabiting fungi principally involved in the gummosis and foot rot (mal di gomma) diseases,
a century or more ago it became the leading rootstock. While
its use as a rootstock has declined greatly in recent years because of
marked intolerance to the tristeza virus disease, and it now seems
destined to be abandoned for that purpose, sour orange remains a major
rootstock in the Mediterranean basin and some other areas.
Because of the attractive appearance of both tree and fruit and their
hardiness and resistance to unfavorable conditions in general, the sour
oranges are also useful as ornamentals.
Three natural groups are distinguishable in the sour oranges, namely
the common bitter orange, bittersweet orange, and the variant bitter
oranges.
Common Bitter or Sour Orange
This is the ordinary bitter orange (fig. 4-24) so extensively employed as a rootstock and grown in Spain and elsewhere as a marmalade fruit.
The principal marmalade variety in Spain (Gonzalez-Sicilia, 1963) is
Sevillano (Agrio de Espana, Real), which is said to consist of a group of selected clones characterized by victor, comparative freedom from thorns, and productivity.
In California, comparison of rootstock clones from many parts of the
citricultural world with some of local origin has revealed a
considerable range of variation in both tree and fruit characters but
none has proved to be outstandingly superior though several have been
named.
Bittersweet Orange
The bittersweet orange group, which contains at least two varieties,
may be regarded as a subgroup of the common bitter orange, from which it
differs mainly in lower acidity and better flavor.
Formerly thought to be a hybrid of the sweet and sour oranges, the
weight of evidence suggests that the bittersweet orange originated as a
mutation from the latter. It appears to be identical with thc
fruit described by Risso and Poiteau (1818-22, p. 101) as the
sweet-fruited bitter orange of the Mediterranean basin. It
seems likely that the Spanish took this orange to both Florida and South
America, for it was early found in the former and occurs extensively in
Paraguay where it comprises an important source of oil of petit grain.
Minor differences that characterize most of the bittersweet oranges
include somewhat denser and more compact habit of growth, broader and
less taper-pointed leaves, and paler-colored fruit of slightly smaller
size and smoother rind texture.
Two
named varieties, both of which doubtless consist of more than one clone,
are Bittersweet of Florida and Paraguay (Apepu). They are so
similar as to be scarcely distinguishable.
Variant Bitter Oranges
In contrast with the high degree of similarity that characterizes the
common and bittersweet sour oranges, the variant bitter oranges exhibit a
remarkable degree of diversity of forms and characters. All
are less vigorous than the common and bittersweet oranges—some
strikingly so—and, in general, they have broad, spreading tops, few or
no thorns, smaller and less wing-margined leaves, and smaller and
flatter fruits containing fewer seeds. A few exhibit
teratological characters of a brachytic nature. Variant
bitter oranges are grown principally for perfumery purposes and as
ornamentals.
Perfumery Varieties (Bouquetiers).—While
extensive use is made in Italy and Paraguay (and to some extent in
Spain and North Africa) of the flowers of the common bitter orange for
production of oil of neroli and the byproduct orange flower-water,
special perfumery varieties grown solely or primarily for the flowers
are employed in the French Riviera, the traditional perfumery center of
the Mediterranean basin, and also in North Africa. For the
most part these varieties are characterized by small tree size, freedom
from thorns, and profuse flowering. The three varieties most
widely grown appear to be the following:
Bouquet (Bouquet de Fleurs) (fig. 4-25)
This heavy-flowering variety constitutes an attractive ornamental in
California, lending itself especially well to use as a hedge
plant. In California, it is characterized by small tree size
with a spreading top consisting of thornless branchlets with short
internodes (brachytic in nature) and dense clustered
foliage. The leaves are small, oval, and round or
blunt-pointed with short wingless petioles. The fruits are
small, somewhat oblate, moderately pebbled and well-colored, with
medium-thick rind, solid axis, and few seeds. Chapot (1964a) considers this to be the old most Bigaradier Riche Dépouille of Risso and Poiteau (1818).
Bouquetier a Grandes Fleurs (Bouquetier à Peau Epaisse)
This variety is much the most important of the perfumery varieties (Chapot, 1946b)
and is characterized by very large, single flowers and large round
fruits with very thick and hard rinds. The tree is small and
spineless and the leaves are medium-sized, broad and blunt, or
round-pointed. The fruit makes excellent confections.
Bouquetier de Nice a Fleurs Doubles (Bouquetier de Nice à Fruits Plats, Bouquetier de Nice)
This variety is the Bigaradier à Fruit Fetifere of
Risso and Poiteau (1818-22). The tree is vigorous and
upright-growing and the flowers are double with a very large pistil,
which usually gives rise to a flat fruit of medium size that is also
double, since it contains a well-developed secondary fruit deeply
embedded inside the primary fruit. The leaves are very large
and broad but slightly taper-pointed.
Ornamental Varieties.—Although
the perfumery varieties are also used as ornamentals, there are other
variant or aberrant forms of the bitter orange that are grown only as
ornamentals. Among these are the following:
Abers Narrow Leaf (fig. 4-26)
This is an extremely narrow-leafed form, the tree of which is small and
drooping in habit and the fruit of which is typical for bitter orange
with thc exception that the calyx is fleshy. The presumption
is that Abers Narrow Leaf originated in Florida, where it received its
name, though it may have been introduced there. From the
literature, it appears to be very similar to, if not identical with, the
Granito variety (salicifolia) of Trabut as described in Algeria.
Kabusu (Kabusudaidai)
This variety is reported to be virtually indistinguishable from
Zadaidai except that the calyx is normal and not large, fleshy, and
distinctive.
Both Zadaidai and Kabusu
are grown primarily as ornamentals in Japan and the fruits are used for
decorative purposes and in the preparation of marmalade and vinegar.
Kikudaidai (Citrus canaliculata Y. Tanaka)
The Kikudaidai variety is an attractive, somewhat dwarfed ornamental
with fruits that have a solid core and are medium-small, subglobose to
oblate, yellowish-orange, and characteristically deeply, longitudinally
grooved. The origin of this ornamental is unknown.
Panaché
See under Variegated below.
Variegated (Panaché)
While variegation is not uncommon in citrus fruits, clones are
comparatively rare in which it is exhibited in both foliage and fruits
combined with good vigor and attractive appearance. A bitter
orange clone which meets these requirements occurred about 1920 as a
seedling in a nursery of the Citrus Research Center, Riverside,
California. Since Variegated reproduces from seed to a
remarkable degree, it is believed to have originated as a nucellar
chimera.
It is characterized by
vigor, though not as great as the seed parent, and the variegation is
manifested mainly in the fruits, a high percentage of which are
beautifully striped with yellow and deep orange. It has been
propagated under the name Variegated Sour.
That one or more clones of similar appearance are known in the French
Riviera is clear from literature references to the Bigaradier Panaché.
Willowleaf
As the name indicates, this is a willow-leafed form of
ornamental. The tree is moderately dwarfed, of highly
symmetrical round-topped form, with dense compact foliage consisting of
small, narrow, sharp-pointed, yellowish-green leaves. The
fruits are small, round to pyriform, yellowish-orange and with only
juiceless flesh.
Only one clone of
Willowleaf has been noted in California and its origin and history are
unknown (Bitters, 1957), although it is believed to have been introduced
under the botanical variety name salicifolia. It is markedly different from Abers which has sometimes called Willowleaf.
Zadaidai (fig. 4-27)
The Zadaidai is a well-known variety in Japan. The tree is
somewhat lacking in vigor, usually dwarfed, round-topped, and nearly
thornless, but otherwise similar to the common bitter orange except that
the leaves are slightly smaller, with petioles more narrowly
winged. The fruit differs only in the fact that the calyx is
unusually large, well developed, and very thick and fleshy, a character
occasionally found in other citrus fruits.
Fruits Resembling the Sour Orange.—In parts of the Orient, notably Japan, there are citrus fruits
commonly referred to as species which appear to be natural hybrids of
sour orange parentage. Those of commercial importance that
resemble the sour orange for the most part also exhibit mandarin
characters. The principal fruits among these are the
following:
Kitchli (Vadlapudi and Guntur Sour Orange) [Citrus maderaspatana Tan.] (fig. 4-28)
Fruit medium-sized, depressed globose to broadly obovoid; sometimes
slightly necked; color yellowish-orange; seedy; rind rough, somewhat
warty, and of medium thickness and adherence. Core
semi-hollow at maturity. Flesh pale orange-colored; flavor
pleasant at full maturity, with slightly bitter aftertaste and musky
aroma. Prior to maturity flesh sharply
acid. Cotyledons light green.
An old Indian fruit of unknown origin, the Kitchli somewhat resembles
the bittersweet orange though it is smaller, flatter, and rougher in
surface texture. It is of commercial importance in South
India, principally in the Guntur district, where it is grown on a
somewhat extensive scale. Several clones are recognized, but
only that of mildest flavor is propagated commercially.
Nanshôdaidai [C. taiwanica Tan. & Shimada]
Fruit medium-large, obovate; broadly necked and narrowly collared;
seedy. Rind medium-thick but easily peeled; somewhat pebbled;
prominent sunken oil glands; color lemon-yellow. Sections 10
to 12 and axis open. Flesh color dull yellow; juicy; acid
flavor with bitter aftertaste. Seeds large, slimy, with
wrinkled seed coat, and polyembryonic.
Tree vigorous, upright-spreading, and very thorny. Foliage
consists of medium-large, somewhat slender, light green, sharp-pointed,
strongly winged leaves, the oil of which is suggestive of bitter orange.
Thought to have originated in the Nanshô district of Taiwan (Formosa),
where it has no economic importance, the Nanshôdaidai is included here
because of its promise as a substitute for sour orange rootstock in
California.
Naruto (Narutomikan) [C. medioglobosa Tan.]
Fruit medium-sized, subglobose to slightly oblong; orange-colored;
seedy; rind smooth but rather thick; easily removed rind and open
core. Flesh color yellowish-orange; tender and juicy; flavor
good. Very late in maturity.
A very old Japanese fruit of unknown origin, the Naruto is still grown
but no longer propagated. It is confined to Awaji Island of
Hyogo Prefecture.
Sanbô (Sanbôkan) [C. sulcata Takahashi]
Fruit medium-sized and obovoid; collar or neck prominent; rind
medium-thick, yellow, coarsely pebbled, somewhat bumpy, and easily
removed, with tendency to re-green. Flesh moderately juicy
and flavor good. Late maturity.
Sanbô is an old Japanese fruit of unknown origin, first described in
1848, that is still popular and grown mainly in Wakayama Prefecture.
Myrtle-leaf Orange (Citrus myrtifolia Rafinesque)
Because it somewhat resembles the sour orange, the myrtle-leaf orange (chinotto of Italy, chinois of France) is commonly considered to be a botanical variety of C. aurantium L. Indeed,
the presumption is that the myrtle-leaf orange originated as a mutation
from the sour orange. The differences are sufficiently great
and the degree of variation exhibited so wide, however, as to appear to
justify separate species standing.
The several forms of the myrtle-leaf orange are all characterized by low vigor,
slow growth, and small trees with brachytic thornless branchlets, the
internodes of which are so short that the leaves are crowded and the
growth habit more or less dense and compact. The leaves are
very small, dark green, and usually but not always
lanceolate-pointed. The fruits are small, oblate to round,
with more or less rough rind surface and orange to deep orange in
color. The seed content is highly variable and ranges from
few or no seeds to many.
The
myrtle-leaf orange has been known for some centuries in the
Mediterranean and, as its Italian and French names imply, was presumably
introduced from China. It is grown primarily as an
ornamental though the fruits of certain forms have long been prized and
used for candying or "crystallizing" whole. Its commercial
culture appears to be confined largely to the province of Liguria,
Italy. Elsewhere it is an attractive and useful ornamental.
At least four forms or varieties of myrtle-leaf orange are recognized
and there are doubtless several clones of each. Three of
these forms have leaves which resemble those of the myrtle; the leaves
of the fourth are more like those of the boxwood. The
varieties are as follows:
Boxwood Leaf Chinotto (Chinois à Fouilles de Buis)
This form or variety is less dwarfed than any of the other chinottos
and is characterized by somewhat larger, oval-shaped and round-pointed
leaves that resemble the boxwood rather than the myrtle. The
tree is round-topped and symmetrical with dense, dark-green foliage and
is highly ornamental. The only clone grown in California is
unfruitful and it is not known whether fruitful clones exist in the
Mediterranean.
Crispifolia Chinotto (Crinkle-Leaf Chinotto)
This variety, known only in the Mediterranean basin, is reported to be
less dwarfed and more upright in growth than any of the other
myrtle-leafed forms and is said to be characterized by crinkled or
twisted leaves.
Large Chinotto (fig. 4-29)
This variety resembles the small chinotto (see below), but the plant is
less dwarfed and larger and the growth habit less
compact. The leaves are broader and somewhat larger and the
flowers less showy. The large chinotto is highly productive
and the fruits are also larger and hang well on the plant, making it
ornamental the year round. The fruit is well adapted to
preserving or candying. Seedless clones have been reported.
Small or Dwarf Chinotto (fig. 4-30)
This is the smallest of the myrtle-leaf oranges. The plant
is a highly dwarfed thornless tree or shrub with very small, clustered,
myrtle-like leaves and a compact, symmetrical, round to broadly conical
form. It blossoms profusely but varies greatly in
fruitfulness. Some clones bear very little but others are
highly productive. The fruit hangs until picked so the
appearance is that of everbearing.
Bergamot (Citrus bergamia Risso)
While the distinctive fruit of the bergamot (bergamotto of Italy, bergamote of
France) is sometimes referred to as an orange, its resemblances to the
oranges are so remote or lacking that it seems best to employ the
European usage. Both the origin of the name and its
significance are obscure. It appears to be a hybrid of the
sour orange, however, for which reason it has commonly been regarded as a
botanical variety of C. aurantium L. Since the
differences are numerous and marked and a wide degree of variation is
exhibited, separate species standing seems to be justified.
The tree is moderately vigorous, upright to spreading in habit,
virtually thornless, and with new shoot growth not pink- or
purple-tinted. At full maturity it is medium-small to medium
in size. The leaves are large and somewhat like the lemon in
color, form, and emargination, although the blades are sharper-pointed
and the petioles are longer and more broadly winged.
The flower buds and flowers are medium-large and pure white and there
is but one bloom. The lemon-yellow-colored fruits are small
to medium-large, oblate, round obovate or broadly pyriform, frequently
possess a small navel, and usually have a persistent
style. The rind is medium-thin with a smooth to moderately
rough surface, commonly ridged, and adherent. The segments
are numerous and the core solid. The flesh is moderately
firm, pale greenish-yellow, and highly acid with a faint bitter
aftertaste. The highly monoembryonic seeds, comparatively few
and sometimes none, often are not well developed. The
cotyledons are white or faintly green.
A distinctive characteristic of both foliage and fruits is the strongly
pungent and agreeably aromatic oil, which is similar to that of the
sour orange leaf, though the rind oil of the latter is different.
The bergamot has been known in the Mediterranean for several centuries,
the distinctive and desirable characteristics of its oil having been
recognized as early as 1750. Two kinds were described by
Volckamer (1708-14, p. 155) and five by Risso and Poiteau
(1818-22). Presumably it originated as a seedling in southern
Italy. While there is general agreement that the sour orange
has one parent, the other parent is a matter of
conjecture. It has usually been assumed that it was the
lemon, but Chapot (1962b) has presented rather convincing
evidence in support of the conclusion that some kind of acid lime was
the other parent. In this connection, it may be of interest
to note that the distinctive aroma of bergamot oil occurs also in the
limettas (C. limetta Risso) of the Mediterranean basin, which are sometimes incorrectly referred to as bergamots.
For reasons that are not clear, the commercial culture of this fruit,
which is grown primarily for the rind oil, is virtually confined to the
province of Calabria in southern Italy, where the most recent statistics
indicate a total planting of approximately 7,500
acres. While the tree grows and bears well in Sicily and in
portions of North Africa and elsewhere, reportedly the oil is highly
variable, inferior in quality, and therefore unprofitable.
Bergamot oil is commercially important because it constitutes the base
of cologne water (eau de cologne), perhaps the most widely used toilet
water, and also has other perfumery uses. According to Chapot
(1962b), this cologne water was developed in Cologne in 1676 by
an Italian emigrant, Paolo Feminis, and commercialized by his
son-in-law, Gian Maria Farina. Its manufacture dates back to
1709. Bergamot petit grain oil is another product, of minor
importance, distilled from the leaves and young growth. An
important byproduct of the highly acid juice in the oil extraction
process is citrate of lime or citric acid.
Varieties. —Several forms or varieties of bergamot are recognized, among which are the common Bergamot, Melarosa, Torulosa, and Piccola.
The common bergamot (bergamotto of
Italy) appears to consist of two clones which are often confused with
each other and, in fact, frequently overlap in characteristics: Femminello (note also the lemon variety of the same name) and Castagnaro. The two clones are listed separately with other varieties below and their principal differences are as noted by Chapot (1962b).
Castagnaro (fig. 4-31)
The tree is more vigorous and upright and attains larger size than the
Femminello but is somewhat less fruitful. The fruit is
prevailingly round and sometimes slightly ribbed, but frequently
exhibits a short neck and obovate form. The rind surface is
commonly rougher and the oil is usually somewhat less aromatic than
Femminello.
Femminello
The tree is somewhat less vigorous and smaller than Castagnaro but
earlier and more regular in bearing. The fruit is spherical or nearly so, the rind smooth, and the oil somewhat more aromatic and hence preferred.
Femminello is considered to be the best bergamot variety and Chapot (1962b) concludes that it represents a superior selection of Castagnaro.
Femminello and Castagnaro are the two markedly preferred varieties of
bergamot and constitute virtually all of the commercial production.
Melarosa
The Melarosa variety is distinguished by the form
of the fruit, which is flat to decidedly oblate and sometimes has a
small, apical mammilla. It is of minor and local importance
only.
Petite
See under Piccola below.
Piccola (Petite)
This form was described by Risso and Poiteau (1818-22) and while
mentioned in subsequent literature is unknown to the writer or to Chapot
(1962b). If Piccola were a true bergamot, it seems to have disappeared. More probable, however, is the likelihood
that it represents a variant seedling clone or that the name was
erroneously used for one of the dwarf perfumery varieties of the sour
orange, such as Bouquet.
Torulosa (Striata)
This variety is also characterized by the fruit, which is somewhat
larger than Melarosa and broadly pyriform or obovoid. Its
most distinctive feature, however, consists in the numerous, small,
longitudinal and darker-colored ridges in the rind which give it a
striated or striped appearance. The peel also averages
thinner than in the other bergamots.
Torulosa has no commercial importance.
THE MANDARlNS
Principal in importance in the Orient are the mandarins, a large,
distinctive, and highly varied group that includes some of the finest
and most highly reputed citrus fruits. Closer in resemblance
to the oranges than to any of the other groups, these fruits are
commonly referred to as mandarin or loose-skin oranges—a usage
which is both unfortunate and confusing in view of the numerous, highly
distinctive differences between the two groups. In the United
States, where the name tangerine first came into common usage,
mandarin and tangerine are used more or less interchangeably to
designate the whole group. Since mandarin is the older and
much more widely employed name, its use is clearly
preferable. Presumably because of the orange-red color of the
Dancy variety, which originated in Florida and was introduced in
the markets as the Dancy tangerine, horticulturists have tended to
restrict the use of the term tangerine to the mandarins of similar deep
color. However, this is a usage of convenience only and the
tangerines do not comprise a group of natural
significance. The mandarin is the mikan of Japan, the suntara or sangtra (numerous modifications) of India, the mandarino of Italy and Spain, and the mandarine of French-speaking countries.
While the range of variation in characters exhibited by the mandarin
group is much greater than in the oranges or pummelos and grapefruits
and the existence of a number of species is indicated, the distinctive
features of the group as a whole are as follows:
Fruit very small to medium (prevailingly smaller than the oranges),
oblate to highly compressed form; rind and fruit sections loosely
adherent (more so than any of the oranges); open core (much more so than
any of the oranges); flavor and aroma commonly distinctive; seeds with
greenish cotyledons (minor exceptions).
Tree very cold-resistant (more so than any of the oranges) but fruit
not; distinctive leaf petioles (wings line-margined with few
exceptions); blade notch-pointed and with main vein prominent above as
well as below; spines small and few or lacking; flowers single or in
unbranched inflorescences and prevailingly small (minor exceptions).
That the mandarin probably originated in northeastern India is strongly
suggested by the existence in the forests of Assam of a primitive form, Citrus indica Tan.,
the so-called Indian wild mandarin, together with numerous mandarin
hybrids and other and more highly developed forms not found
elsewhere. It seems clear, however, that the King and Kunenbo
mandarins must have originated in Indo-China and it is virtually
certain that the satsuma mandarin had its origin in
Japan. South China must also be the region of origin of some
of the numerous mandarins. Finally, there is considerable
reason for concluding that the Mediterranean mandarin, as the name
indicates, originated under cultivation in Europe, presumably in Italy.
According to Webber (1943), the first mention of the mandarin in Europe
relates to the introduction into England by Sir Abraham Hume in 1805 of
two mandarins from Canton, China, one of which was described and
illustrated in 1817 in the Botanical Register and the other in 1824 in Andrews Botanical Repository. Ziegler and Wolfe (1961) have concluded that one of these introductions was the highly reputed ponkan. That
the mandarin had reached the Mediterranean basin somewhat earlier seems
likely, however, for Risso and Poiteau (1818-22) mention a "mandarin
orange" which had been known there "for some years" and Chapot (1962c)
assigns the date of origin of the Mediterranean mandarin as between
1810 and 1815. From the fact that in 1830 the village of
Monroe on the St. Johns River in Florida changed its name to Mandarin,
Ziegler and Wolfe (1961) concluded that this fruit must have been
introduced into the United States about 1825. The fates of
that introduction and of another known to have been made in 1838 are
obscure. The first known successful introduction is said to
have been made by the Italian consul at New Orleans between 1840 and
1850 and consisted of the Mediterranean mandarin, which came to be known
as Willowleaf in this country (sometimes erroneously called China).
In general, mandarin trees are the most cold-resistant of the citrus
fruits of commercial importance, although some of the hybrids, notably
the Temple variety of Florida, are striking exceptions. So
far as is presently known, the satsuma mandarins are the hardiest and
the King and kunenbo group the tenderest. Primarily because
of the small size and thin rind of the fruit, however, the mandarins are
more subject to cold damage than the oranges or
grapefruit. Likewise, the mandarins are among the most
heat-resistant of citrus fruits, comparing favorably with the
grapefruit, although exposed fruits may become sunburned. The
mandarins, therefore, have a wider range of climatic adaptation than
any other citrus group. They also exhibit a wider range in
total heat requirement and hence season of maturity. Thus,
under comparable conditions, the earliest satsuma mandarins attain
horticultural maturity earlier in the fall than any of the oranges or
grapefruits, and the King mandarin and some others ripen the following
spring or early summer fully as late or later than the latest oranges or
grapefruit. It should be noted, however, that the
development of good flavor seems to require a period of relatively hot
weather during the latter part of the growing season. Some of
the mandarins, notably the Dancy variety, appear to have a lower
chilling requirement for good color development than do the oranges in
general, since they color better in semitropical and tropical
climates. Under similar conditions, however, satsuma
mandarins are especially slow in color development and commonly attain
horticultural maturity while still poorly colored. For
reasons that remain obscure, this fruit is climatically better adapted
than the oranges to the monsoon regions of the Orient, where mandarin
culture is highly important.
Environmental influences on mandarin fruit characteristics are
especially pronounced and important. Fruit size is markedly
enhanced by beat and high atmospheric humidity. Fruit form is
materially and unfavorably affected by low atmospheric humidity, which
causes the axis to lengthen and the shape to become rounder and less
oblate. In addition, the tendency to development of a neck,
present in most mandarins, is accentuated. As a consequence,
the form may change from oblate to pyriform. Such effects are
most pronounced on some of the tangelos and the differences between
desert-grown and coastal fruits of the same variety in California may be
so marked as to be scarcely credible. Both composition and
flavor also are markedly influenced by climatic factors. In
hot, humid climates the fruit is juicier and milder in flavor because of
lower acid content. Moreover, the effects of rootstocks on
these and other characteristics of the fruit may be even more pronounced
and highly unfavorable. Thus, the rough lemon rootstock so
markedly affects the composition of certain mandarins that they are
insipid in flavor. In addition, it materially shortens the
period they can be held on the trees without loss of quality from
granulation. These effects seem to be accentuated on
light-textured soils, and vice versa. In this connection it
should be remarked, however, that certain rootstocks, notably trifoliate
orange and sour orange, enhance the quality of most mandarins and
extend the period of its retention in the fruit while still on the
tree. Among varieties most sensitive to such influences is
Temple in Florida.
The above-mentioned
climatic tolerances, requirements, and influences serve to explain why
commercial mandarin culture in the United States has developed primarily
in Florida and elsewhere is restricted to the hottest portions of
California and Arizona, where it still may be regarded as somewhat
experimental,
The production problems
and practices most distinctive to commercial culture of the mandarins
and their hybrids—in particular the tangelos—appear to be concerned with
bearing behavior and fruit size. Some of the
mandarins—notably the Mediterranean mandarin and its hybrids, and Dancy
also to some degree—exhibit a pronounced tendency to alternate bearing
in which the large crops consist of undesirably small, unmarketable
fruits. Not uncommonly, excessively large crops result in
little or no bloom the following season. Thus far, attempts
to regulate bearing behavior and control fruit size to some degree have
been comparatively unsuccessful, although fruit-thinning accomplished by spring
pruning in the heavy crop years has been reported to be helpful and is
sometimes practiced. Chemical fruit-thinning sprays have
shown promise, particularly on mandarins; they are thus far limited in
effectiveness because of difficulty in predicting the degree of
thinning.
While most citrus fruits
are strongly parthenocarpic and require neither pollination nor seed
formation for fruitfulness, this is not the case with certain
mandarins—particularly the standard Clementine and the Orlando and
Minneola tangelos. The presence of seed is requisite to
fruitfulness for those mandarins and can be assured only by
cross-pollination, since they are partially
self-incompatible. While limb girdling has been reported
helpful for the Clementine in Morocco, it would appear safest to
interplant with suitable pollinators.
Among the fruit-handling problems encountered in mandarin culture are
the comparative shortness of the fresh-fruit season and the sensitivity
of fruit to injury during handling operations. With only a
few exceptions, the "on-tree" life of ripe mandarin fruits with
retention of satisfactory quality is restricted to a few weeks, after
which the rind "puffs" and both juice and acidity diminish
rapidly. If fruit is picked at the right stage and kept in
cold storage, however, the marketing season may be extended by several
months. The availability of storage facilities, therefore,
has special importance in the handling of most mandarins and
particularly such early ripening kinds as the
satsumas. Because of their thin, comparatively soft, loose
rinds the mandarins are the most delicate of citrus fruits and even with
the greatest care in all fruit-handling operations waste losses are
still often considerable.
As a
result, mandarins are comparatively high in production and marketing
costs, which are passed on in high prices to the
consumer. Consequently, in the United States and Europe the
mandarin remains a luxury or specialty fruit used largely for decorative
purposes or in gift packages for holiday season activities.
Accurate statistics on world mandarin production are not available, but
it is highly probable that this fruit was second to the sweet orange in
importance in 1965-66 with a production of between 67 and 72 million
(70-lb equivalent) boxes, which included 7 million boxes of Temple and
tangelos produced in Florida. Mandarin production is most
important in the Orient. Japan is by far the
leader—approximately 36 million boxes in 1965. Production is
high in India and China, but meaningful statistics are not
available. Florida ranks second to Japan with a 1965-66
production of about 5.4 million boxes (70-lb equivalent) of so-called
Temple oranges, 4.9 million boxes of tangerines, and 1.5 million boxes
of tangelos—a total of nearly 12 million. Spain, Italy, and
Algeria normally produce between 3 and 4 million boxes each, Morocco
about 2.5 million, and Argentina, Greece, and Egypt between 1 and 2
million each. Australia, South Africa, Israel, and Lebanon
produce a few hundred thousand boxes each. The 1965-66
production in California was a proximately 800,000 boxes (75-1b) and
will increase appreciably in the near future.
Mandarin processing is of minor importance except in Japan and
Florida. In 1964-65, about 15 per cent of the satsuma
mandarin crop in Japan was processed, the principal products being
canned fruit segments and juice. A significant portion of the
Florida production of Dancy tangerines is converted into canned
juice. Elsewhere the principal if not the only market outlet
is shipment as fresh fruit.
In
comparison with the oranges, the natural group they most resemble, the
mandarins exhibit a wider range of variation in such respects as size,
fruit color, rind adherence, flavor, and season of
maturity. While most varieties of commercial importance (the
satsumas, Dancy, Nagpur, Mediterranean, and Clementine) are medium-small
to medium in size and a few are medium-large to large (King and
Ortanique), there are a number of very small-fruited mandarins
(Cleopatra and kinokuni) of horticultural value or interest as rootstocks or ornamentals.
The color range exhibited is very great—from the pale yellowish-orange
of the Mediterranean mandarin and some other varieties to the deep
orange-red of some of the so-called tangerines such as
Dancy. In this connection, it should be noted that pigmented
mandarins, comparable to the blood oranges, apparently do not
exist. The so-called blood mandarin (mandarine sanguine) of Morocco is merely a deep orange-red-colored variety, the flesh of which is completely lacking in pink or red coloration.
With respect to degree of rind adherence, some of the mandarins (Ellendale, Clementine, and the naartje of
South Africa) have rinds that are rather closely adherent—though
readily peelable—and remain so even after horticultural maturity in
contrast with other varieties (the satsumas, Dancy, and Mediterranean)
in which the rind is loosely adherent at maturity and continues to
separate thereafter. The range of variation in flavor and
aroma is also great—from bland to rich and fragrant. So far
as the writer has been able to ascertain, however, there are no acidless
mandarins comparable to the sugar or acidless oranges. On
the other hand, Swingle (1943) reports there are several small-fruited
mandarins (sunkat of South China and others) that are highly acid
at maturity and never become edible. Finally, the length of
season during which mandarin varieties attain maturity is somewhat
longer, since some of the satsumas ripen earlier than any of the sweet
oranges and the King mandarin is fully as late or later than the
Valencia orange.
With respect to seed
content, the two groups are similar in that there are seedy, slightly
seedy, and seedless varieties in both. However, there are
many more orange varieties of low seed content, since most mandarin
varieties are comparatively seedy. An interesting parallel
may be noted in the fact that the satsuma mandarins and navel oranges
are both seedless and for the same reasons viable pollen is not produced
and functional ovules are exceedingly few. While navel
varieties of the mandarin are not known, the satsuma group exhibits a
marked tendency to develop small navel-like
structures. Certain other mandarins possess this tendency,
but less markedly.
Natural Groups
Although obviously closely related, the mandarins are clearly separable
into several natural groups. Their classification into three
species by the American authority Swingle (1943) seems untenable,
especially in view of the fact that the Japanese systematist Tanaka
(1954) has recognized 36 species of mandarins. Tanaka's
classification, which clearly is the most comprehensive treatment
undertaken thus far, places the mandarins in the following five
taxonomic groups:
I. Section Acrumen—Subsection Euacrumen.
Characterized by large flowers, leaves, and fruits.
Three species: nobilis, unshiu, and yatsushiro.
II. Section Acrumen—Subsection Microacrumen—Group Anisodora.
A distinctive small-fruited, yellow-colored group from the Okinawa and Luchu islands.
Three species: keraji, oto, and tarogayo.
III. Section Acrumen—Subsection Microacrumen—Group Citriodora—Subgroup Megacarpa.
Characterized by small flowers and leaves and medium to medium-large fruits.
Fourteen species: reticulata, deliciosa, tangerina, clementina, suhuiensis, subcompressa, paratangerina, crenatifolia, benikoji, suavissima, tardiferax,
genshokan, platymamma, and succosa.
IV. Section Acrumen—Subsection Microacrumen—Group Citriodora—Subgroup Microcarpa—Subsection Augustifolia.
Characterized by small flowers, small but narrow leaves, and small fruits.
Ten species: tachibana, kinokuni, sunki, reshni, indica, erythrosa, ponki, oleocarpa, pseudo-sunki, and tardiva.
V. Section Acrumen—Subsection Microacrumen—Group Citriodora—Subgroup Microcarpa—Microgroup Latifolia.
Characterized by small flowers, small but broad leaves, and small fruits.
Six species: depressa, amblycarpa, leiocarpa, tumida, lycoperaeformis, and hainanensis.
Of these thirty-six species Swingle recognized only tachibana and indica, wild species of Japan and India, respectively, and reticulata in
which he placed all others. While the validity of some of
Tanaka's species may be questioned, in the opinion of the writer some of
them are soundly based. Although
the writer has seen two-thirds of the species in question, his
competence is limited to only a quarter of them and, unfortunately, to
only four of the fourteen of Group III, which is characterized by small
flowers and leaves but medium to medium-large fruits and hence has
contributed numerous varieties of economic importance. As a
consequence, but with hesitation and reluctance, the writer has
tentatively grouped all but one of them (deliciosa) with reticulata.
In the presentation which follows, the varieties of principal
importance or promise are grouped, therefore, into four species: unshiu, nobilis, deliciosa, and reticulata.
Satsuma Mandarin (Citrus unshiu Marcovitch)
This mandarin is the famous and highly important Unshû mikan (Unshiu) of
Japan. The name satsuma, by which it has become known in the
Occident, is credited to the wife of a United States minister to Japan,
General Van Valkenberg, who sent trees of it home in
1878. Satsuma is the name of a former province, now Kagoshima
Prefecture, on the southern tip of Kyushu Island, where it is believed
to have originated. This mandarin may be described as
follows:
Fruit medium-small to medium,
oblate to subglobose; sometimes slightly necked;
seedless. Orange-colored but commonly matures prior to
development of good color. Areole faint or indistinct and
small; navel frequently present. Rind thin, somewhat
leathery; surface moderately smooth and with large and prominent oil
glands; easily separable. As the fruit passes through
maturity, rind surface becomes increasingly bumpy and likewise its
separation increases somewhat. Segments 10 to 12, with tough
carpellary membranes, loosely separable; axis hollow. Flesh
orange-colored; tender and melting; flavor rich but
subacid. Pulp-vesicles short and broad. Season of
maturity very early to medium early (includes the earliest-known
mandarin varieties). Fruit holds poorly on trees after
maturity and must be picked promptly, but stores well. The
occasional seeds found have light green cotyledons.
Tree slow-growing, small to medium-small, usually spreading and
drooping, nearly thornless; foliage open. Leaves dark green,
large, long, lanceolate, and tapering at base and apex, the latter
usually taper-pointed. Both main and primary lateral veins
prominent above as well as below. Petiole slender, very long,
and wing-margined. Tree very hardy to cold and resistant to
unfavorable conditions.
The highly
distinctive satsuma mandarin is considered to have originated in Japan
sometime prior to 1600 A.D., the approximate period of the earliest
known reference to it. Since it has never been found in China
and its Japanese name Unshû is considered to be a corruption of
Wenchow, an ancient province of China, it seems likely that it
originated as a chance seedling from a fruit or form imported from that
country, probably from Wenchow Province. According to Ziegler
and Wolfe (1961), the first recorded introduction into the United
States (Florida) was by George R. Hall in 1876. The satsuma
reached California not long thereafter and within a few decades was
established in collections in the Mediterranean basin and elsewhere.
The satsuma mandarin tree is the most cold-tolerant of citrus fruits of
commercial importance, mature dormant trees having survived minimum
temperatures of 15º F to 18º F in northern California and southern
Alabama without serious injury. Moreover, because of its
apparent low total heat requirement, some varieties ripen earlier than
any of the oranges or other mandarins. However, warm weather
is required during the growing season for the development of
satisfactory quality. As a consequence, the satsuma is
adapted to regions of winters too cold for other citrus fruits and with
growing seasons sufficiently warm to produce fruit of early maturity and
good quality. For reasons that remain obscure, this mandarin
has not proven commercially successful in the milder and hotter
portions of the subtropics or in the tropics. Its range of
climatic adaptation for commercial culture is therefore narrow and restricted to the upper and colder portions of the subtropical zones.
In the United States, climatic conditions suitable for satsuma mandarin
culture occur in parts of northwestern Florida, in a narrow strip
extending along the Gulf of Mexico across Alabama, Mississippi, and
Louisiana into eastern Texas, and in the thermal belt of the
Sacramento-San Joaquin Valley basin of California. Some
decades ago, there existed in the Gulf Coast region what appeared to be a
thriving and promising young industry of some thousands of
acres. Primarily because of a series of unprecedented
vicissitudes—introduction of the citrus canker disease and necessity for
its eradication and recurrent devastating freezes—those plantings have
virtually disappeared. Replacements currently comprise only a
fraction of the original acreage. At about the same time,
small plantings were made in the Sacramento Valley of California which
persisted for several decades but ultimately were removed or largely
replaced with other varieties, primarily because of handling and
marketing difficulties and possibly rootstock-scion incompatibility
problems involving virus diseases. In recent years, however,
there has been a revival of interest in this mandarin and about 1,500
acres have been planted, principally in the San Joaquin Valley.
In portions of southern Japan, climatic conditions are favorable to the
production of early ripening satsuma mandarins of high quality and
maximum size, which has permitted the development of the world's largest
and most important mandarin industry. The total planting in
Japan for 1963 was reported to be 215,000 acres with a production of
about 28 million 70-lb box equivalents. The areas of
production are widely distributed, involving the islands of Honshu,
Shikoku, and Kyushu and nineteen prefectures (chap. 2, table 2-69, p.
142 [text version, Revised Ed.]). At the present time,
satsuma mandarins comprise about 80 per cent of the citrus acreage and
account for approximately a third of the total fruit tonnage harvested
in Japan.
While this fruit is grown
primarily for fresh consumption, a significant and increasing portion of
the crop is canned as fruit segments or juice. Limited
quantities of fresh fruit have been exported to Canada, where they have
comprised the earliest new-crop citrus fruits to reach the
markets. Export of canned fruit segments has increased
greatly in recent years and this excellent product is now found in both
American and European markets.
The
most unusual or distinctive features of the Japanese industry are as
follows: (1) much the greater part of the orchards are close-planted and
are situated on relatively steep, bench-terraced slopes; (2) the
rootstocks used are trifoliate orange (Poncirus trifoliata [L.] Raf.) and Yuzu (C. junos Siebold),
mainly the former; (3) a common and recommended practice is inarching
trees on trifoliate rootstock at 12 to 15 years of age or even older
with Yuzu seedlings to offset dwarfing and prolong their
productive life; (4) the employment of regular and severe pruning; and
(5) the availability of extensive storage facilities which make possible
notable extension of the fresh-fruit marketing and processing seasons.
At the dawn of modern horticulture in Japan, five kinds, groups, or varieties of unshu mikans
were recognized, three of the names of which refer to localities or
districts, one to season of maturity of the fruit, and the other to
antiquity of origin. These horticultural groups are as
follows:
1. Wase (Early)—All
early-ripening clones were placed in this group irrespective of origin,
known or otherwise. Indeed, all varieties of Unshû are
classified into two groups—Wase Unshû (earliest to ripen, hence very early) and Unshû
(ripening later, but still early). More recently the latter
has been subdivided into the intermediate or midseason varieties—Nakate Unshû—and the late ripening varieties—Futsu Unshû. Wase itself
is therefore not a horticultural variety but constitutes a group of
very early ripening varieties, each of which carries its own
name. In general, however, these varieties are distinctively
different from the typical Unshû.
2. Zairai (Native,
indigenous, or old)—This group is said to include what are considered
to be the oldest clones of unknown parentage or origin. Thus,
Miyagawa, currently the most important of the Wase varieties, is known to have originated as a limb sport in a Zairai tree. Zairai does not exist as a named variety, however, though Zairai
clones as a group are usually seedy and inferior in other
respects. They are reported to have originated mainly in
Fukuoka Prefecture of Kyushu Island where the Unshû was early taken from Satsuma Province.
3. Owari (an
old province on Honshu Island, now Aichi Prefecture)—This group, much
the most important, represents an old clonal variety which early became
popular and predominant in Owari Province and may have originated there,
although it is thought to have come from Ikiriki of Nagasaki
Prefecture. Because of its excellence, it spread throughout
the country and until approximately 1940 was virtually the only variety
planted commercially. Since World War II, however, the
plantings have been restricted largely to derivative varieties known to
have originated as bud mutations in Owari trees. Owari itself
seems no longer to be propagated as a clonal variety, though it still
comprises the bulk of the production. As a group it is
characterized by good tree vigor and productivity and flat fruit of good
quality which, because of the firm consistency of the flesh and tough
carpellary membranes, is especially suitable for canning.
4 and 5. Ikeda and Ikiriki
(town or village names in Osaka and Nagasaki Prefectures)—These groups
seem also to represent old varieties of local origin no longer
propagated, though old plantings still exist—of the former, on Shikoku
Island and in nearby Wakayama Prefecture on Honshu Island; of the
latter, mainly in Saga and Nagasaki Prefectures of Honshu Island.
Ikeda is reported to be characterized by small, subglobose, and
virtually seedless fruit of mediocre quality and relatively late
maturity. The trees of Ikiriki are said to be small, compact,
and not very productive, but the fruit is reported to be seedless and
of excellent quality.
During the
period of 1908-1911, approximately a million satsuma trees were imported
and planted in the United States. A few years later, a study
of the varieties included in the importations (Scott, 1918; Tanaka,
1918) disclosed that they consisted mainly of the Owari type or variety,
although three others—Wase, Ikeda, and Zairai—were also identified and
described. In view of these facts, the authenticity of the
Wase and Zairai clones in question is doubtful at least and the clones
of Owari and Ikeda should probably be regarded as selections of those
varieties. Fortunately, however, the Owari identified and
propagated in the United States appears to be true to type for
Silverhill, a seedling clone derived from it in Florida and
considered to be of nucellar origin. It has been tested in
Japan and is among the clones currently recommended for planting there.
The satsuma mandarins must be regarded as a highly unstable group, for
as early as 1932 Tanaka (1932) reported numerous bud variations of which
some thirty were named and described. This list has now been
extended to a hundred or more, some of which appear to be identical
although of different origin. Of current importance or
promise are the varieties described below, nearly all of which are
derivatives of Owari.
Early (Wase) Varieties.—Since
the satsumas are characterized by early fruit maturity, the Wase
varieties are very early ripening—late September and
October. As a group the trees are said to be more or less
lacking in vigor, slow growing, and dwarfed. They have
moderately dense foliage consisting of relatively small leaves with
slender, fairly line-marginated petioles. The Wase varieties
comprise about one-fifth of the total mandarin acreage in
Japan. The descriptions that follow are from M. Nishiura of
the Horticultural Research Station at Okitsu, Japan.14
Aoe (Aoe Wase)
Aoe is primarily of historical interest. It is said to be
the oldest known and hence, perhaps, the original variety of this early
ripening group. While no longer propagated, it is still
important in some of the older districts of Japan.
Iseki (Iseki Wase)
Iseki is currently confined to Koneshima Island in the sea of Japan,
where it is gradually being replaced by the larger-fruited Miyagawa
variety. It is considered to have outstanding eating quality.
Matsuyama (Matsuyama Wase)
Fruit somewhat more oblate than Miyagawa, the leading Wase variety, but
reported to mature slightly earlier.
Tree also more vigorous. Tested rather widely and considered to be highly promising.
Matsuyama originated as a limb sport in an Owari tree on the property
of U. Ukumori, at Matsuyama, Ehime Prefecture. The variety
was found about 1935 and registered in 1953.
Miho (Miho Wase)
Fruit somewhat more oblate than Miyagawa, but higher in sugar, usually
lower in acid; and earlier in maturity.
Tree also more vigorous. Markedly similar to Okitsu, but
fruit from young trees has been slower to color and in some location
trees have been somewhat more vigorous.
The Miho variety originated as a sister nucellar seedling to Okitsu but
seems to have the slight differences mentioned above. It was
registered in 1963.
Miyagawa (Miyagawa Wase) (fig. 4-32)
Fruit large (for satsuma), moderately oblate, with thin and smooth
rind. Seedless. Juice abundant, sugars and acid
well-blended, and quality excellent. Matures very early and
stores well for Wase Unshû.
Tree more vigorous than most old Wase clones and productive.
Miyagawa originated as a limb sport in a Zairai tree in Fukuoka
Prefecture and was named and introduced by Dr. Tyôzaburô Tanaka in
1923. It is currently the best known and much the most
extensively grown of the Wase varieties.
Okitsu (Okitsu Wase) (fig. 4-33)
Fruit somewhat more oblate than Miyagawa, but averages higher in sugar
content and matures a week or so earlier. Trees also more
vigorous.
Okitsu originated as a nucellar seedling of Miyagawa from a controlled pollination with Poncirus trifoliata made
by Doctors M. Kajiura and T. Iwasaki at the Horticultural Research
Station, Okitsu, in 1940. It was distributed for trial in
1953, registered in 1963, and appears to be highly promising.
Late (Unshu) Varieties.—The late satsuma varieties ripen in November-December and hence are early to medium-early in their maturity season.
Hayashi (Hayashi Unshû)
Fruit medium-large; sugars and acid relatively high; keeping quality
exceptionally good; otherwise like Sugiyama, the principal variety. Medium-early in maturity (December).
Tree very vigorous (for satsuma), productive, and more upright than Sugiyama.
Hayashi originated as a bud variation of Owari on the property of B.
Hayashi in Wakayama Prefecture and was found about 1920 and introduced
in 1925. It is grown primarily as a shipping variety and
stores well.
Ishikawa (Ishikawa Unshû) (fig. 4-34)
Fruit very large (one of the largest); rind finely pitted; sugar and
acid both high; keeping quality very good. Maturity season
late for satsumas (mid-December). Otherwise like most other varieties.
Tree vigorous (for satsuma), with large, long, somewhat-drooping
branches; leaves larger than most other varieties.
The Ishikawa variety originated as a bud mutation of Owari in the
orchard of K. Ishikawa in Shizuoka Prefecture. It was noted
about 1934 and registered in 1950. This variety is grown
primarily because the fruit is late to mature and stores well.
Nankan No. 4
Fruit large; sugars high and acid low; early in maturity
(November). Otherwise not distinctive. Tree vigorous and
productive.
Nankan No. 4 originated as
a bud variation of Owari on the property of S. Yakushiji in Ehime
Prefecture and was introduced about 1925. It is an early
shipping variety in some prefectures.
Owari (Owari Satsuma)
Fruit medium in size, medium-oblate to subglobose; sometimes slightly
necked; seedless. Orange-colored but commonly matures in
advance of good coloration. Rind thin and leathery; surface
smooth to slightly rough; easily separable. As maturity
passes, the neck, if present, increases in size, the rind roughens, and
its looseness increases, becoming baggy. Segments 10 to 12,
with tough carpellary membranes; loosely separable; axis
hollow. Flesh orange-colored; tender and melting; flavor rich
but subacid. Season of maturity earl
November-December. Fruit holds poorly on trees after maturity
and must be picked promptly but stores well.
Tree moderately vigorous but slow-growing,; medium-small, spreading and
drooping; very productive.
This
variety is of ancient and unknown Japanese origin presumably from the
old province of Owari, whence the name. While still important
in the older districts it has largely been displaced by derivative
varieties that have arisen from it through bud
variation. What is believed to be true Owari was introduced
into the United States more than fifty years ago and, since recent
Japanese descriptions of it are not available, the characterizations
given here are adapted from Webber (1943). Two nucellar
selections, Silverhill Owari and Frost Owari, have been derived from it
in the United States and are currently recommended. Kara, a
variety of some interest in California, is a hybrid between Owari
satsuma and King mandarin. Likewise, the Umatilla tangor of
Florida is an Owari satsuma-Ruby blood orange hybrid.
Silverhill (Silverhill Owari)
Fruit medium in size, slightly more oblate than most; rind relatively thin and smooth; seedless. Juice abundant; sugars high and acid low (hence very sweet); quality excellent; stores well. Season of maturity early (November).
Tree very vigorous (for satsuma), more upright than most others; productive; markedly cold-resistant.
Silverhill is a nucellar seedling selection of Owari from a cross made
by W. T. Swingle of the U.S. Department of Agriculture in Florida about
1908. The variety was named and introduced about
1931. In collections in California, it is
indistinguishable from the Frost Owari derived at the Citrus Research
Center, Riverside, California, and almost certainly they are
identical. They constitute what are considered to be the best
clones currently available in the United States.
Silverhill has been tested in Japan, where the above characterization
was taken to permit direct comparison with other
varieties. It is recommended for planting in Japan as a
promising, early shipping variety of Unshû.
Another nucellar selection, which so closely resembles Silverhill that
it is virtually indistinguishable, is Tanikawa Unshû, which
originated as a nucellar seedling in the breeding program of the
Horticultural Research Station at Okitsu about 1920 and was named for
its originator, T. Tanikawa. The only differences reported
are a somewhat lower average sugar content in the fruit and slightly
higher average yield to date. Like Silverhill, it is
recommended as an early shipping variety.
Sugiyama (Sugiyama Unshû) (fig. 4-35)
Fruit large (for satsuma), oblate; rind relatively thin and smooth;
seedless. Juice abundant; sugars relatively high and acid
low; quality excellent. Early in maturity (November).
Tree moderately vigorous, spreading, drooping, and productive.
Sugiyama originated as a bud variation of Owari in the orchard of J.
Sugiyama in Shizuoka Prefecture. First noted about 1930, it
was introduced in 1934. It is one of the principal shipping
varieties and is widely grown.
Minor Varieties.—Satsuma varieties grown on a limited scale and those which offer promise for the future are described below.
Dobashi-Beni Unshu
Distinctive only because of its deep orange-red color. Fruit
of good quality, ripening in late November or early December.
Tree of medium vigor.
This variety originated as a limb sport of Owari in the orchard of K.
Dobashi in Shizuoka Prefecture and was noted about 1940. In
marked contrast is Yamabuki Unshû, which is characterized by yellow rind and flesh.15
Juman Unshu
Vigorous-growing, small-leafed, late-ripening (December)
variety. Fruit medium-large; rind surface finely pitted;
flavor rich; very good keeping quality.
The Juman Unshû is considered to be promising as a late shipping and
storage variety for the warmer sections of Japan. It
originated as a bud mutation of Owari in the orchard of K. Juman in
Kochi Prefecture (Shikoku Island) and was named and registered in 1953.
Nagahashi Unshu
This variety is very similar to Yonezawa below, but the fruit is not as
bright in color and both tree vigor and fruit quality are
inferior. A limb sport of Owari that originated on the place
of T. Nagahashi in Shizuoka Prefecture, this variety was noted about
1935.
Yonezawa Unshu
Very large-fruited, bright-colored, early ripening variety that closely
follows the Wase varieties. Tree vigor somewhat lacking,
however, and fruit quality only mediocre.
This variety originated as a limb sport of Owari on the property of Y.
Yonezawa in Shizuoka Prefecture and was named and registered in 1955.
Fruits Resembling the Satsuma
Yatsushiro (Yatsushiro Mikan)
An older mandarin the fruit of which more closely resembles satsuma
than any other, according to Tanaka (1961a), is the Japanese Yatsushiro mikan (C. yatsushiro Tanaka),
currently of minor and decreasing importance because of an inability to
compete with satsuma. Although of smaller size and sometimes
moderately seedy, the fruit is well-colored, juicy and pleasantly
sweet. The leaves, however, are not satsuma-like and are
definitely winged.
Of ancient Japanese origin, Tanaka (1961a) considers this fruit to have been derived from the small-fruited Kishû mikan (C. kinokuni Tan.).
King Mandarin (Citrus nobilis Loureiro)
The most widely employed name for this little known and relatively
unimportant group derives from the American variety known as King which
came from Indo-China (South Vietnam) and closely corresponds with
Loureiro's original description of the species nobilis. In
the earlier French literature, it was commonly referred to as the
Indo-Chinese or Camboge mandarin. The Japanese name kunenbo (Kunembo)
applies to forms that occur there and in China, Taiwan (Formosa), and
Okinawa, which are somewhat different but are considered to belong to
this species.
It appears to be the
consensus that the King group originated in Indo-China, whence it spread
northward as far as Japan and southward throughout
Malaya. Many of the mandarins currently found in the Malayan
region and a few in China appear to be of the nobilis type. Some
of the characters exhibited by this group are orange-like and others
are intermediate between that fruit and mandarin, which supports the
conclusion that King probably originated as a hybrid between the two and
is therefore a natural tangor.
That there are consistent and possibly significant differences between the Kunenbo (fig. 4-36) and King (fig. 4-37) mandarins has been pointed out recently by Tanaka (1961b),
but he still considers them as belonging to the same
species. The principal differences he mentions are the larger
size and the thicker tuberculate rind of the King as compared to the
thinner and smoother rind of Kunenbo and the shorter, less-strongly-beaked seeds with cream-colored cotyledons of Kunenbo. To these the writer would add a more acrid rind oil and slightly bitter flesh taste for Kunenbo
and a considerably more upright and irregular habit of growth for the
King, with leaves that are less mandarin-like in form and
appearance. Several kinds of Kunenbo have been described by Tanaka (1961b),
and a number of clones have been reported in Indo-China and Malaya
which appear to be similar to the King variety of the United States
described below.
King (King of Siam) (fig. 4-37)
Fruit large (among the largest of the mandarins), oblate to depressed
globose; base sometimes short-necked but usually depressed and furrowed;
apex flattened or depressed; areole moderately
distinct. Rind thick (very thick for mandarins), moderately
adherent but peelable; surface moderately smooth to rough and
warty. Deep yellowish-orange to orange at
maturity. Segments 12 to 14, readily separable; axis large
and hollow. Flesh color deep orange; tender; moderately
juicy; flavor rich. Seeds few to many and cotyledons
cream-colored. Late to very late in maturity and stores well
on tree.
Tree moderately vigorous,
upright and open in growth habit, and medium in size, with comparatively
few thick, stiff and erect, thornless to moderately thorny
branches. Foliage open and consists of large, dark-green,
broadly-lanceolate leaves, the petioles of which are medium in length
and narrowly wing-margined and the venation inconspicuous in comparison
with most other mandarins. Very, productive but markedly
subject to loss from tree breakage and fruit sunburn. Tree
cold-resistant but less so than most mandarins.
According to Webber (1943), this variety originated as a seedling from
fruits of that name received by H. S. Magee of Riverside, California, in
1880 through the courtesy of the United States Minister to Japan, John
A. Bingham, who arranged to have them sent from Saigon, Cochin-China
(South Vietnam). It is stated that Magee, who was a
nurseryman, sent both seedlings and budwood to J. C. Stovin of Winter
Park, Florida, in 1882.
Climatically,
the most distinctive feature of this variety is its very high heat
requirement for the attainment of horticultural maturity and good
quality, for which reason it is the latest ripening of the
mandarins. The fruit also is markedly affected by
environmental influences, including both rootstock and
soil. Thus, when grown in Florida on sour orange rootstock in
the heavier-textured soils, the size is large, rind surface relatively
smooth, and the flavor excellent—rich and sprightly. On rough
lemon rootstock in light-textured soils, the rind surface is rough and
warty and the flavor much less pronounced. As a consequence,
for satisfactory quality its range of commercial adaptation is quite
restricted. In California, it attains acceptable flavor only
in the hottest interior districts and is undesirably rough in rind
surface and unattractive in appearance.
At one time King had considerable importance in Florida, but it is now
grown very little commercially. It is still used in the
gift-package trade, however, and for home planting. It has
never achieved importance in California.
Of horticultural interest in connection with this variety is the fact
that several of its hybrids are currently of commercial interest in
California and elsewhere, among which are Encore, Honey (not the Murcott
of Florida), Kinnow, and Wilking, all of King X Willowleaf parentage,
and Kara of Owari satsuma X King parentage (Frost, 1935).
Several observers have reported similarities between the fruits of King and Campeona,
a variety of growing importance in Argentina. These
similarities include size, form, roughness and thickness of rind, white
cotyledons, and lateness of maturity.
Mediterranean Mandarin (Citrus deliciosa Tenore)
This is the common mandarin of the Mediterranean basin which is known
by many names, most of them local place names that refer to its origin
as native or are synonyms of the word common. According to
Chapot (1962c), among the principal place names are Ba Ahmed
(Morocco), Blida, Boufarik and Bougie (Algeria), Bodrum (Turkey),
Paterno and Palermo (Italy), Nice and Provence (France), Valencia
(Spain), and Setúbal (Portugal). Synonyms for common or
native are commune (French), comun (Spanish), gallego (Portuguese), koina (Greek), yerli (Turkish), and beladi (various spellings) for Arabic. Other names include Effendi or Yousef Effendi (Egypt
and the Near East), Avana or Speciale (Italy), Thorny (Australia),
Mexirica or Do Rio (Brazil), and Chino or Amarillo
(Mexico). In the United States, it is known as the
Mediterranean or Willowleaf mandarin.
The excessively numerous names by which this mandarin is known are
misleading since they suggest the probable existence of a number of
varieties. Such is not the case, however, for Chapot (1962c)
has been unable to find differences between them in collections
assembled in Morocco. Comparisons in California between Baladi (Egypt),
Avana (Italy), Comun (Spain), and Ba Ahmed (Morocco) have shown no
differences except those to be expected between old and young (seedling)
clonal lines.
Mediterranean (Mediterranean Common, Willowleaf) (fig. 4-38)
Fruit medium in size, moderately oblate, frequently slightly lobed;
base sometimes even, but usually with low collared and strongly furrowed
neck; apex depressed and commonly slightly wrinkled; areole lacking;
small navel-like structure fairly common. Seeds numerous,
small, round, plump, and highly polyembryonic, with light green
cotyledons. Rind thin, not leathery, loosely adherent;
surface smooth and glossy with large, deep colored oil glands; color
yellowish-orange at maturity. Segments 10 to 12, very loosely
adherent; axis hollow. Flesh color light orange; tender;
juicy; flavor sweet; pleasantly aromatic
(distinctive). Moderately early to early midseason in
maturity. As fruit passes through maturity, rind separation
increases sharply and "puffing" takes place, accompanied by marked loss
of acidity. Fruit loses quality unless picked
promptly. Unfortunately, fruit does not store well (in
comparison with satsuma).
Tree slow
growing, of medium vigor and size, broad-spreading, and drooping in
growth habit; branches fine, willowy, and nearly thornless; leaves
small, narrowly lanceolate, and of distinctive
appearance. Tree hardy to cold and resistant to unfavorable
conditions, but exhibits strong tendency to alternate bearing.
In comparison with the other mandarins, the most distinctive
characteristics of the Mediterranean mandarin include: (1) the small
size and narrow-lanceolate form of the leaves and the special nature and
aroma of the oil they contain; (2) the mild and pleasantly aromatic
flavor of the juice; (3) the distinctive nature and fragrance of the
rind oil; and (4) the plump and almost spherical
seeds. Additional distinctive characteristics not confined to
this mandarin are the spreading-drooping habit of growth and the very
high degree of seed polyembryony.
Since this highly distinctive mandarin appears not to have been found in
the Orient, it seems likely that it originated in the Mediterranean
basin and almost certainly in Italy. After careful review of
the literature, Chapot (1962c) has concluded that it appeared in
Italy between 1810 and 1818. It is reported to have been
imported into Egypt from Malta about 1830 and is known to have been in
commercial production in Italy by 1840, whence it was taken to Algeria
in 1850. Within a few decades, it spread to all the countries
of the Mediterranean basin and Near East and soon attained considerable
commercial importance. It was brought to the United States
by the Italian consul at New Orleans and planted in the consulate
grounds there sometime between 1840 and 1850, apparently being the first
mandarin to reach this country. Not long thereafter, it was
taken to Florida and thence probably to California and elsewhere.
The parentage and mode of origin of this fruit are not known, but it
seems likely that it arose as a chance seedling from a mandarin variety
or form of Chinese origin. Because of certain resemblances,
Tanaka (1954, p. 16) has suggested the possibility that the szu-ui-kom, szinkom, or sun-wui-kom (Citrus suhuiensis
Tan.) of southern China might be the seed parent, although he insists
that the two species are distinct. As seen by the writer in
the collection at the Government Horticultural Research Institute,
Saharanpur, India, the latter fruit exhibits numerous and striking
similarities to the Mediterranean mandarin, including the habit of
growth, appearance, and distinctive flavor and aroma of the
fruit. The leaves, however, are much more broadly lanceolate.
Because of its high beat requirement, tolerance, and the fact that the
fruit is well-shaded, this mandarin is adapted to the hot and dry
climates that characterize the Mediterranean basin and Near
East. In general, because of the greater amount of heat, both
fruit size and quality are superior in North Africa and the season of
maturity earlier than in Italy and Spain. The Baladi or
Yussef Effendi mandarin of Egypt is notable for earliness of maturity,
and size, the latter evidently an effect of the humidity resulting from
the flooding of the Nile during summer and early fall. In the
heat-deficient coastal region of southern California, the fruit is
small, of indifferent quality, and late in maturity.
Although decreasing in importance because of the substitution of other
varieties, notably Clementine, the Mediterranean mandarin currently
ranks second to the satsumas of Japan. While accurate and
complete statistics are not available, the 1961 crop was estimated at
not less than 11 million 70-lb) box equivalents. The
principal producing countries, ranked in approximate descending order of
importance, appear to be Italy and Spain, followed by Algeria, Egypt,
Brazil, Greece, and Argentina. This mandarin is of commercial
importance, however, in virtually every citrus-producing country of the
Mediterranean basin and the Near East. Early taken to South
America and grown largely as seedling trees, it is the Mexirica do Rio or Do Rio of Brazil and comun
mandarin of Argentina and Uruguay and is reported to account for most
of the mandarin production of those countries. In the United
States, it is grown as a collection item or dooryard ornamental.
Presumably because of the fruit characteristics, processing of the
Mediterranean mandarin has not been developed. Two byproducts
are made, however, principally, in Sicily: rind oil and oil of petit
grain. The rind oil is used in the preparation of perfumes
and toilet waters and for the flavoring of confections and carbonated
beverages. Petit grain, which is distilled from the prunings
and comes mainly from the leaves, has a strong and highly distinctive
odor.
The uniquely important, still
unsolved problem with the Mediterranean mandarin is how to control its
marked alternate-bearing tendency so as to regulate production and
ensure fruit of good size. Neither pruning nor fertilization,
alone or in combination, have succeeded thus far. Because of
the highly delicate nature of the rind, all handling operations must be
performed with special care to avoid fruit injury. Despite
such care, losses from decay are commonly excessive.
According to Trabut (1902a, 1902b),
the Clementine mandarin, now replacing the Mediterranean mandarin in
parts of North Africa, is probably a natural hybrid of it and the Granito
bitter orange, a view which has never received complete acceptance and
seems highly doubtful. However, this fruit is the pollen
parent of three hybrid varieties currently of any interest in California
and elsewhere—Encore, Kinnow, and Wilking—created by Frost
(1935). The seed parent of the hybrids is King mandarin.
Two new varieties of Mediterranean mandarin have been reported in recent literature, the Tardivo di Ciaculli or Ciaculli Late of
Italy (Zanini and Crescimanno, 1955) and an unnamed seedless clone in
Spain (Gonzalez-Sicilia, 1963, p. 215). A late-maturing
variety would appear to afford little advantage, but a commercially
seedless variety of good quality might well prove to be highly valuable.
Common Mandarins (Citrus reticulate Blanco)
For reasons previously discussed, the writer has provisionally included in the common mandarins (Citrus reticulata Blanco)—one of the three species recognized by Swingle (chap. 3, this work)—thirteen
of the fourteen species in Group III of Tanaka (1954). These
species are characterized by small flowers and leaves and medium to
medium-large fruits. As might be expected, this group is
quite varied and exhibits a wide range in both tree and fruit
characters. In contrast with the three other species of
mandarins presented in this treatment, some of the varieties
characterized below are "tightskin" mandarins. Although
peelable, their rinds are much more tightly adherent than the
"looseskin" mandarins and "puff" very little—if at all. In
addition, they usually have more solid axes. Certain
varieties also are included such as the Clementine, Ellendale, and
Murcott, which have been or may be considered to be natural tangors.
Major Common Mandarin Varieties.—The major varieties of common mandarins are described below.
Algerian
See under Clementine.
Beauty (Beauty of Glen Retreat, Glen) (fig. 4-39)
Fruit medium in size, oblate; base usually with well developed but
small, more or less corrugated neck; apex somewhat
depressed. Rind thin, firm, but easily removed; surface
smooth and glossy; color orange-red at maturity. Segments 9
to 13, easily separated; axis medium and hollow. Flesh
orange-colored; tender; juicy; sprightly flavored. Moderately
seedy and cotyledons light-green. Midseason in maturity.
Tree vigorous, medium to large, upright-spreading, virtually thornless,
with dense foliage consisting of medium-sized, broadly lanceolate
leaves. Strong tendency to alternate bearing with undesirably
small and tart fruit in the "on" years.
Beauty is said to have originated about 1888 as a seedling on the
property of W. H. Parker, Glen Retreat, at Enoggera (a suburb of
Brisbane), Queensland. The parent variety is unknown but the
similarities with Dancy are such C as to lead R. J. Benton, former
government citrus specialist in New South Wales, to the conclusion that
this variety is a seedling of the Dancy type, which is highly
polyembryonic and reproduces remarkably true from seed.
Beauty is highly popular in Queensland, where climatic conditions favor
the production of large, superior quality fruit. It is
reported that overbearing in alternate years is successfully
counteracted by a combination of heavy pruning and hand thinning.
Campeona (fig. 4-40)
Fruit large (very large for mandarin), broadly oblate; base rounded and
commonly short-necked with prominent radiating furrows or ridges; apex
moderately depressed; smooth or with shallow radial furrows; commonly
with small, embedded navel. Rind medium-thick, comparatively
soft, moderately adherent but readily peelable; surface roughly pebbled
and somewhat bumpy with prominent, sunken oil glands; orange-colored at
maturity. Segments 10 to 13, moderately adherent; axis large
and semi-solid to solid. Flesh orange-colored; juicy; flavor
rich and sprightly (somewhat acid). Seedy to very seedy and
cotyledons white. Medium-late in maturity.
Tree of medium vigor and size; branches numerous, slender, and
thornless; foliage dense and composed of medium-sized, narrowly
lanceolate, sharp-pointed leaves.
Several competent observers have noted similarities between the fruits
of Campeona and King in rind thickness and surface characteristics,
color of the cotyledons, and lateness of maturity. As a
result, they have tentatively placed it in the King group (C. nobilis). It
is to be remarked, however, that tree descriptions of the King and
Campeona do not correspond. The Campeona has sometimes
erroneously been called Bergamotta, a name that should be abandoned.
In Entre Ríos Province of Argentina, where this variety has
considerable and increasing importance, it is said that Campeona is of
unknown Uruguayan origin and was introduced from Salta to the government
citrus station at Concordia. The quality, of the fruit is
reported to be outstanding on Poncirus trifoliata rootstock.
Clementine (Algerian) (fig. 4-41)
Fruit size variable, ranging from medium-small to medium; form likewise
quite variable, with range from slightly oblate through globose to
oblong and sometimes broadly pyriform from development of neck or
collar; base usually rounded but sometimes collared or necked; apex
depressed; occasionally with small navel. Rind medium in
thickness; moderately firm and adherent, but easily peelable and does
not puff until well after maturity; surface smooth and glossy, but
slightly pebbled because of prominent oil glands; color deep orange to
reddish-orange, but not as red as Dancy. Segments 8 to 12,
slightly adherent; axis medium and open. Flesh color deep
orange; tender and melting; juicy; flavor sweet; subacid and
aromatic. Seeds very few to medium in number (depending on
cross-pollination), monoembryonic, and cotyledons mostly green (some white). Early in maturity. While the rind puffs somewhat after maturity, on some rootstocks fruit holds on tree for several months with little loss in quality.
Tree medium in vigor and size, spreading and round-topped; branchlets
fine-stemmed, willowy, and nearly thornless; foliage
dense. Leaves highly variable in size, narrowly lanceolate in
form, and somewhat resembling the Mediterranean or Willowleaf
mandarin. In most locations, regular and satisfactory bearing
is assured only by the provision of cross-pollination. Tree
strongly cold-resistant.
According to Trabut (1902a, 1902b,
1926) this highly important North African variety originated as an
accidental hybrid in a planting of mandarin seedlings, presumably of the
common or Mediterranean mandarin, made by Father Clement Rodier in the
garden of the orphanage of the Péres du Saint-Esprit at Misserghin, a
small village near Oran, Algeria. It was one of several
aberrant plants Trabut noted and was selected by him and named
Clementine by the Horticultural Society of Algiers on his recommendation
(Chapot, 1963a). It was Trabut's conclusion that the
seed parent was the Mediterranean mandarin and the pollen parent a
willow-leafed ornamental variety of C. aurantium known as Granito. Both
Webber (1943, p. 558) and Tanaka (1954) have expressed doubt concerning
the validity of this conclusion. More recently, Chapot (1963a),
the distinguished French authority in North Africa, has refuted it with
convincing evidence. It is his conclusion that Clementine is
of Oriental origin, probably Chinese, and that it is indistinguishable
from and probably identical to the Canton mandarin described by Trabut
(1926), who also remarked on the similarities between the
two. If this Canton mandarin was authentic, these
resemblances have apparently escaped the notice of Tanaka (1954), for he
has given the species designation clementina to this mandarin.
The Clementine variety was introduced into the United States in 1909
and brought to California from Florida in 1914 by H. S. Fawcett of the
Citrus Research Center, Riverside. Evidently another
independent introduction was made, since the 1914-15 catalogue of the
Fancher Creek Nurseries of Fresno, California, mentions a new early
mandarin from Algeria which later proved to be indistinguishable from
Clementine.
At least two clones of
Clementine are known to exist in North Africa—the common ordinary and
the Montreal. While the two are indistinguishable with
respect to the tree, and virtually so for the fruit, the former exhibits
self-incompatibility, and hence the fruit is seedless or nearly so in
the absence of cross-pollination. Evidently associated
therewith is less regularity and certainty of production under
unfavorable conditions of climate or orchard management. The
Monreal clone, which was found in 1940 in the orchard of Vincent Monreal
at Perregaux, Oran, is self-compatible and without cross-pollination
the fruit is regularly seedy. The bloom is much less abundant
and the seeds slightly smaller. In this connection, it
should be mentioned that seedy fruits average somewhat larger than
seedless fruits and are also slightly sweeter. In Morocco,
selections from mother trees of outstanding bearing behavior and low
seed content have not shown significant differences. In both
Morocco and Spain, seedless Monreal clones have been reported, but thus far they have not demonstrated superiority over the ordinary clone. The Spanish clone, Clementino de Nules, is said to have originated as a budsport in Nules, Castellón Province.
Chapot (1963b)
has recently described a small-fruited mandarin which Trabut (1926, p.
4) either found or introduced and called the mandarinette. It
exhibits so many resemblances to Clementine, including seed
monoembryony and early maturity, as to suggest very close
relationship. The principal differences reported relate to
the odor of the leaf oil, the form of the seeds, and the color of the
chalazal spot.
Climatically, the
distinctive features of the Clementine variety are its low total heat
requirement for fruit maturity and the sensitivity of the seedless fruit
to unfavorable conditions during the flowering and fruit-setting
period. In regions of high total beat, the Clementine matures
very early—only slightly later than the satsuma
mandarins. Such regions also favor production of fruit of
maximum size and best eating quality. As a consequence,
Clementine is without doubt the best early variety in the Mediterranean
basin, particularly in North Africa, and is highly promising in other
regions of similar climate.
With
reference to sensitivity of seedless fruits, however, the almost
universal experience has been one of uncertain and irregular bearing
behavior because of excessive shedding of young fruits during the
fruit-setting period and a few weeks thereafter. Moreover, it
has been noted that shedding is inversely correlated with the seed
content of the fruit. Thus, it is well established that under
conditions where the ordinary Clementine is notably capricious in
bearing behavior the seedy Monreal is regularly
productive. Recently, it has been shown that the bearing
behavior of the ordinary clone can be regularized by
cross-pollination. In descending order of effectiveness as
pollinators in Morocco, Chapot (1963a, p. 14) lists sour or
bitter orange, the Mediterranean, Dancy, and Wilking mandarins, the
lemon, and the sweet oranges, including Valencia. Soost
(1963) recommends the use of Dancy and Wilking in the Coachella Valley
of California. There can scarcely be doubt, therefore, that
the safest procedure is to provide suitable cross-pollinators or grow
the Monreal clone, the fruits of which are commonly excessively seedy
and hence less marketable.
It should
be pointed out, however, that the warm, equable, coastal regions of
western Morocco enjoy climatic conditions that are normally favorable
for fruit setting and permit the production of good crops of virtually
seedless fruit. Because of the high total heat, the fruit is
exceptionally early in maturity and commands a premium in the export
markets. Moreover, even under conditions less favorable for
fruit setting, it has been shown that regularity of bearing and
increased production result from adequate nitrogenous fertilization and
efficiency in irrigation. Finally, it has been demonstrated
that bearing can often be regularized and increased by means of a
combination of girdling or ringing and light pruning—a tree management
practice distinctive to the culture of this mandarin. The
procedure recommended consists of biennual double-girdling—at full bloom
and the end of bloom, respectively—alternated with a light pruning to
stimulate the development of new shoot growth.
Application of these cultural practices has made it practicable for
Moroccan growers to establish three export categories for this
variety—seedless Clementines, Clementines (maximum of 10 seeds), and
Monreal (more than 10 seeds).
While
accurate statistics are not available, there is reason to believe that
the annual production of the Clementine in 1965 was in the neighborhood
of 3.5 million 70-lb box equivalents. Moreover, production
seems likely to increase. Morocco, where the Clementine is
virtually the only mandarin grown, is the largest producer, followed by
Algeria, Tunisia, and Spain. In California and Arizona,
plantings in 1964 were reported to be 1,403 acres. No
processing of the fruit has been reported to date.
Because this variety is monoembryonic it is especially suitable as the
seed parent for breeding purposes. Clementine is the seed
parent for a number of promising new mandarin-tangelo hybrids—Fairchild, Lee, Nova, Osceola, Page, and Robinson—recently
released by the U.S. Department of Agriculture. Clementine
is also one of the parents of the Clement tangelo and the new Fortune and Fremont mandarins.
Clementino de Nules
See under Clementine above.
Cravo (Laranja Cravo)
Fruit medium to medium-large, slightly oblate or broadly obovate to
subglobose, with moderately rough, rather loosely adherent rind of
medium thickness and deep orange color. Segments about 10,
loosely adherent; axis large and hollow. Flesh color deep
orange; tender and melting; very juicy; flavor mild. Seeds
few to medium in number and cotyledons light green. Very
early maturity (in advance of Clementine). Retains quality
exceptionally well when stored on tree and puffs very little.
Tree vigorous and large, upright in growth habit, but spreading under
weight of crop; typical broadly lanceolate mandarin
leaves. Considerable tendency to alternate bearing with heavy
crop of smaller fruit followed by a smaller crop of larger fruit.
The Cravo is grown principally in São Paulo State of Brazil, where
currently it constitutes about 10 per cent of the
acreage. The origin and history of this interesting variety
are not known. While it may be of local origin, the
possibility exists that it was introduced from Portugal, since the
descriptions of Cravo and Carvalhais correspond fairly well.
Cravo Tardia
See under Ponkan.
Dancy (Dancy Tangerine) (fig. 4-42)
Fruit medium in size, oblate to broadly obovoid or pyriform (from
development of neck); base generally slightly but sometimes markedly
necked; apex broadly depressed. Rind thin, leathery, and
tough; loose and easily removed, but not puffy until well past maturity;
surface smooth and glossy, becoming bumpy with age; color deep
orange-red to scarlet it maturity. Segments about 12, easily
separable; axis large and hollow. Flesh deep orange-colored;
tender and melting; moderately juicy: flavor rich and sprightly (acidity
moderately high). Seeds few to medium, small, highly
polyembryonic, and cotyledons light green. Midseason in
maturity. Loses quality rapidly and rind puffs badly if held
on tree much after maturity, but stores moderately well.
Tree vigorous and large (for the mandarins), upright-spreading in
habit; nearly thornless; foliage moderately dense and of the mandarin
type, but venation not so pronounced as in
satsuma. Productive but with some alternate-bearing
tendency. Tree moderately cold-resistant but not the fruit.
Tanaka (1954) has placed Dancy in his species tangerina,
winch he suggests originated in India and was early taken to southern
China, where it is still extensively grown. He considers it
to be similar to if not identical with the Obenimikan of Japan, which was introduced from China several centuries ago. He believes that it is closely related to the Ladu and Keonla mandarins of India, a view with which the writer is in accord.
The history of Dancy's introduction into the United States (Florida),
where it is currently the most important mandarin variety, is somewhat
obscure. According to Ziegler and Wolfe (1961) the original
tree was a seedling in the grove of G. L. Dancy at Orange Mills,
Florida, which was planted in 1867. The parent tree was known
as the Moragne "tangierine" and was said to have been introduced from
Tangiers (Morocco) and planted at Palatka by a Major Atway, whose place
was acquired by N. H. Moragne in 1843. The first mention of
the Dancy variety is in the 1877 report of the Pomological Committee of
the Florida Fruit Growers Association, in which it was said to be
similar but slightly superior to the Moragne
tangerine. Although introduced to the industry as early as
1872, its commercial propagation was begun about 1890 by the Rolleston
Nursery at San Mateo. Within a few years, Dancy became the
leading mandarin variety, a position it has maintained ever since.
The high total heat and humidity of the Florida climate combine to
provide an adaptation for this attractive and popular fruit that is
unequalled elsewhere in the United States and is approached only in
limited areas in other parts of the world. This serves to
explain why its commercial importance is restricted primarily to
Florida. Except for the hottest interior districts, where
sunburn of exposed fruits is a hazard, fruit size is disappointingly
small. In arid or cooler climates and on most rootstocks, the
flavor is too acid for the average palate. Thus, in
California and Arizona, fruit of acceptable size and quality is produced
only in the low-elevation, desert regions.
The importance of the Dancy variety is reflected by the fact that on
several occasions in recent years the Florida crop has approximated 5.5
million 70-lb box equivalents. Dancy production in California
and Arizona in 1965 was about 250,000 boxes. Although long
since introduced into other parts of the citricultural world, for the
reasons set forth above, this variety has failed to compete successfully
with other, better adapted varieties.
In recent years approximately 70 per cent of the Florida Dancy crop has
been shipped fresh, the balance being processed for the juice—both
single-strength canned and frozen concentrate.
Of special interest is the fact that this variety has contributed to
the parentage of the principal tangelos (Minneola, Orlando, Sampson, and
Seminole), the Frua and Fortune mandarins, and the Dweet and Mency
tangors.
Frost Dancy, a nucellar
selection that originated in 1916 from a cross made by H. B. Frost at
the Citrus Research Center, Riverside, California, is currently the
clone most propagated in the southwestern United States. It
was introduced commercially in 1952. The Trimble and Weshart,
which came from a Dancy tangerine-Parson Brown orange cross in the
early breeding work of Webber and Swingle (1905), are now regarded as
nucellar seedlings of Dancy rather than new
varieties. Neither seedling achieved commercial importance.
Ellendale (Ellendale Beauty) (fig. 4-43)
Fruit medium large to large, oblate to subglobose; base rounded or
short-necked; apex flat or slightly depressed; small navel
frequent. Rind medium-thin, smooth to faintly pebbled;
relatively adherent though peelable at maturity; color
orange-red. Segments 10 to 12, readily separable; axis solid
to semi-hollow. Flesh bright orange-colored; very juicy;
flavor rich and pleasantly subacid. Moderately seedy with
white cotyledons, and strongly monoembryonic. Late
midseason in maturity. Loses quality rapidly if left on tree
much past maturity, especially on rough lemon rootstock, but stores
well.
Tree of medium vigor, spreading,
round-topped, thornless, and productive. Cold-resistant but
subject to breakage because of weak crotches.
This Australian variety is reported (Bowman, 1956) to have originated
about 1878 as a seedling on the Ellendale property of E. A. Burgess at
Burrum, Queensland, but did not come into prominence until much more
recently. Both Bowman (1956) and R. J. Benton, former
government citrus specialist in New South Wales, consider it to be a
natural tangor and the latter has called attention to similarities with
the Temple variety as he saw it in Florida. It is sometimes
incorrectly called Fagan or Grant.
In Queensland, Australia, where it is the principal variety, Ellendale
attains maximum fruit size and excellent quality. It is
widely grown in New South Wales, however, and normally commands
premium prices because of its large size, attractive color, and good
keeping quality. It is the latest maturing of the varieties
currently grown commercially in Australia.
A selection named Hearne is said to produce fruit of somewhat larger
size and less tightly adherent rind.
Emperor (Emperor of Canton)
Fruit large, oblate; base usually with short furrowed neck; apex
flattened or slightly depressed. Rind medium-thin, firm but
fairly loosely adherent; surface moderately smooth; color
yellowish-orange to pale orange. Segments 9 to 10, readily
separable; axis hollow. Flesh color light orange; tender and
juicy; flavor pleasant. Seeds moderately numerous,
long-pointed, and polyembryonic. Early midseason in
maturity. Loses quality rapidly if stored on tree much past
maturity.
Tree moderately vigorous,
medium-sized, upright, broad-spreading, virtually thornless, and
productive.
This very old variety in
Australia is thought to have originated there as a seedling from fruit
imported from the Orient. R. J. Benton, former government
citrus specialist in New South Wales, has stated that Emperor is very
similar to if not identical with Oneco of Florida and Ponkan of
China. Of interest is the fact that this variety is still
grown in seedling orchards in the Paterson River district of coastal New
South Wales, where the trees markedly resemble those in the seedling
districts of Coorg and Assam in India. According to Bowman
(1956), Emperor is probably the leading mandarin variety in
Australia. It is also grown to a limited extent in South
Africa and northwest India.
Late
Emperor is said to have originated as a limb sport of Emperor and the
South African Empress variety is reported to be a chance seedling of
Emperor.
Encore
Fruit medium in size,
strongly oblate in form; rind thin and moderately adherent but easily
peelable; surface texture smooth; color
yellowish-orange. Core hollow and segments about
11. Flesh color deep orange; firm in texture, but tender and
juicy; flavor rich. Seeds numerous, monoembryonic, and
cotyledons usually white. Very late in maturity (fully as
late as King) and holds especially well without loss of quality or much
puffing of the rind.
Tree moderately
vigorous, upright-growing, and virtually thornless; many slender
branches; density of foliage intermediate between the
parents. Leaves resembling King, but with narrower blades and
petiole wings. Somewhat alternate bearing but productive.
This promising, late-ripening variety originated from a cross of King
and Willowleaf (Mediterranean) made by H. B. Frost at the University of
California Citrus Research Center, Riverside. Encore was
selected and introduced in 1965 by Frost's colleagues, J. W. Cameron and
R. K. Soost (Cameron, Soost, and Frost, 1965).
Fagan
See under Ellendale.
Fairchild
Fruit medium in size and moderately oblate in form; rind medium-thin,
moderately adherent but easily peelable; surface texture smooth; color
deep orange. Flesh orange-colored; firm but tender and juicy;
flavor rich and sweet. Seeds numerous, small, and
polyembryonic. Early in maturity (about like Clementine but
colors earlier).
Tree vigorous, broad-spreading with dense foliage, nearly thornless, and productive.
This exceptionally early, high quality, new variety, which was released
in 1964, originated from a cross of Clementine mandarin X Orlando
tangelo made by J. R. Furr of the U.S. Department of Agriculture at the
U.S. Date and Citrus Station, Indio, California (Furr,
1964). Fairchild is recommended for the desert areas of
California and Arizona, where it is believed it may prove superior to
Clementine. Provision for cross-pollination is suggested
until the facts in that connection have been determined.
Fewtrell (Fewtrell's Early)
Fruit medium-small to medium, subglobose to broadly obovate; base
usually rounded; apex flattened. Rind medium in thickness;
moderately adherent but easily peelable at maturity; texture and surface
more orange-like than mandarin; color orange to reddish-orange at
maturity. Segments numerous (11-14); axis
semi-hollow. Flesh orange-colored; moderately juicy; flavor
mild and not distinctive. Seeds numerous. Early in
maturity (about like Imperial).
Tree
of medium vigor, spreading and round-topped, dense, symmetrical, and
productive. Strong tendency to alternate bearing with small
fruit in "on-crop" seasons.
Fewtrell
is an old variety in New South Wales. Its history and origin
are unknown. The characteristics of the fruit indicate that
it may be a natural tangor and those of the tree suggest the possibility
that Mediterranean or Willowleaf might have been the mandarin parent.
This variety has been abandoned in the high rainfall districts of New
South Wales. It is reported as continuing to be popular in
the interior Murray River districts of that state and the states of
Victoria and South Australia, where it is said to alternate less
strongly and early maturity coupled with ease of picking and packing
have special importance.
Fortune
Fruit medium to medium-large, moderately oblate; rind medium-thin,
fairly tightly adherent but peelable; surface texture somewhat pebbled;
color reddish-orange. Flesh orange-colored; firm but tender
and juicy; flavor rich and sprightly (subacid). Seeds
numerous, of medium size, and monoembryonic. Late in maturity and fruit holds well on tree with little loss in quality.
Tree vigorous and spreading; dense canopy protects fruit against sunburn and cold; productive.
This exceptionally late, high quality, attractive new variety
originated from a Clementine X Dancy cross made by J. R. Furr (1964) of
the U.S. Department of Agriculture at the U.S. Date and Citrus Station,
Indio, California. Fortune was released in 1964 and is
recommended for the desert regions of California and
Arizona. Provision for cross-pollination is suggested until
the facts in that connection are known.
Fremont
Fruit medium in size, oblate in form; rind medium-thick and of moderate
adherence (easily peelable); surface smooth; color bright
reddish-orange. Flesh color deep orange; tender and juicy;
flavor rich and sprightly. Seeds moderately numerous, small
to medium, and about half of them monoembryonic. Early ripening (between Clementine and Dancy), but fruit retains quality exceptionally well past maturity.
Tree moderately vigorous, upright-growing, nearly thornless,
precocious, and productive, but does not shade fruit sufficiently well
to prevent some sunburn.
Fremont is
an attractive, high quality, early-ripening variety that originated from
a Clementine X Ponkan cross made by P. C. Reece of the U.S. Department
of Agriculture at the U.S. Horticultural Field Station, Orlando,
Florida. It was first fruited at Brawley, California,
selected by J. R. Furr (1964) of the U.S. Date and Citrus Station,
Indio, California, and released in 1964. Fremont is
recommended for the desert areas of California and Arizona.
Frost Dancy
See under Dancy.
Glen
See under Beauty.
Grant
See under Ellendale.
Hearne
See under Ellendale.
Imperial (Early Imperial)
Fruit medium-small to medium, oblate to broadly obovate; short basal
neck or low collar; apex depressed. Rind very thin, leathery,
smooth and glossy, with slight adherence but no puffing until mature;
color yellowish to pale orange at maturity. Segments 9 to 11,
easily separable; axis medium and hollow. Flavor pleasantly
subacid with attractive aroma. Comparatively few
seeds. Very early in maturity (about like Wase
satsuma). Loses quality if left on tree after maturity.
Tree vigorous, medium in size, upright, virtually thornless; leaves
long, slender, and taper-pointed. Some tendency to alternate
bearing.
Imperial originated about
1890 at Emu Plains, some thirty miles west of Sydney, New South Wales,
and is believed to be a chance hybrid of Mediterranean or Willowleaf, to
which it bears considerable resemblance, and some other
mandarin—possibly Emperor. Because of its early maturity,
attractive appearance, and pleasant flavor, it commands a premium in the
markets
Kara
Fruit medium-large, moderately to slightly oblate; base commonly
slightly necked and furrowed; apex flattened or depressed with visible
areolar area. Rind medium-thick, soft in texture, moderately
adherent but peels fairly well; surface slightly rough and bumpy; color
deep orange at maturity. Segments 10 to 12, separable without
difficulty; axis medium and semi-hollow. Flesh color deep
orange; tender and juicy; flavor rich, sprightly, and distinctive (tart
until very mature). Seeds polyembryonic, numerous and
cotyledons pale greenish-yellow. Very late in season of
maturity (slightly ahead of King). Retains quality if left on
tree but puffs somewhat.
Tree
moderately vigorous, spreading and round-topped; similar to satsuma but
larger and more vigorous; thornless, with rather stout, spreading and
drooping branches; leaves dark green and satsuma-like. Hardy
to cold and productive. Slight tendency to alternate bearing.
This very late ripening and richly
flavored variety is an Owari satsuma-King mandarin hybrid created in
1915 by H. B. Frost (1935) of the University of California Citrus
Research Center, Riverside, and named and introduced in
1935. Though outstanding in flavor, Kara has not achieved
commercial importance, presumably because of the competition provided by
oranges at its season of maturity, and its seediness.
Kinnow (fig. 4-44)
Fruit medium in size, moderately to slightly oblate; both base and apex
flattened or slightly depressed. Rind thin, rather adherent
for a mandarin but peelable, tough and leathery; surface very smooth and
glossy, sometimes faintly pitted; color yellowish-orange at
maturity. Segments 9 to 10, firm, separating fairly easily;
axis solid to semi-hollow. Flesh color deep yellowish-orange;
very juicy; flavor rich, aromatic, and distinctive. Seeds
numerous, polyembryonic, and cotyledons pale
greenish-yellow. Midseason in maturity (about like
Dancy). Fruit holds well on tree with little puffing.
Tree vigorous and large, tall and columnar, with numerous long,
slender, ascending, and virtually thornless branchlets; dense foliage
consists of medium-large, broadly lanceolate leaves. Rather
strong tendency to alternate bearing with large crop of smaller fruits
followed by very small crop of larger fruits. Cold-resistant.
This high-quality variety is a sister to Wilking, both resulting from a
King-Willowleaf (Mediterranean) mandarin cross made in 1915 by H. B.
Frost (1935) of the University of California Citrus Research Center,
Riverside, California, and named and released in 1935. Kinnow
has been distributed widely and is currently grown commercially to some
extent in California, Arizona, West Pakistan, and India
(Punjab). The total plantings in California (mainly the
Coachella Valley) and Arizona in 1964 were estimated at 900 acres.
Kosho Tankan
See under Tankan.
Laranja Cravo
See under Cravo.
Lee
Fruit medium in size,
slightly oblate to subglobose; basal area slightly raised and furrowed;
apex evenly rounded or slightly flattened. Rind thin,
leathery, moderately adherent but readily peelable; surface smooth and
glossy: color deep yellowish-orange at maturity. Segments 9
to 10, readily separable; axis large and hollow. Flesh color
orange; tender and melting; juice abundant; flavor rich and
sweet. Seeds numerous and cotyledons light green. Medium-early in maturity.
Tree not distinctive, nearly thornless; dense foliage comprised of
medium-sized, lanceolate leaves.
This
new early hybrid variety is one of three (Lee, Osceola, Robinson)
resulting from a cross of Clementine mandarin X Orlando tangelo made by
Gardner and Bellows of the U.S. Department of Agriculture in Florida in
1942 and released in 1959 (Reece and Gardner, 1959). Lee is
currently under commercial trial in Florida. Since the parent
varieties respond to cross-pollination, it seems likely that the
daughter varieties will respond similarly.
Monreal
See under Clementine.
Murcott (Murcott Honey, Smith) (fig. 4-45)
Fruit medium in size, firm, oblate to subglobose; shallowly ribbed to
conform with segments; both base and apex flattened or slightly
depressed. Rind thin, rather tightly adherent and not readily
peelable; surface smooth to slightly pebbled; color yellowish-orange at
maturity. Segments 11 to 12, moderately adherent; axis
medium-large and semi-hollow. Flesh orange-colored; tender,
very juicy; flavor very rich and sprightly. Seeds small, few
to numerous, and cotyledons white. Medium-late in
maturity. Holds only moderately well on tree with some
granulation but does not puff. Ships exceptionally well.
Tree medium in vigor and size, upright-growing with long, willowy
branches; leaves medium-small, lanceolate, and
sharp-pointed. Fruit mainly borne terminally and hence
exposed to wind, frost, and sunburn injury. Productive but
with tendency to alternate bearing and one of the most sensitive
mandarins to cold.
To avoid confusion with the hybrid Honey mandarin variety of California origin, the name Honey
should not be used for this variety even as an
appendage. Likewise, the name Smith should be dropped since
Murcott clearly has priority.
The
origin of Murcott is unknown and its history obscure. The
oldest known budded tree, from which the present commercial acreage
largely if not entirely traces, still remains on the place formerly
owned by a nurseryman, Charles Murcott Smith, in Bayview, Clearwater,
Florida, and is thought to have been budded about 1922 (Ziegler and
Wolfe, 1961). It is believed that the budwood was obtained
from a neighbor, R. D. Hoyt of Safety Harbor, who was a cooperator in
the citrus breeding program of the U.S. Department of Agriculture, which
maintained a nursery of citrus hybrids at Little River, Miami, until
about 1916. Evidently the parent tree was one of the hybrids
which Mr. Hoyt received from the Department of Agriculture nursery at
Miami sometime prior to 1916. Unfortunately, records are not
available concerning this transaction or the labels for the trees
provided. Under the name Honey Murcott, small-scale
commercial propagation was undertaken by the Indian Rocks Nursery in
1928. The first commercial planting, which brought this
variety to prominence and is largely responsible for its present
popularity, seems to have been that of J. Ward Smith (no relation to C.
Murcott Smith), near Brooksville in 1944, who first marketed the fruit
under the name Smith tangerine, apparently unaware that it had already
been named.
It is the consensus of
Florida horticulturists that this variety is a tangor of unknown origin
resulting from the breeding program of the U.S. Department of
Agriculture.
During the past decade,
Murcott has been planted rather extensively, in Florida. The
1961 plantings, mostly nonbearing, were reported at 5,400 acres and the
1961-62 crop at approximately 175,000 boxes (70-lb
equivalents). Because of its rich flavor and deep
orange-colored flesh and juice, Murcott is a favorite with gift fruit
packers.
Nagpur
See under Ponkan.
Nova
Fruit much like Orlando in size and form, medium-large, oblate to
subglobose and without neck; base slightly rounded; apex nearly
flat. Rind thin, leathery, moderately adherent but easily
peelable; surface slightly pebbled; color deep yellowish-orange at
maturity (deeper than Orlando). Segments about 11, easily
separable; central axis medium in size and open. Flesh color
deep orange; juicy; flavor pleasant. Seeds numerous in mixed
plantings, polyembryonic, and with light green
cotyledons. Colors and matures very early (considerably ahead
of Orlando).
This very early ripening
variety is a sister to the Lee, Osceola, and Robinson mandarins, all
four resulting from a Clementine mandarin-Orlando tangelo cross made in
1942 by Gardner and Bellows of the U.S. Department of Agriculture at
Orlando, Florida, and described and released in 1964 (Reece, Hearn, and
Gardner, 1964). Since its parents are strongly
self-incompatible and more fruitful if cross-pollinated, it seems likely
that Nova will exhibit the same characteristics.
Oneco
See under Ponkan.
Ortanique (fig. 4-46)
Fruit large (very large for mandarin), very broadly obovoid to slightly
oblate to almost subglobose; base evenly rounded or tapering to low,
shallowly furrowed neck or collar; apex flattened or with shallow
depression and sometimes with small protruding navel; areole evident
though not prominent. Rind thin, leathery, rather tightly
adherent but peelable; surface smooth but finely pitted, glossy; color
bright yellowish-orange at maturity. Segments
10 to 12; axis solid to semi-open. Flesh orange-colored;
juicy; flavor rich and distinctive. Seeds average about 10,
plump, with white cotyledons, and polyembryonic. Late
midseason in maturity and holds well on tree.
Tree moderately vigorous, medium-large, spreading and drooping, almost
thornless, with slender branchlets; dense foliage consists of
medium-sized leaves with narrowly winged petioles.
The origin of this attractive and promising variety is unknown, but
Ortanique is reported (Anonymous, 1963) to be an old chance seedling
that came to the attention of C. P. Jackson of Chellaston, Mandeville,
Jamaica, in 1920. He is said to have grown 130 seedlings from
it, of which about 40 per cent resembled the parent fruits, and to have
selected those which he considered best.
Because of the presence of wild orange and so-called tangerine trees in
the vicinity of the original tree and the distinctive features of the
fruit, it was considered to be a natural tangor and was given the name
Ortanique by H. H. Cousins, a former Director of
Agriculture. The name was a synthesis coined from or(ange),
tan(gerine), and (un)ique. The present clone probably
represents a nucellar seedling of the parent tree. It is
worth noting that two other high quality, mandarin-like varieties—Temple
and Ugli—are believed to have originated as wild chance seedlings in
Jamaica.
Although Ortanique early
gained popularity in the local markets, it was not planted much until
comparatively recently when small shipments to Canada and Great Britain
received favorable market reactions and brought high
prices. Acreage was said to be approximately 2,000 in 1964
when about 1,200 acres were six years old or less. The
Jamaica Citrus Growers' Association reported that its handlings
increased from 22,246 field boxes in 1960-61 to 73,616 boxes in 1962-63
and were expected to reach 250,000 boxes by 1967.
Osceola
Fruit medium in size, medium-oblate in form; base flattened and
sometimes slightly corrugated; apex flattened or slightly
depressed. Rind thin, leathery, moderately adherent but
easily peelable; surface smooth and glossy; color deep orange to almost
coral-red at maturity. Segments 10 to 11, easily separable;
axis large and hollow. Flesh color deep orange; juicy; flavor
rich and distinctive. Seeds numerous and cotyledons very
pale green. Medium-early in maturity.
Tree not distinctive, virtually thornless, more upright than
Clementine; dense foliage composed of medium-sized lanceolate leaves.
This exceptionally high-colored, early variety is a sister to Lee and
Robinson, all three resulting from a Clementine mandarin-Orlando tangelo
cross made by Gardner and Bellows of the U.S. Department of Agriculture
in Florida in 1942 and released in 1959 (Reece and Gardner,
1959). Osceola is currently under commercial trial in
Florida. It seems likely that it will respond to
cross-pollination since both parent varieties are strongly self
-incompatible and more fruitful when seedy.
Page
Fruit of medium size, broadly oblate to subglobose; apex evenly
rounded. Rind medium-thin, leathery, moderately adherent but
easily peelable, surface smooth to moderately pebbled; color
reddish-orange at maturity. Segments about 10 and central
axis solid to slightly open. Flesh color deep orange; tender
and juicy; flavor rich and sweet. Seeds moderately numerous
and cotyledons pale yellow to almost white. Early in
maturity.
Tree moderately vigorous;
branches upright, spreading under the weight of fruit, nearly thornless;
productive.
This early ripening, high
quality variety, the fruit of which has considerable resemblance to a
sweet orange, originated from a Minneola tangelo X Clementine mandarin
cross made by Gardner and Bellows of the U.S. Department of Agriculture
in 1942. Page was described and released in 1963 by P. C.
Reece and F. E. Gardner at the U.S. Horticultural Field Station,
Orlando, Florida. It is recommended for Florida conditions
and the fruit may be undesirably small in arid
climates. Cross-pollination should be provided until the
facts in that connection have been determined.
While officially released as an orange, technically speaking this
variety should probably be referred to the tangelo hybrid group, since
its parentage is three-fourths mandarin and one-fourth grapefruit.
Ponkan (Nagpur, Warnurco) (fig. 4-47)
Fruit large (for a mandarin), globose to moderately oblate; base commonly with strong furrowed but relatively short neck or low collar;
apex usually deeply depressed and with radiating furrows; sometimes
with naval. Rind medium-thick, fairly loosely adherent;
surface relatively smooth but pebbled, with prominent, sunken oil
glands; orange-colored at maturity. Segments about 10, easily
separable; axis large and hollow. Flesh color orange; tender
and melting, juicy; flavor mild and pleasant, and
aromatic. Seeds few, small, plump, and polyembryonic;
cotyledons light green. Early midseason in
maturity. Loses quality and rind puffs if not picked when
ripe.
Tree commonly vigorous and
distinctive in appearance because of pronounced upright growth
habit. Productive but with strong alternate-bearing
tendency. Reported to be less cold-resistant than most
mandarins.
This is the famous and highly reputed ponkan of South China and Formosa, the Batangas mandarin of the Philippines, and the Nagpur suntara or santra (various other spellings) of India. Other names that occur in the literature and should best be dropped include Swatow orange and Chinese Honey orange.
Tanaka (1927) is of the opinion that this mandarin originated in India
and because of its excellence spread widely throughout the Orient at an
early date. This view finds support in the fact that for
centuries it has been cultivated in the form of seedling groves in
widely separated parts of India—notably in the Coorg district in the
south and Assam and neighboring Nepal and Sikkim in the northeastern
portion of that country. As previously noted, there is reason
for believing that this fruit reached Europe as early as
1805. The first known introduction into the United States,
however, is referred to 1892 or 1893 when an American medical missionary
in China sent fruits to J. C. Barrington of McMeekin, Florida, from
which seedlings were grown. One of these was later identified
as Ponkan (Tanaka, 1929a). Prior to this
identification, however, the Wartmann Nursery Company at Ocala had
propagated this fruit on a limited scale under the name Warnurco
tangerine. More recent introductions have been made by the
U.S. Department of Agriculture.
Because of its highly distinctive characteristics and his conclusion
that the Batangas mandarin was the fruit described by Blanco under the
species name reticulata, Tanaka (1954) restricted this species to
the Ponkan group, a view which in the judgment of the writer has
considerable merit, although it has not been generally
accepted. Several forms or clones are recognized of which
that characterized above and known in India as Nagpur suntara is clearly
superior. Almost certainly the highly important seedling
varieties known variously as Coorg, Assam, Khasi, Butwal, and Sikkim in
India are nucellar clonal budlines of the Nagpur suntara. In
this connection, it may be of interest to note that the variety Oneco,
which originated in Florida from seed received by P. W. Reasoner in 1888
from northwestern India, has been identified as a form of ponkan
(Tanaka, 1929a). Oneco differs, however, in that the
fruit is rougher and seedier, ripens somewhat later, and retains its
quality on the tree much better, although the rind puffs rather
badly. Oneco has never achieved commercial importance and is
grown primarily as a home and gift-box fruit. Oneco appears
to be the Cravo Tardia of Brazil.
The
Nagpur suntara is the citrus fruit of greatest commercial importance in
India. While accurate statistics are not available, it is
believed that the total plantings of this variety and its seedling
derivatives are in the neighborhood of 100,000 acres. The
modern commercial industry based on the use of budded trees centers in
the Nagpur region of central India, where a small but growing processing
industry has developed. Elsewhere this fruit has importance
in Ceylon, Indonesia, Malaysia, the Philippines, South China, Taiwan,
and the southern part of Kyushu Island, Japan. It is of
limited importance in Brazil and very minor importance in Florida.
Climatically, the ponkan is one of the most tropical
mandarins. Under tropical conditions the fruit attains
maximum size and quality and finds little competition from other
mandarins. In the hot arid subtropics, however, it has
generally proven disappointing and other varieties are better adapted
and more popular.
Much the most
unusual and distinctive cultural practice is that followed in central
India, where the growers select and accentuate one of the three periods
of bloom characteristic of the mandarin tree there to control the time
of maturity and increase the resultant crop. This is
accomplished by what is commonly referred to as the "resting treatment"
(Gandhi, 1956, pp. 32-35). In reality, it is a combination of
treatments that place the trees under severe moisture stress from which
they are released either by irrigation or the advent of the summer
monsoon rains. The practice is similar to that employed by
Sicilian lemon growers to accentuate the early fall bloom and increase
the summer or verdelli crops. The differences in the characteristics of the fruit from the spring and fall blooms are remarkable.
Another distinctive practice has already been mentioned, namely, the
exclusive use of unbudded seedling trees in the important Coorg and
Assam regions. The resulting orchards are remarkably uniform,
and the trees extremely tall and slender.
Robinson
Fruit medium-large, oblate (more so than Osceola): base evenly rounded
or slightly necked; apex broadly depressed. Rind thin, tough
and leathery, moderately adherent but easily peelable: surface smooth
and glossy; color deep yellowish-orange at maturity. Segments
numerous (12-14), readily separable; axis large and
hollow. Flesh color deep orange; juicy; flavor rich and
sweet. Seeds moderately numerous and cotyledons light
green. Early in maturity (about the same as Lee and Osceola
but colors earlier).
Tree
upright-spreading, nearly thornless; dense foliage consists of large
broadly lanceolate, taper-pointed leaves, commonly notched at the tip
and crenate-margined on the upper half. Appears to be a
regular bearer.
This very early
maturing, rather large-fruited variety is a sister to Lee and Osceola,
all three resulting from a Clementine mandarin-Orlando tangelo cross
made by Gardner and Bellows of the U.S. Department of Agriculture in
Florida in 1942 and released in 1959 (Reece and Gardner,
1959). Robinson is currently under commercial trial in
Florida. Since its parents are both self-incompatible and
more fruitful if cross-pollinated, it seems likely that Robinson will
exhibit the same characteristics.
Smith
See under Murcott.
Tankan
Fruit medium-large to large, subglobose to broadly pyriform (from
development of neck); base rounded or with more or less prominent and
furrowed neck; apex slightly rounded or flattened. Rind
medium-thick (for mandarin), moderately adherent but readily peelable;
surface pebbled and commonly somewhat wrinkled; deep orange-colored at
maturity. Segments about 10, readily separable: axis
semi-hollow. Flesh deep orange; tender, very juicy; flavor
rich and sweet. Seeds few to many. Medium-late in
maturity. Retains quality when held on tree and ships and
stores well.
Tree of medium vigor and
size, upright, virtually thornless; leaves medium-large, broadly
lanceolate, and taper-pointed, with midribs strongly prominent above and
petioles margined to narrowly winged. Productive.
According to Tanaka (1929b),
the Tankan is a very old variety that originated in southeastern China
and early spread to Formosa and Japan, where its culture is confined to
the hotter portions of Kagoshima Prefecture. Tanaka considers
it to be one of the finest citrus fruits of the
Orient. While the tree characters are almost entirely
mandarin, the fruit exhibits certain features which suggest the
possibility that it is a natural tangor. It is classified by
Tanaka (1954) as C. tankan Hayata.
Kosho Tankan is a Formosan derivative that is characterized by fruit of larger size, superior quality, and later maturity.
Trimble
See under Dancy.
Warnurco
See under Ponkan.
Weshart
See under Dancy.
Wilking
Fruit small to medium in size, slightly oblate; base flattened and
somewhat furrowed; apex flattened or moderately
depressed. Rind medium-thin, somewhat brittle, somewhat
adherent but readily peelable; surface slightly pebbled, glossy.;
orange-colored at maturity. Segments 9 to 12, firm but
separating easily; axis semi-hollow. Flesh color deep orange;
very juicy; flavor rich, sprightly, aromatic, and
distinctive. Seeds moderately numerous, monoembryonic,
and cotyledons greenish-yellow to yellow-tinged. Midseason
in maturity (about like Kinnow). Retains quality and stores
well on tree but with some puffing.
Tree moderately vigorous, medium in size, round-topped, nearly
thornless; leaves long, broadly lanceolate, and
taper-pointed. Strong tendency to alternate bearing with
small fruits in the on-crop seasons and little or no fruits in the
off-crop years. Cold-resistant.
A sister to Kinnow, both resulting from a cross of King X Willowleaf
(Mediterranean) made in 1915 by H. B. Frost (1935) of the University of
California Citrus Research Center, Riverside, this richly flavored
variety has been widely distributed, but with minor exceptions has not
achieved commercial importance. Wilking is reported to have
done well commercially, however, in the Souss Valley of Morocco and is
considered promising in Brazil.
Minor Common Mandarin Varieties.—The
common mandarins discussed in the subsection below are of lesser
commercial importance, local interest, or still have not proven
themselves.
Burgess (Solid Scarlet)
This Australian variety produces a late-ripening, relatively
tight-skinned fruit much like Ellendale but somewhat deeper in
color. It originated in 1908 as a seedling of Ellendale grown
by E. A. Burgess at Burrum, Queensland. Burgess is not
related to Scarlet and is declining in importance.
Capurro
Fruit medium-large, strongly oblate; orange-colored;
seedy. Relatively loose rind of medium
thickness. Numerous slightly adherent
segments. Abundant juice; flavor rich and somewhat
tart. Cotyledons green. Early maturity.
Tree vigorous and large with numerous fine, nearly thornless
branchlets; moderately dense foliage composed of long, lanceolate,
taper-pointed leaves.
This Argentinian
variety is reported to have originated fairly recently as a chance
seedling in the Capurro orchard in Colonia Yerua, near Concordia, Entre
Ríos Province. Capurro is of minor but growing importance in
Argentina.
Carvalhais (Tangera) (fig. 4-48)
Fruit medium to medium-large, oblate to almost globose; basal area
somewhat furrowed and commonly short necked; apex rather deeply
depressed, usually with prominent areolar area and ring. Rind
medium-thick, tough, rather strongly adherent; orange when fully
colored. Flesh juicy and pleasantly subacid early in season,
but loses quality thereafter. Seeds numerous and highly
polyembryonic. Maturity very early (fully as early as
Clementine), occurring much in advance of rind color
development. Fruit holds well on tree with little puffing.
Tree vigorous, upright in habit; leaves distinctive, long, and
sharp-pointed, somewhat resembling the Clementine.
Carvalhais is of unknown but almost certainly local Portuguese
origin. It is thought to be a natural hybrid of which one
parent is the Mediterranean mandarin, known locally as
Setubalense. Carvalhais has commercial importance in Portugal
and is exported to a small extent to nearby countries—particularly
Morocco and Algeria.
Empress
Fruit similar to Emperor but averages smaller, is somewhat seedier, and
seeds are said to be more highly polyembryonic. Also stores
better on the tree, which is more vigorous and upright in growth.
Empress originated as a chance South African seedling, believed to be
of Emperor, in the Watkinson Nurseries at Nelspruit, eastern
Transvaal. It was selected by R. H. Marloth of the Citrus and
Subtropical Fruit Research Institute at Nelspruit about
1932. Although the fruit is popular in the local markets,
this variety is of primary interest in South Africa as a rootstock.
Frua
Fruit medium-sized, slightly necked, somewhat
pebbled. Reddish-orange with few seeds and mild, sweet
flavor. Rind puffs rather badly. Early midseason
in maturity (earlier than Dancy, which it somewhat
resembles). Tree lacks vigor.
Frua is a hybrid of the King mandarin with the Dancy tangerine
developed from a cross made by H. B. Frost of the University of
California Citrus Research Center, Riverside. It was selected
in 1925 and released in 1950.
Hansen
Hansen is a late variety that follows Ellendale, which is currently
under trial in South Australia. It may be a tangor.
Hickson
This midseason Australian variety originated in Queensland, where it is
currently under trial. Hickson may be a tangor.
Honey
Fruit small-sized, oblate; rind faintly pebbled; seeds
numerous. Light yellowish-orange; flavor rich and
sweet. Matures early. Tree vigorous and tends
strongly to alternate bearing.
Honey
is a hybrid of the King mandarin with the Willowleaf (Mediterranean)
mandarin made by H. B. Frost of the University of California Citrus
Research Center, Riverside. This hybrid is a sister of
Encore, Kinnow, and Wilking. It was described in 1943 but
never released officially.
Kaula (Keonla)
Kaula is a highly colored, strongly oblate, short-necked, and apically
depressed fruit of medium size and good flavor.
Kuala is of Indian origin and local importance only. Tanaka
has classified this fruit as C. crenatifolia Lush.
Keonla
See under Kaula above.
Ladoo
See under Ladu below.
Ladu (Ladoo)
This Indian variety produces an attractive, reddish-orange, nearly
seedless, slightly necked, oblate fruit of medium size and good
flavor. The tree is vigorous, dense, round-topped, and
productive.
Ladu is of unknown but
presumably Indian origin. Gandhi (1956) reports that it has
commercial importance in Uttar Pradesh and parts of the
Deccan. Tanaka (1954) classified this fruit as C. paratangerina Hort. ex Tan.
Late Emperor
This Australian variety is indistinguishable from Emperor, but the
fruit matures about a month later. It is said to be a limb
sport of the Emperor variety.
Malvasio
Fruit medium in size, oblate to subglobose; neck short and furrowed;
often with small navel; moderately seedy. Rind
orange-colored, thin, relatively adherent but peelable; about 10
moderately adherent segments; semi-hollow axis. Good juice
content and pleasant subacid flavor. Cotyledons light
green. Maturity very late. Holds well on tree and
stores well.
Tree vigorous, large,
and broad-spreading with some strong and distinctive horizontal
branches. Leaves of medium size, lanceolate with apex blunt
and notched.
This Argentine variety
was found in an orchard (details not available) near Concordia, Entre
Ríos Province, and is believed to have originated as a chance seedling.
Mandalina
This Lebanese variety closely resembles Dancy and produces an
attractive, reddish-orange, seedy, loose-skin fruit of midseason
maturity and mediocre quality. The rind puffs
badly. Mandalina is of little importance and apparently an
old variety of unknown origin.
Muscio
This Australian variety produces a very late-ripening fruit of good
size and quality. It is strongly alternate bearing, however.
Naartje
Fruit medium to medium-large, firm, and moderately
seedy. Strong rind adherence (though
peelable). Color orange to orange-red and flavor
rich. Midseason maturity. Good shipping quality.
Tree of medium vigor and size, spreading, round-topped, and virtually
thornless; fairly dense foliage consisting of large, dark-green leaves.
Of unknown Oriental origin, Dutch traders early introduced a
distinctive type of mandarin to South Africa, which was given the name naartje, presumably by the Boer settlers.
Until comparatively recently propagation was by means of seedlings,
which exhibit remarkably little variation, apparently because the seeds
are highly polyembryonic. The principal named clonal
varieties currently are Natal Tightskin and Redskin, the latter being
characterized by somewhat deeper rind color. It is said to
closely resemble the Australian variety Beauty.
Natal Tightskin
See under Naartje above.
Parker (Parker Special)
The fruit of this midseason Australian variety is large,
reddish-orange, and attractive, but the flesh is poorly
flavored. The tree is of good bearing behavior.
Pixie
Fruit small to medium-small, subglobose to round; commonly with broad,
short neck and collar. Rind medium-thin, easily separable;
grained to pebbled surface texture; color
yellowish-orange. Flesh medium-orange; moderately juicy;
flavor pleasant and mild. Virtually seedless (occasionally 1
seed). Holds well on tree with little rind-puffing, but some
juice loss. Matures late.
Tree vigorous, erect to somewhat spreading; stout, ascending branches
and large, King-like leaves. Tendency to alternate
bearing. Considerable proportion of inside fruits not subject
to sunburn.
Pixie is a second
generation seedling (hybrid or self) from open pollination of a cross of
King and Dancy (named Kincy). This variety was made in 1927
by H. B. Frost of the University of California Citrus Research Center,
Riverside, and was selected and introduced in 1965 by his colleagues J.
W. Cameron and R. K. Soost. Because of its seedlessness and
lateness of maturity, Pixie may have promise, especially as a home
orchard variety (Cameron, Soost, and Frost, 1965).
Redskin
See under Naartje.
Sanguigno (Sanguine in North Africa)
This Italian variety of unknown origin produces an attractive
medium-sized, seedy, deep reddish-orange fruit of midseason maturity and
indifferent quality. The fruit puffs badly and keeps
poorly. Both tree and fruit markedly resemble the Scarlet
variety of Australia.
The name is a
misnomer, for this variety is not a true blood
mandarin. Indeed, the writer does not know of any pigmented
true mandarins.
Scarlet
Scarlet is an old Australian variety no longer grown
commercially. It produces a medium-sized, seedy,
reddish-orange fruit of early midseason maturity that puffs excessively,
and keeps poorly. The tree is productive.
Solid Scarlet
See under Burgess.
Som-Chuk (Somjook, Necked Orange)
Fruit large, round to obovate, with prominent neck. Rind
medium-thick and readily peelable. Easily separable segments
and open center. Flesh juicy and of rich subacid
flavor. Tree vigorous, upright, and thorny.
This highly reputed mandarin, the so-called necked orange, is possibly a
natural tangor. Som-Chuk is an old variety of unknown origin
that is grown mainly in the southern peninsular area of Thailand, where
it is propagated by seed only. The descriptions and
illustrations available (Wahlberg, 1958, and personal communication)
suggest close resemblance to the Ponkan.16
Somjook
See under Som-Chuk, above.
Stemp
This midseason Australian variety originated in Queensland, where it is
currently under trial. Stemp is much like Hickson and may be
a tangor.
Wallent
Fruit medium-small, reddish-orange, and of attractive
appearance. Rind thin and relatively
tight-skinned. Distinctive, sprightly
flavor. Colors early, but remains too acid for many palates
until late midseason. Tree strongly alternate in bearing
behavior.
Wallent originated as a
chance seedling in a home garden in Adelaide, South Australia, and was
introduced by a Mr. Wallent of Wambaral, Gosford, New South
Wales. It was popular locally for some time but has been
little planted in recent years.
Small-fruited Mandarins
Groups IV and V of the Tanaka (1954) classification contain a total of
sixteen species and are characterized by small flowers, fruits, and
leaves. The leaves are narrow in Group IV and broad in Group
V. Of these species the writer has seen eleven but possesses
some degree of competence for only three. Some of these
Citrus species may be subject to question, but those with which the
writer is acquainted—indica, tachibana, and reshni—appear to constitute valid species. Currently seven species are of horticultural importance or promise:
1. Citrus amblycarpa Ochse—This is the djerook leemo of
Java. The tree is highly distinctive. The fruit
is very small, tight-skinned, yellow, and very acid, with polyembryonic
seeds and green cotyledons. The species is experimentally
promising as a rootstock in California.
2. Citrus depressa Hayata (formerly C. pectinifera Tan.)—This species is the shiikuwashâ of Okinawa and Taiwan and shekwasha or sequasse
in collections in the United States. The tree is vigorous,
round-topped, and finely stemmed. The fruit is very small,
orange-colored, oblate, and highly depressed at both ends, with very
thin, loose, and aromatic rind. The flesh is soft,
gelatinous, and acid, but ultimately attains a rich
flavor. The seeds are polyembryonic with green
cotyledons. The tree makes an attractive ornamental.
3. Citrus kinokuni Hort. ex Tan.—This species is the kishû mikan
of Japan. The fruit is small, somewhat oblate, depressed at
both ends, orange-colored, and glossy. The thin,
comparatively tight rind is easily peelable and fragrantly
aromatic. The flesh is firm, meaty, and pleasantly sweet in
flavor. Seeds are few, polyembryonic, and have pale green
cotyledons. Fruit maturity occurs in early midseason.
The kinokuni
is said to be a very old species of Chinese origin and one of the
earliest introduced into Japan, where it is still popular because of its
pleasant flavor and rich fragrances Tanaka (1954, p. 136) states that
at least four varieties are known, the largest of which is Hirakishu (fig. 4-49). Mukakukishu is a completely seedless variety.
4. Citrus lycopersicaeformis Hort. ex Tan.—This species is the kokni or kodakithuli of
southern India. The fruit is very small, moderately oblate
to obconical, deep orange, and has a thin, moderately loose
rind. The flesh is somewhat coarse-grained, dry, and acid but
becomes edible at full maturity. Seeds are polyembryonic
with green cotyledons.
This species
is considered to be native to India and can be found in markets
there. Tanaka (1954, p. 140) reports that the heennaran of Ceylon is identical.
5. Citrus oleocarpa Hort. ex Tan.—This species is the timkat of southern China and yuhikitsu of
Japan. The fruit is small, yellowish-orange, and somewhat
oblate. The base usually has a short radially furrowed neck
and the apex is depressed. The rind is medium-thin,
relatively tight but readily peelable, and strongly
aromatic. Flesh color is deeper than that of the rind, the
texture is crisp, and the flavor is rich but subacid. The
seeds have light green cotyledons.
This species is of Chinese origin and is said to have importance on the
Chinese mainland, on Hong Kong Island, and on Taiwan.
6. Citrus reshni Hort. ex Tan. (fig. 4-50)—This species is the chota or billi kichili
of India and the Cleopatra mandarin of the United
States. The tree is attractive, round-topped, symmetrical,
and thornless, with small, dark-green leaves. The fruit is
orange-red, small, oblate, and highly depressed at the apex, with thin,
somewhat rough rind. The flesh texture is soft and juicy and
the flavor is somewhat acid. Seeds are small, polyembryonic,
and have green cotyledons.
Considered
to be native to India and said to have been introduced into Florida
from Jamaica sometime prior to 1888, C. reshni is increasingly
important as a rootstock in the United States and
elsewhere. It is an attractive ornamental and bears fruit the
year round.
7. Citrus sunki Hort. ex Tan.—The sunki, suenkat or sunkat of South China, which is the sour mandarin (C. reticulate, var. austere) of Swingle's classification (see chap. 3, this work),
is a medium-small, upright tree with distinctive pale-green
leaves. The fruit is medium-small, oblate and markedly
depressed at both ends, and with basal furrows. The ring [sic]
is very thin, loose, and light yellowish-orange, with a smooth, shiny
surface and prominent oil glands. The rind is strong and
spicy with a distinctive aroma. The flavor is acid, the fruit
never becoming edible. Seeds are medium-large, plump,
polyembryonic, and have pale-green cotyledons.
C. sunki is considered to be native to China and is said to be a widely employed rootstock in China and Taiwan.
Fruits Most Resembling the Mandarins
Tangors.—Hybrids
of the mandarin and orange have been designated tangors (Swingle,
Robinson, Savage, 1931). The few that have been named to date
are mandarin-like in most respects and hence fall into this group.
Varieties commonly referred to as natural tangors include the King and
Clementine mandarins and the so-called Temple orange of
Florida. Others which exhibit characters that suggest the
likelihood of hybrid parentage include the Campeona, Ellendale, and
Ortanique mandarins, the so-called Murcott orange, and the
tankan. In this treatment, however, King is assigned to C. nobilis and, with the exception of Temple, the others mentioned are provisionally placed in the C. reticulata group. It
is to be noted, however, that two of them—Clementine and tankan—are
given species standing by Tanaka (1954) as are also a number of other
oriental forms such as Iyomikan which he regards as natural tangors.
Of the so-called natural tangors, Temple is much the most important
variety. While it is obviously a mandarin hybrid, in the
opinion of the writer such characteristics as seed monoembryony and
pronounced cold-sensitivity of the tree suggest that it may be a natural
tangelo of which pummelo rather than grapefruit is one of the
parents. Since the consensus is that it is a tangor, however,
it is included here.
In addition to
the natural tangors, there are several synthetic tangors, which are the
result of breeding work in California and Florida. Only one
of these—the Umatilla—has any commercial importance, the others
remaining experimental.
Dweet
Fruit medium-large, reddish-orange, globose to oblate-necked, and
moderately pebbled. Rind peels poorly and tends to
puff. Seedy, very juicy, and of rich
flavor. Matures late. Does not hold well on tree,
but good for home use.
The Dweet
tangor, currently on trial in Califomia, is of Mediterranean Sweet
orange and Dancy tangerine parentage. This synthetic tangor
resulted from the breeding experiments of H. B. Frost of the University
of California Citrus Research Center, Riverside. It was
selected in 1930 and introduced in 1950.
Mency
Fruit medium-small, reddish-orange, slightly oblate and necked, and
faintly pebbled. Rind peels readily. Seedy, early
ripening fruit of sprightly, acid flavor. Sensitive to
sunburn and does not hold well on tree, but good for home use.
This synthetic tangor resulted from breeding work by H. B. Frost of the
University of California Citrus Research Center,
Riverside. It is of Dancy tangerine and Mediterranean Sweet
orange parentage, in which respect it is reciprocal to Dweet.
Temple (fig. 4-51) [Citrus temple Hort. ex Y. Tanaka]
Fruit medium-large, very broadly obovate to slightly subglobose;
sometimes with short, wrinkled, or furrowed neck; frequently with small,
sometimes protruding navel; seedy. Rind color deep
reddish-orange; medium-thick; surface somewhat pebbled or rough, and
moderately adherent, but readily peelable. Segments 10 to 12
and axis mainly solid. Flesh orange-colored; tender,
moderately juicy; flavor rich and spicy. Seed monoembryonic. Medium-late in maturity.
Tree of medium vigor, spreading and bushy, somewhat thorny; leaves
medium-sized and mandarin-like; productive. More
cold-sensitive than any of the mandarins or oranges.
Because of its high heat requirement and sensitivity to cold and both
rootstock and soil influences, Temple is decidedly limited in its range
of commercial adaptation. In this respect, it is somewhat
similar to the King mandarin. Within its range of adaptation,
the fruit is of outstanding attractiveness and quality, but elsewhere
it is highly disappointing and commercially worthless. Temple
is at its best in Florida when propagated on sour orange or Cleopatra
mandarin rootstocks and grown on the heavier-textured
soils. Satisfactory quality in California is attained only in
the hottest of the interior districts. Elsewhere, Temple is
poorly colored and much too tart for most palates.
The origin and history of this variety are somewhat
obscure. According to Ziegler and Wolfe (1961) and Harding
(1959), it originated in Jamaica and came to the attention of a Florida
fruit buyer about 1896, who ran across a seedling tree of outstanding
quality. The buyer sent budwood to several friends at Oviedo,
Florida, who budded a few trees of this "Jamaica"
orange. About 1900, Allan Mosely, an orchard caretaker in the
Winter Park area, is said to have obtained budwood from one of the
friends, J. H. King. Mosely budded a tree in a young orchard
under his care which in 1914 came into the ownership of L. A.
Hakes. The following year Hakes called the tree to the
attention of a neighbor, W. C. Temple, former manager of the Florida
Citrus Exchange, who in turn reported its unusual qualities to his
friend and former associate, M. E. Gillett, president of Buckeye
Nurseries, a leading citrus nursery. Exclusive propagation
rights were obtained in 1916. The variety was named and
introduced in 1919 and was promoted on a large scale.
Once its limitations and adaptations became evident, Temple continued
to increase in popularity to the point where both acreage and production
now exceed that of the Dancy tangerine. The 1961 crop was
nearly 6 million 70-lb box equivalents. In recent years,
Temple has been planted to a limited extent in the Coachella Valley of
California, where total plantings were reported to be 796 acres in 1964.
Umatilla
Fruit
medium-large, reddish-orange, and broadly oblate. Moderately
seedy with smooth, medium-thick, moderately adherent rind and hollow
axis. Flesh orange-colored; tender, very juicy; flavor rich
but acid. Seeds monoembryonic and cotyledons green. Medium-late maturity.
Tree slow growing, spreading, with considerable resemblance to satsuma; productive.
Umatilla is a hybrid of satsuma mandarin and Ruby orange resulting from
a cross made in Florida in 1911. This synthetic tangor was
named and described by Swingle, Robinson, and Savage
(1931). Although described as a tangelo, from which it is
indistinguishable, its parentage is that of a tangor. It has
not achieved commercial importance except as a specialty fruit in
Florida.
Tangelos.—Webber
and Swingle (1905) designated hybrids of the mandarin and grapefruit
and pummelo as tangelos. The first crosses giving rise to
tangelos were made by these two men in 1897 in
Florida. Currently, a dozen or more tangelos have been named
and described.
As might be expected,
the tangelos constitute a highly varied group, exhibiting characters
that are both typical of the parents and intermediate between
them. In general, however, those of greatest commercial
interest or promise fall into the mandarin-like group. Some
of them produce highly colored, aromatic, distinctive, and richly
flavored fruits of good size with thin, smooth, and only moderately
loose rinds. Others exhibit such faults of some of the
mandarins as undesirably long necks, puffing of the rind, and excessive
seediness. On the whole, however, the tangelos currently
comprise much the most important and promising of the interspecific
hybrids of the genus Citrus. Several of them already
have attained commercial importance and one variety, Orlando, achieved
production in Florida of more than a million boxes in 1965.
It has recently been shown that for regular and satisfactory production
some of the tangelos require cross-pollination since they are weakly
parthenocarpic and benefit from the presence of seed, which they are
unable to produce from self-pollination. A few of them,
notably Sampson, reproduce remarkably true to seed since they are highly
polyembryonic.
There are several
fruits and varieties of unknown origin that resemble some of the
tangelos and are provisionally classified as natural
tangelos. The natural tangelo currently of greatest
importance is the Ugli of Jamaica, unless the more popular Temple
(herein classed as a natural tangor) is, in fact, a tangelo.
Treated elsewhere, since they more closely resemble the pummelo are such fruits as the Hassaku and Natsudaidai of Japan, the Attani of India, and the Poorman
of Australia. In addition, some of the synthetic hybrids
that bear a greater resemblance to the grapefruit than the mandarin-like
fruits are also discussed in a later section. Tangelo varieties of current importance, promise, or special interest are presented below.
Allspice
Fruit medium-small, slightly oblate to globose; color orange-yellow;
seedy. Rind thin, slightly pebbled, and rather tightly
adherent. Solid axis; flesh tender and juicy; rich, tart,
spicy flavor and aroma. Midseason in maturity and loses
quality if left on tree much past maturity.
Tree and foliage mandarin-like in appearance.
Allspice resulted from a cross of the Imperial grapefruit and
Willowleaf mandarin made in 1917 by H. B. Frost of the University of
California Citrus Research Center, Riverside. Although the
fruit is small, it is attractive because of its rich flavor and spicy
fragrance.
Broward
Broward is a medium-large, midseason fruit of good
quality. It is a hybrid of Duncan grapefruit and Dancy
tangerine that was selected in 1912 and released in 1939. It
has never achieved commercial importance.
Clement
Fruit medium-large, subglobose to slightly oblong; color light
orange-yellow. Few-seeded (monoembryonic); rind
pebbled, somewhat wrinkled, comparatively thick, and easily
peeled. Flesh color dull yellow; soft, somewhat gelatinous;
flavor mildly sweet. Medium-early in maturity.
Tree productive.
Clement is a hybrid of the Duncan grapefruit and Clementine mandarin
produced in Florida in 1914 by W. T. Swingle of the U.S. Department of
Agriculture and introduced in 1931. It has not attained
commercial importance.
K-Early
This variety more closely resembles the grapefruits and pummelos.
Minneola (fig. 4-52)
Fruit large, oblate to obovate; neck usually fairly prominent; seeds
comparatively few, with greenish cotyledons. Rind color deep
reddish-orange; medium-thin, with smooth, finely pitted surface, and
moderately adherent (not loose-skin). Segments 10 to 12 and
axis small and hollow. Flesh orange-colored; tender, juicy,
aromatic; flavor rich and tart. Medium late in maturity.
Tree vigorous and productive with large, long-pointed
leaves. Less cold-resistant than
Orlando. Cross-pollination recommended for regular and heavy
production. Dancy, Clementine, and Kinnow mandarins appear to
be satisfactory pollinators. Orlando tangelo is
cross-incompatible.
Minneola is a
hybrid of Duncan grapefruit and Dancy tangerine produced in Florida by
the U.S. Department of Agriculture and named and released in
1931. Its attractive color, excellent flavor, and low seed
content have popularized it in Florida where it is currently of limited
commercial importance. There is increasing interest in its
culture in the low elevation desert regions of Arizona and California,
where total plantings were reported to be 594 acres in 1964.
Orlando (fig. 4-53)
Fruit medium-large, broadly oblate to subglobose; without neck;
seedy. Rind orange-colored; thin, slightly pebbled, and
fairly tightly adherent (not free-peeling). Segments numerous
(12-14); axis small and hollow. Flesh orange-colored;
tender, very juicy; flavor mildly sweet. Season of maturity
early.
Tree somewhat similar to
Minneola but with distinctively cupped leaves; somewhat more cold
resistant; less vigorous; cross pollination recommended for regular and
good production. Dancy, Clementine, and Kinnow mandarins and
Teumple tangor are said to be good pollinators. Minneola
tangelo is cross-incompatible.
Orlando
is of the same parentage as Minneola and Seminole—a hybrid of Duncan
grapefruit and Dancy tangerine. Originally it was named Lake,
but it was later renamed to avoid confusion. Its earliness
of maturity, good shipping quality, and pleasant flavor made it the
outstanding popular tangelo in Florida, where the annual production in
1965 exceeded a million boxes. In the low elevation regions
of Arizona and California, there is increasing interest in its
culture. Total plantings in 1964 consisted of 610 acres.
Pearl
This variety more closely resembles the grapefruits and pummelos.
Pina
This Variety more closely resembles the grapefruits and pummelos.
Sampson
This variety more closely resembles the grapefruits and pummelos.
San Jacinto
Fruit medium-sized, round or obovate; commonly slightly necked; color
orange-yellow; seedy. Rind relatively smooth, thin, fairly
free-peeling; axis hollow. Flesh color pale orange-yellow;
tender, very juicy; flavor sprightly and subacid. Maturity
season early.
Tree vigorous and productive; leaves small to medium, oval-shaped, and pointed.
This variety originated at the U.S. Date and Citrus Station, Indio,
California, as a seedling of an unnamed tangelo of grapefruit-tangerine
(presumably Dancy) parentage from a pollination made by Swingle in Florida in 1899. Introduced in 1931, San Jacinto has never attained commercial importance.
Seminole
Fruit medium-large, broadly oblate; color deep reddish-orange;
seedy. Rind somewhat pebbled, thin, and moderately adherent
though peelable; axis hollow; Flesh [sic] color rich orange;
tender, juicy; flavor sprightly and acid. Resembles Minneola
in appearance, but peels easier and matures later.
Tree vigorous and productive; leaves medium-small, rounded, and cupped (like Orlando and Sampson). Appears to be self-fruitful.
This variety is of the same parentage as Orlando and Minneola—Duncan
grapefruit crossed with Dancy tangerine—and has been planted to a
limited extent in Florida. Seminole has attracted little
interest in California, presumably because it is highly seedy and too
tart for most palates.
Sunrise (K-Early)
This variety more closely resembles the grapefruits and pummelos.
Sunshine
This variety more closely resembles the grapefruits and pummelos.
Suwanee
This midseason variety produces a large, seedy, deep-orange-colored
fruit. Suwanee is sister to Minneola and Seminole, having
originated from a cross of Duncan grapefruit and Dancy tangerine, and
has not achieved commercial importance.
Thornton
Fruit medium-large, oblate to broadly obovate; commonly somewhat
necked; light orange-colored; seedy. Rind pebbled and
somewhat rough, medium-thick, flexible, and only slightly adherent
(free-peeling); axis mainly hollow. Flesh color pale orange;
very soft and juicy; flavor mildly sweet. Midseason in
maturity. Puffs badly when overripe.
Tree hardy to cold, vigorous, and productive; leaves large and
long-pointed, resembling sweet orange.
Thornton originated as a grapefruit and tangerine (probably Dancy)
hybrid made by Swingle in Florida in 1899 and was named and released in
1904. It has failed to attain much commercial importance,
although it is grown somewhat as a specialty fruit in Texas and Florida.
Ugli (fig. 4-54)
Fruit large, broadly obovoid; usually with short, strongly furrowed
neck or collar; apex truncated and commonly strongly
depressed. Seeds few and monoembryonic. Rind
color dull yellowish-orange; medium-thick, leathery, moderately rough
and bumpy, somewhat ribbed, and loosely adherent. Segments
about 12 and axis large and open. Flesh orange-colored;
tender, very juicy; flavor rich and subacid. Maturity season
late.
Tree reported to be upright-spreading and mandarin-like in appearance.
According to Webber (1943), the rather unusual name for this natural
tangelo is said to have been given to this unattractive but delicious
fruit in the Canadian market which first received it. It was
referred to as the "Ugly" citrus fruit. Soon thereafter, the
name Ugli became the copyrighted trademark of G. G. R. Sharp, the
principal and for some time the only Jamaican exporter.
From the information he was able to obtain, Webber (1943) concluded
that Ugli originated as a chance seedling of unknown parentage near
Brown's Town, Jamaica. It came to notice in 1914 and was
propagated by F. G. Sharp at Trout Hall and first exported about 1934 by
his son, G. G. R. Sharp. It is obviously a hybrid with
characters that suggest mandarin and grapefruit parentage, hence Webber
provisionally classed it with the tangelos. Partly because of
the monoembryony exhibited by the seeds, it is the opinion of the
writer that pummelo is the parent in question rather than grapefruit.
While the fruit is unattractive, its shipping and eating quality have
given it a high reputation in Canadian and English markets and its
production is increasing in Jamaica.
Webber
Webber is a medium-sized, flat, thin-skinned orange-colored fruit of
good quality. The variety is of Duncan grapefruit and Dancy
tangerine parentage and was selected in Florida in 1909 and introduced
by the U.S. Department of Agriculture in 1932. It has never
achieved commercial importance.
Wekiwa
This variety more closely resembles the grapefruits and pummelos.
Yalaha
Fruit medium-sized, oblate; base slightly depressed and somewhat furrowed; orange-colored; seedy; Rind [sic]
pebbled and somewhat rough, medium-thick, slightly adherent; axis large
and hollow. Flesh color pale orange; tender, juicy; flavor
sprightly subacid. Late in maturity.
Tree vigorous and productive; leaves oval-shaped and pointed, resembling sweet orange.
Yalaha is a Duncan grapefruit-Dancy tangerine hybrid made by the U.S.
Department of Agriculture in Florida in 1911 and introduced in
1931. The variety has not achieved importance.
Other Mandarin-Like Fruits.—In
addition to the tangors and tangelos, however, there are certain other
citrus fruits of the Orient which have rather obvious resemblances to
the mandarin. Principal in horticultural importance among
these are the Calamondin, Iyo, and Rangpur.
Calamondin (Citrus madurensis Loureiro)
Fruit very small, oblate to spherical; apex flattened or
depressed. Rind color orange to orange-red; very thin,
smooth, and finely pitted, easily separable only at maturity; sweet and
edible. Segments about 9 and axis small and
semi-hollow. Flesh orange-colored; tender, juicy, and
acid. Seeds few, small, plump, polyembryonic, and with green
cotyledons. Fruit holds on tree remarkably well.
Tree of medium vigor, highly productive, upright and columnar, nearly
thornless; leaves small, broadly oval, and
mandarin-like. Strongly cold-resistant.
The mandarin-like Calamondin (fig. 4-55) is the Calamonding of the Philippines, the szukai-kat of southern China and Taiwan, the tôkinkan and shikikitsu of Japan, the djerook kastoori of Java, and the hazara of India.
There has been some doubt about the status of this
fruit. Swingle recognized it as a valid species in 1914, but
later failed to give it specific rating (see chap. 3, this work). Tanaka for some time retained its specific rank in what he designated as the Mitis subgroup. More recently, Tanaka (1954) has classed it as Citrus madurensis Loureiro.
Undoubtedly of Chinese origin, this fruit was early and widely
distributed throughout the Orient, including Indonesia and the
Philippines, where the earliest descriptions were
made. Although mandarin-like in most respects, it has
similarities with the kumquat and sometimes has been confused with that
fruit, particularly in India and Ceylon. Indeed, Swingle
(1943, p. 357) considered it to be a natural hybrid between a sour
mandarin and some kumquat.
The
Calamondin has little economic importance for the fruit but is widely
used as an ornamental in Florida and California. It is
especially attractive as a potted or tubbed plant in fruit and currently
is extensively grown and shipped to the population centers of the
United States for use as a winter house plant. It also makes
an excellent rootstock for the oval or Nagami kumquat, when grown for
similar purposes. Peters, an attractive, variegated-leaf form
is grown somewhat in California, primarily for landscape use.
Iyo (Iyomikan) [Citrus iyo Hort. ex Tan.]
Fruit medium-sized, subglobose to broadly obovoid; apical end shallowly
depressed. Rind thick, lightly pitted, tender, and easily
separable; deep orange-colored. Medium seed content (some
with pale green cotyledons). Central column broadly open and
segments about 10. Flesh orange-colored; tender, very juicy,
sweet; flavor rich and pleasant. Midseason in maturity.
Tree vigorous.
The Iyo is believed by Tanaka (1954) to be a natural tangor and was
found about 1883 by M. Nakamura in Obu-gun, Yamaguchi Prefecture,
Japan. First described as Anado mikan in 1892, it was
early introduced into Ehime (formerly Iyo) Prefecture, where it was
widely planted and came to be known as Iyo. While attractive
in appearance and of good flavor, it loses quality rapidly in storage
and on the tree. As a result, it has been little planted in
recent years. Currently, its culture is limited largely to
the vicinity of the city of Matsuyama.
Rangpur (Citrus limonia Osbeck)
Fruit small to medium in size, variable in form but mainly depressed
globose to round or broadly obovate; sometimes with furrowed collar or
low neck; often with short nipple partially or entirely surrounded by a
shallow furrow. Rind color yellowish to reddish-orange; thin,
and moderately loose, with surface minutely pitted and smooth to
slightly rough. Segments 8 to 10, loosely adherent; axis
large and hollow at maturity. Flesh orange-colored; tender,
juicy, and strongly acid. Seeds fairly numerous, small,
highly polyembryonic, and with light green cotyledons. Fruit
holds on tree for a long period.
Tree
usually vigorous and productive, medium-sized, spreading and drooping,
with slender twigs, comparatively few and small thorns; foliage
dull-green and mandarin-like, and new shoot growth lightly
purple-tinted. Flowers small and mandarin-like and buds and
petals deeply purple-tinged. Hardy to cold.
The description of the Rangpur given above is
generalized. Several clonal varieties of this mandarin-like
fruit have been selected and named and a comparatively wide variation
exists in fruit characters in regard to form, color, smoothness and
adherence of rind, and acidity and flavor.
Common names used for the fruit include Rangpur in India, Canton lemon in South China, hime lemon in Japan, cravo lemon in Brazil, Japanche citroen in Java, and Rangpur lime or mandarin-lime in the United States. Other Indian names include Sylhet lime, surkh nimboo, sharbati and
marmalade lime. The name lime employed in connection with
this fruit is misleading and should be avoided since the only
similarities between it and the true limes are that both have small
flowers and because they are both highly acid can be used as
substitutes.
Resemblances between the
Rangpur and mandarin are obvious and numerous, and for this reason it
is best included under the mandarin-like fruits. The rough
lemon and Rangpur also exhibit rather close similarities and important
differences.
Almost certainly of
Indian origin, the Rangpur early spread throughout the Orient and to the
East Indies. According to Webber (1943), it was introduced
into Florida in the late nineteenth century by Reasoner Brothers of
Oneco, who obtained seed from northwestern India. The Rangpur
is of horticultural importance primarily as a rootstock both in the
Orient and South America and as an ornamental. The three most
important forms of the Rangpur are discussed below.
Kusaie.—Generally
referred to as the Kusaie lime, presumably because of the yellow color
and high acidity of the fruit, Kusaie should be properly regarded as a
yellow-fruited form of the Rangpur and therefore called the Kusaie
Rangpur. The tree is indistinguishable from other Rangpurs
and the fruit differs significantly only in color.
Almost certainly this form or variety originated in India, for it markedly resembles the nemu-tenga
of Assam (Bhattachariya and Dutta, 1956) and is indistinguishable from a
promising rootstock used in trials in Punjab State and West Pakistan
called nasnaran, but which the writer identified as Kusaie
Rangpur. According to Webber (1943), this fruit was
introduced into Hawaii from Kusaie Island, of the Caroline group, by
Henry Swinton in 1885 and thence into the United States by Webber in
1914. It seems first to have been described by Wilder (1911,
p. 86).
Kusaie is said to have local
importance as an acid fruit in the Hawaiian
Islands. Elsewhere in the United States it is a collection
item or oddity.
Otaheite (fig. 4-56).—Usually
referred to as the Otaheite orange, this fruit should be properly
regarded as an acidless or sweet form of the Rangpur and therefore
should probably be called the Otaheite Rangpur. The tree is
similar to the common Rangpur but less vigorous and hence
dwarfed. It is almost thornless and the purple coloration on
the new shoot growth is more intense. Likewise, the fruit is
similar but somewhat smaller, more commonly necked, contains fewer
normal seeds (often none), and is insipidly sweet from lack of acid.
Since an acidless form of the Rangpur is known in India, this fruit
doubtless originated there. However, the first known
reference to it (Risso and Poiteau, 1818-22, p. 66) described it as Citrus otaitense, a small orange from Otaite (Tahiti) brought to Paris from England in 1813. How
or when it reached the United States is not known, but it was listed as
a potted ornamental in the 1882 nursery catalog of R. J. Trumble of San
Francisco, California (Butterfield, 1963). Easily propagated
from cuttings, as are all the Rangpur, it is extensively grown in the
United States as a potted ornamental, primarily as a winter house
plant. Several unnamed clones are recognized.
Rangpur (fig. 4-57).—The
clone or clones grown in the United States correspond with the general
description given above. It seems probable that one principal
clone is involved, since this fruit is highly polyembryonic and
reproduces remarkably true from seed. As grown elsewhere,
apparently there are several rather similar clones. This
appears to be the case in the Orient (Hodgson, Singh and Singh, 1963)
and is suggested by the observation of minor differences in a
collection of a dozen or more accessions from widely separated sources
assembled in California. The differences seem to be concerned
principally with the form of the fruit and nature of the rind surface.
In the United States (particularly in California), the Rangpur is
widely used as a hardy, dooryard fruit and ornamental and as a potted or
tubbed plant. It is especially well adapted for such uses
since it propagates readily from cuttings and is easily dwarfed when the
roots are confined. Outside the United States, its use seems
to be principally as a rootstock. Primarily because of its
tolerance to the tristeza virus and resistance to soil-borne diseases,
it is a rootstock widely employed, especially in Brazil where it is
known as the cravo lemon. When employed for such use, however, the scion materials must be free from exocortis virus, for the Rangpur as a rootstock is severely affected by that disease.
PUMMELOS AND GRAPEFRUITS
The pummelos, or shaddocks, and the grapefruits exhibit so many
resemblances in both tree and external characters that close botanical
relationship is obvious. Indeed, most systematists have
either placed them in the same species or classed the grapefruit as a
subspecies or botanical variety. The differences are more
basic and numerous than appear at first glance, however, and separation
into different species seems clearly justified. Nevertheless,
it cannot be denied that there are pummelos which so closely resemble
grapefruits that it is difficult to separate them with accuracy on any
basis other than the presence or absence of polyembryony.
The principal differences between the two groups are set forth in the
list of comparisons on page 534 adapted from Webber (1943).17
The pummelos as a group exhibit a very much greater range of variation
in characters than do the grapefruits. Some of them are
comparatively small trees, whereas others are among the largest of
citrus trees. Some exhibit a marked degree of pubescence on
the young growth, whereas others are scarcely, if at all,
Pummelo Characteristics Young twigs pubescent Leaves puberulent along midribs beneath Petioles usually very broadly winged Wings commonly overlapping blade Fruit size usually large to very large Fruits mainly round, obovate, or pyriform Rind usually thick to very thick Segments usually open at suture Axis semi-hollow or hollow Flesh commonly firm, sometimes crisp Flavor highly variable Carpellary membranes readily separable Seeds monoembryonic Fruits mainly borne singly | Grapefruit Characteristics Twigs glabrous Leaves glabrous Petioles broadly winged Wings rarely overlapping blade Fruit size medium to large Fruits mainly oblate, round, or obovate Rind thin to medium-thick Segments closed at suture Axis solid or semi-hollow Flesh tender and melting Flavor distinctive Carpellary membranes difficulty separable Seeds polyembryonic Fruits commonly borne in clusters |
Pummelo (Citrus maxima [Burm.] Merrill, C. grandis [L.] Osbeck or C. decumana L.)
It seems reasonably certain that the pummelo is indigenous to the
Malayan and East Indian archipelagos, whence it early spread to South
China and India and thence followed the same path as most of the other
citrus fruits to Europe and America. According to Tolkowsky
(1938), it was mentioned in Palestine in 1187 A.D. and in Spain about
the same time. Ferrari (1646) described and illustrated
several kinds in Italy. According to Webber (1943), it was
mentioned and described in Jamaica in 1696 under the name shaddock and
in 1707 an account of its introduction reported that seed of this fruit
had been brought to Barbados by a Captain Shaddock, in command of an
East Indian ship (see chap. 1, footnote 6). The
name, shaddock, has persisted ever since in the West Indies and the
United States. Pummelo is the preferred name, however, and
appears to have been derived from pompelmoes or pomplemoose, names given to it by the Dutch in the East Indies (Indonesia). In French it is the pamplemousse, in Italian the pompelmo, in Spanish the pampelmus, and in Japanese the buntan or zabon. The large size of the fruit is reflected in the species designations most commonly employed (maxima, grandis).
While most of the pummelos are inferior or worthless as fresh fruits,
there are superior kinds and varieties that are highly prized in the
Orient and grown commercially. The principal centers of such
production occur in southern China, Thailand (Siam), Vietnam
(Indo-China). [sic] Malaysia (Malaya), Indonesia, Taiwan
(Formosa), and Japan. The distribution of superior varieties
and the environmental conditions under which good eating quality is
attained appear to be restricted however, and elsewhere in the Orient
the fruit is used primarily for culinary and medicinal
purposes. In other parts of the citricultural world, the
pummelo has remained a collection item or novelty of interest
principally for breeding purposes because of its giant-sized fruits.
As previously noted, the pummelos comprise a highly variable
group. Some of them approach or equal the grapefruits in
vigor and size of the tree, but many of the commercial varieties are
much less vigorous and smaller, although apparently equally resistant to
neglect. In the limited area where comparisons have been
possible, pummelos have shown considerably less cold tolerance than the
grapefruits. While in heat tolerance they are comparable, the
pummelos exhibit a much wider range in heat requirement, some varieties
maturing earlier than any of the grapefruits and others attaining
acceptable quality only in regions of very high total heat.
The pummelos of highest repute in the Orient appear to be grown in
reclaimed coastal marsh areas subject to the flow of brackish tidal
waters which are high in salt content. This has given rise to
the belief that the presence of salt is related to, if not responsible
for, the distinctive quality of the fruit. Groff (1927) has
reported obtaining confirmatory evidence of this belief from tests of
salt application to the soil about trees. Whatever the facts
may be, it is true that production of good quality pummelos is highly
restricted in the Orient and that the best varieties have apparently
failed to develop equal quality in the United States or
Mediterranean basin. Only a few varieties have produced
fruits of reasonably good edibility in the United States, primarily in
Florida and the hottest interior areas of California and
Arizona. None of these fruits has proven as acceptable to
most palates as a good grapefruit.
Another distinctive feature of pummelo culture is the fact that
commercial propagation in most parts of the Orient is by means of
air-layerage (marcottage) rather than graftage.
Because of firmer flesh texture and lower juice content, many of the
pummelos, particularly most of the highly reputed varieties, do not lend
themselves to serving in the manner employed for the
grapefruit—spooning the flesh from the cut fruit or
juicing. After peeling the fruit, the segments are separated
and the carpellary membranes—commonly already burst at the suture—are
easily pulled away from the mass of pulp-vesicles (juice
sacs). Unlike the grapefruit, this can be accomplished
without rupturing the walls and the resultant escape of juice and
soiling of the hands. For table use, the pulp-vesicles are
shelled out into dishes and served with or without
sugar. None of the major varieties exhibit the trace of
bitterness characteristic of grapefruits, although there are bitter
pummelos.
Many if not most of the
commercially important varieties of Thailand, South China, and Taiwan
belong to a highly distinctive group, obviously of common ancestry and
presumably of Siamese origin. The trees are small to
medium-small, round-topped, and drooping in contrast with the medium to
large, broad-spreading trees of most pummelos. The branches
are less thorny, the twigs thicker and more densely pubescent, and the
leaves more round-pointed. The flowers are larger and more
woody in texture. The surface of the young fruits exhibits
pubescence which is often retained to maturity. The rind of
the mature fruits is less spongy and the flesh firm and crisp with tough
carpellary membranes and juice sac walls. The flesh is hence
much less juicy than most other pummelos. Varieties in this
group include Kao Pan and Kao Phuang of Thailand and Mato of China, Taiwan, and Japan.
With respect to fruit characteristics, the pummelos fall into both of
the natural groups found in the grapefruits and some of those which
occur in the sweet oranges.
Most
pummelos fall in the common or ordinary group, the fruits of which are
highly variable in nearly all respects except pigmentation and acid
content. They are all non-pigmented, moderately to highly
acid, and typically seedy, although there are varieties that are
virtually seedless or nearly so in the absence of cross pollination
(Soost, 1964).
Similar to the common
pummelos in all respects except that they are virtually devoid of acid
are the acidless or non-acid pummelos, a group analogous to the sugar
oranges. Comparable analyses of acid content and sugar-acid
ratios for a clone of this group and several common pummelos have been
reported by Soost and Cameron (1961). Results were as
follows: for an acidless clone, 0.08 to 0.10 per cent acid content and
ratios of 126-151.3 to 1; for four common clones, 1.02 to 1.93 per cent
acid content and ratios of 5.6-11.4 to 1.
The pigmented pummelos are similar to the common pummelos except for
the pigmentation caused by the carotenoid lycopene, which ranges from
light pink to deep red. Some of them are highly attractive
and excellent in flavor.
That there is
a pummelo group somewhat comparable with the navel oranges is suggested
by Reinking's (1929) report of a so-called double pummelo in the
Molucca Islands. From his description, the structure of the
fruit is similar to that of the double-fruit navel orange.
As would be expected, the varieties of commercial importance consist of
clones of the common and pigmented groups, the fruits of which are
oblate, round, or broadly pyriform, with relatively thin rinds, and
sweet to mildly acid in flavor. The writer must of necessity
rely upon the literature, which is limited, in describing the
characteristics of some of the varieties.
Common Group Varieties.—The
major varieties of the common group of pummelos are described
below. Among the introductions received in California from
the U.S. Department of Agriculture during the 1930-35 period, however,
there are several varieties, the history of which has been lost, which
are equal or superior to any of the major varieties. Only
one, Kao Kuan (Ruan) Tia is mentioned by Groff
(1927) and hence known to be of Siamese origin. The
California introduction corresponds rather well with his description,
although the original materials consisted of seedlings. The
other varieties are Karn Lau Yao, Pin Shan Yao, Pong Yao, and Tau Yao, all
presumably of Chinese or Siamese origin. All are
medium-large to large productive trees with fruits that are broadly
obovoid to short-pyriform. The fruits have medium-thin to
medium rinds and are juicy and of good to excellent flavor.
Banpeiyu (fig. 4-58)
Fruit very large (one of the largest), subglobose to spheroid;
seedy. Light yellow. Rind thick; surface smooth
and tightly adherent. Segments numerous (15-18); axis large
and solid; carpellary membranes thin but tough. Flesh color
pale yellow; tender and juicy; flavor excellent, a pleasant blend of
sugar and acid. Medium-late in maturity but stores well for
several months longer.
Tree very
vigorous, spreading and large; leaves large and broadly winged; twigs,
new shoot growth, petioles, and lower surface of leaves pubescent.
Banpeiyu is almost certainly the variety known as Pai You (Yau) on
Taiwan. The variety is of unknown Malayan origin and was
introduced into Formosa (Taiwan) in 1920, named in 1925, and taken to
Japan soon thereafter. It develops high quality fruit only in
the hottest regions of southern Japan. Among pummelo
varieties, it currently ranks first in Japan and second on Taiwan.
Hirado (Hirado Buntan)
Fruit large, oblate, slightly depressed at both ends;
seedy. Color bright yellow when mature. Rind
medium thick; surface smooth and glossy; tightly
adherent. Segments numerous and carpellary membranes thin but
tough. Flesh light greenish-yellow; tender and moderately
juicy; flavor a pleasant blend of sugar and acid with trace of
bitterness. Medium-early in maturity but stores well.
Tree vigorous, medium-large; leaves large, thick, and broadly
winged. More cold-resistant than most pummelos.
This variety originated as a chance seedling in Nagasaki Prefecture of
Japan, was named and introduced about 1910, and is currently second in
importance there.
Kao Pan (Kao Panne)
Fruit medium-large, subglobose to spherical; apex slightly depressed;
seedy if open-pollinated, but otherwise not (Soost,
1964). Lemon-yellow (deeper than most) at
maturity. Rind medium-thick; faintly pebbled with prominent
oil glands; tightly adherent. Segments numerous (12-15);
carpellary membranes thick and tough; axis medium-small and
solid. Juice sacs large, fleshy, easily separable, and
moderately juicy. Flavor sweet and mildly
acid. Early in maturity.
Tree medium-small, round-topped and drooping, nearly thornless; leaves
medium-large and round-pointed; twigs and new shoots densely pubescent;
large, woody flowers.
According to
Groff (1927), Kao Pan is one of the most highly reputed varieties of
Thailand and almost certainly originated in the Nakorn Chaisri
district. Groff considers Nakorn to be a synonym. In California, however, Nakorn more closely resembles Kao Phuang;
both clones were received from the U.S. Department of Agriculture in
1930. The reason for this discrepancy doubtless resides in
the fact that the original introductions into the United States were
budded plants in the case of Kao Pan and Kao Phuang and seeds in the
case of Nakorn.
Kao Phuang
Fruit large, broadly pyriform with distinct neck; apex even or slightly
depressed; seedy if open-pollinated but otherwise not (Soost,
1964). Lemon-yellow at maturity. Rind
medium-thick; surface smooth, glossy; less tightly adherent than Kao
Pan. Segments numerous and easily separable; carpellary
membranes moderately thick and tough; axis small and
solid. Vesicles large, easily separable, and firm but
juicy. Flavor good (more acid than Kao
Pan). Medium-late in maturity and holds well on tree with
retention of quality.
Tree similar to Kao Pan, but somewhat more vigorous and upright.
Groff (1927) reports that Kao Phuang is recognized as one of the two
best varieties in Thailand, some persons preferring it to the famous Kao
Pan. In California, its flavor is clearly
superior. In the collections at the University of California
Citrus Research Center, Riverside, one of several clones received under
the name Siamese is indistinguishable from Kao Phuang, and is probably
identical.
Mato (Mato Buntan) (fig. 4-59)
Fruit medium-large, broadly obovoid to pyriform;
seedy. Light-yellow at maturity. Rind
medium-thick; surface coarsely pitted, pebbled from protuberant oil
glands; tightly adherent. Segments numerous (12-16) and
carpellary membranes thin but tough. Flesh color light
greenish-yellow; crisp, somewhat tough, lacking in juice; flavor sweet
(mildly acid), sometimes with trace of bitterness. Early in
maturity.
Tree dwarfed and small,
round-topped and drooping; twigs and shoot growth short, thick, and
densely pubescent; leaves large, thick, and pubescent on the lower
surface.
This variety is said to have
been taken from South China to Taiwan about 1700 and thence—but much
later—to Japan. Mato is currently first in importance among
pummelo varieties in Formosa and ranks third in Japan. From
the description, it is obviously of the small-tree Siamese type and has
numerous resemblances to such varieties as Kao Pan and Kao Phuang.
Mato is the seed parent of the comparatively new and promising Tanikawa buntan, the pollen parent of which is presumed to be the Japanese Sanbôkan. That
it is of hybrid origin is strongly suggested by the facts that (1) the
tree is more vigorous, conspicuously upright in growth habit and
appreciably more cold resistant, and (2) the fruit is smaller, with much
thinner rind and deeper color, and the flesh is tender, juicy, and of
excellent flavor. Moreover, the number of segments is about a
third fewer and the season of maturity late.
Tanikawa originated at the Horticultural Research Station, Okitsu,
Japan, from pollinations made during the period of 1913 to 1925 and was
named for the originator, T. Tanikawa. It has been planted to
a limited extent in Kagoshima Prefecture, but it is not yet grown
extensively.
Moanalua
See under Tahitian.
Nakorn
See under Kao Pan.
Siamese
See under Kao Phuang.
Tahitian (Moanalua)
Mention should be made of the so-called Tahitian grapefruit because of
its distinctive characteristics and high quality. This
agreeably-flavored fruit is in reality a thin-rinded, highly juicy
pummelo. The seeds are monoembryonic and otherwise
typical of the pummelo and the shoot growth is much more pubescent than
any of the grapefruits. The faintly amber flesh color
suggests the possibility that it may be lightly pigmented under
conditions more favorable for color development.
The origin of Tahitian is obscure but it is believed to have developed
in Tahiti from seed from Borneo whence it was taken to
Hawaii. The variety is of local and limited importance only,
but is highly reputed for its excellent quality.
Tanikawa
See under Mato.
Pigmented Varieties.—Major
pigmented varieties of the pummelo are described
below. Numerous other pink or red-fleshed clones are known to
exist in the Orient but information is not available concerning their
importance or characteristics.
Chandler
Fruit medium in size, oblate to globose; seedy. Rind
medium-thick, smooth, and sometimes faintly pubescent. Flesh
firm but tender, moderately juicy; flavor intermediate between acidless
and moderately acid parents. Early in maturity and stores
well.
Chandler is a synthetic variety,
recently described and released by the University of California Citrus
Research Center, Riverside (Cameron and Soost, 1961). It is
pink-fleshed like the pollen parent, Siamese Pink, but otherwise
intermediate in characteristics between it and the seed parent, Siamese
Sweet.
Egami
See under Ogami below.
Ogami
One of the better varieties in Florida is Ogami, which corresponds
sufficiently well with the description of the Japanese Egami buntan
to warrant the conclusion that they are probably the
same. The fruit is large and broadly oblate, with a
moderately thick, smooth rind and numerous seeds. The flesh
is moderately firm, juicy, and of good flavor. In Florida,
rind pigmentation is very faint or lacking, but the flesh is deep pink
(almost red) extending into the albedo.
Pandan Bener
Ochse (1931) describes the Pandan Bener as one of the two best
varieties in the Batavia district of Java. The fruit is
oblate to globose in form, red-fleshed, pleasantly flavored, and sweet
with a slight amount of acid. The tree is large and vigorous,
but less productive than the Pandan Wangi (see below).
Pandan Wangi
This variety is ranked with Pandan Bener as one of the two outstanding
varieties of the Batavia district of Java (Ochse, 1931). The
red-fleshed fruit is oblate to globose in form, has a slight acid
content, and is pleasantly sweet flavored. The tree is
described as vigorous, large, and productive.
Siamese Pink (Siam)
Fruit large, broadly obovate to short pyriform with shallow depression
at apex; nearly seedless. Light yellow at maturity in
California, but probably pink-tinted in semitropical
climates. Rind medium-thick; surface smooth; tightly
adherent. Segments numerous and carpellary membranes
moderately tough, but commonly split open at axis at
maturity. Flesh coarse-grained, pink-tinged; very juicy;
flavor grapefruit-like (subacid with trace of
bitterness). Late in maturity.
Tree vigorous, very large, and spreading; leaves typical—broad-pointed;
twigs and shoot growth faintly pubescent.
This clone, which was received by the Citrus Experiment Station,
Riverside, from the U.S. Department of Agriculture in 1929 under the
name Siamese Pink (CES 2246) corresponds ell with the variety Siam,
named and described by Wester (1917). According to Wester, it
was introduced into the Philippine Islands in 1913. In
California, when fully ripe it is clearly one of the best in flavor,
although sometimes it has a trace of bitterness.
Thong Dee
Fruit medium-large, very broadly obovoid to oblate; apex slightly
depressed; seedy. Light yellow at maturity. Rind
medium-thin, smooth, and tightly adherent. Under favorable
conditions both albedo and flesh are pink-tinged, the latter in
streaks. Carpellary membranes thin but tough and readily
separable from pulp. Vesicles large; juice plentiful; flavor
good. Midseason in maturity.
Tree vigorous and large.
The description of this Siamese variety was adapted from Groff (1927)
and does not correspond with the clone received in California in 1930
from the U.S. Department of Agriculture. Groff states,
however, that the original materials sent to the United States consisted
of seeds and seedlings. The clone in the California
collections produces non-pigmented fruits of indifferent
quality. That grown in Florida seems to be different since it
is reported to correspond with Groff's description.
Sweet or Non-Acid Varieties.—At least two clones of the non-acid (hence sweet) pummelo group are known and there are doubtless others.
The clone known in the United States (fig. 4-60)
was introduced by the U.S. Department of Agriculture in 1930 and was
received by the Citrus Research Center, Riverside, California, under the
name Siamese Sweet (CES 2240).
The tree is typical of the Siamese group in all respects—dwarf and
drooping, with round-pointed leaves and densely pubescent twigs and new
shoot growth. The fruits are oblate to broadly obovoid, with
large, crisp, easily separable juice sacs lacking in juice, and
insipidly sweet with a trace of bitterness. Siamese Sweet is
of horticultural interest primarily as a curiosity and also because it
is the seed parent of the recently released Chandler variety (Cameron
and Soost, 1961).
The other non-acid clone is the Ama or Mikado buntan of Japan, which Y. Tanaka has described as the botanical variety dulcis
(Tanaka, 1948). From his description and illustration, the
tree is indistinguishable from Siamese Sweet but the fruit is subglobose
to spherical.
Grapefruit (Citrus paradisi Macfadyen)
The origin and significance of the name of this important fruit are
obscure. According to Webber (1943), who made a comprehensive
search of the literature, the earliest recognizable mention of
grapefruit occurred in Barbados (West Indies) in 1750 under the name
"forbidden fruit," from which the species designation, paradisi,
was assigned in 1830. A few years later it was referred to in
Jamaica as the "forbidden fruit or smaller shaddock." The first known
use of the term grapefruit occurred in 1814, also in Jamaica, in which
it was referred to as a special and smaller kind of shaddock whose
flavor somewhat resembled that of the grape. It seems more
likely, however, that the name was derived from the fact that the fruits
commonly occur in small clusters rather than singly, as with most
shaddocks (pummelos). Early in the present century, the name
pomelo was proposed and for a time was used by American
horticulturists. It was not accepted by the industry,
however, and has now virtually disappeared. The Spanish name
is toronja.
Almost certainly,
the grapefruit originated in the West Indies, for it is not described in
the old literature and was not known in Europe or the Orient until
after its discovery in the Western Hemisphere. That it was
derived from the pummelo is certain, but whether by somatic mutation or
natural hybridization is not known. It is the opinion of the
writer, based on observations of numerous natural hybrids of the pummelo
in northeastern India, Sikkim, and eastern Nepal, that the grapefruit
originated as a natural hybrid.
The
attractive qualities of the grapefruit were early recognized and even
prior to the time it was first referred to by that name in the
literature it was said to be common in Jamaica and was probably known
throughout the West Indies. It remained for Florida, however,
to introduce this excellent fruit to the American consumer and to
develop a commercial industry. This fact explains why, with
the sole exception of Redblush (Ruby), all the grapefruit varieties of
commercial importance have originated in Florida and apparently trace
back to the original introduction.
According to Ziegler and Wolfe (1961), the introduction in Florida was
made by Count Odette Phillippe, a Frenchman, who settled near Safety
Harbor on Tampa Bay in 1823 and brought with him seeds or seedlings of
the grapefruit and other citrus fruits from the Bahama
Islands. Webber (1943) states that the introduction occurred
about 1809 and quotes a pioneer grower of that district who in 1892
reported that the citrus materials in question were said to have come
from Cuba. Whatever the facts may be, it was from this
introduction that the commercial grapefruit industry of the world
developed. The Florida
commercial industry, however, had its beginning about 1885, by which
time trial shipments made to Philadelphia and New York bad met with a
favorable reception and demand for nursery trees was
developing. Commercial production elsewhere was not
undertaken until some decades later in California, Arizona, and Texas
and more recently in other parts of the citricultural world.
Because of the phenomenal development of the industry in Florida and
Texas, within a half-century from the beginning of its commercial
culture the grapefruit attained the status of a major citrus
fruit. With a production exceeding 52 million boxes in 1965,
the grapefruit closely approaches the mandarins in importance and
exceeds the lemon, comprising about 10 per cent of the world production
of citrus fruits. The United States is much the largest
producer, accounting for about 80 per cent of the world crop (mainly in
Florida), followed by Israel, the West Indies (including Jamaica and
Cuba), Argentina, and South Africa. Grapefruit is also grown
to a limited extent in Spain, Morocco, Australia, Algeria, and Cyprus.
The grapefruit tree is vigorous and under favorable conditions is one
of the largest citrus trees, requiring more space than any
other. Its resistance to heat is outstanding and in cold
tolerance it closely approaches the sweet orange. Like the
bitter orange, it withstands neglect to a considerable
degree. As a consequence, the grapefruit exhibits a wide
range of climatic adaptation. Its very high heat requirement
for the production of fruit of good quality, however, restricts its
commercial culture to hot climates. This requirement coupled
with its marked heat resistance render the grapefruit almost equally
well adapted to hot desert and humid semitropical or tropical climates,
in which respect it is approached only by some of the mandarins.
Effects of the climatic environment on the characteristics of the fruit
are striking and important. Under desert conditions the
color is brighter and deeper and the flavor more sprightly and
pronounced than in humid climates, accompanied by somewhat smaller size,
less oblate form, and lower juice content. The differences
are sufficiently great to constitute a natural trademark and to provide
the markets with fruits for a wide variety of tastes and preferences.
Because of its refreshing flavor and the mild bitterness contributed by
the glucoside naringin, the fresh grapefruit is unexcelled as a
breakfast fruit served either in halves or as juice. It is
also widely used as a salad fruit and to some extent for
dessert. Because of overproduction which occurred in the
1920's, it early received attention from the processors with the result
that the first commercially successful canned citrus products were
single-strength grapefruit juice and fruit segments
(hearts). Improved over the years, these products have
achieved consumer acceptance and industry importance. During
the 1961-62 season some 9 million boxes (90-1b) were used for
single-strength canned grapefruit juice and 3 million for canned
grapefruit sections. While important, the impact of the
recent frozen concentrate juice process on the grapefruit industry has
been much less spectacular than occurred with the orange
industry. Thus, the utilization of grapefruit for this
excellent product in 1961-62 amounted to only 2.7 million boxes and up
to 1966 never exceeded 4.5 million boxes. During the decade
ending in 1966, on the average slightly less than half of Florida
production was used for processing.
Essential oil and pectin are the principal byproducts obtained from the
rind. Grapefruit seed oil is an interesting byproduct of
minor importance.
The grapefruits fall
into two natural groups—the common and pigmented grapefruits—which are
similar to two of the four groups found in the sweet
oranges. On the basis of season of maturity, they may be
early, midseason, or late. In general, the seedy varieties
are early or midseason and the seedless varieties are late in
maturity. Where legally permissible, however, such as in
Florida and certain foreign countries, these differences virtually can
be eliminated by the use of arsenical sprays, which act to reduce normal
development of acidity.
Common Grapefruit.—The
common or ordinary grapefruit is increasingly referred to in the trade
as the white grapefruit to distinguish it from the pigmented
varieties. Typically, the trees are vigorous, large, and very
productive and the fruit is seedy and rich in flavor. From
the early seedling plantings in Florida, all of which trace back to the
original introduction, numerous selections were made many years ago and
named as varieties. The most important of these is Duncan,
which was a seedling from a tree in the original
planting. Many if not most of these early named varieties
have proved to be indistinguishable and doubtless represent the same
parental clone. In the markets of the United States, the
fruit from seedling trees and some of these varieties, of which there
remains considerable acreage, is usually sold under the name Florida Common.
Connoisseurs generally agree that the flavor of the seedy fruits is
richer and more pronounced than that of the so-called seedless
varieties. Since they also mature earlier and exhibit better
section stability in canning, processors prefer the seedy fruits and in
recent years extensive plantings of such varieties have been made.
The first commercially seedless grapefruit (with few or no seeds),
later named Marsh, became available in 1889 and because of that highly
desirable characteristic within a few decades attained dominance in
Florida and became the leading grapefruit variety of the world, a status
it has retained ever since. More recently, at least two
other seedless varieties of the common grapefruit type have been found,
namely Davis in Florida and Cecily in South Africa, neither of which has
attained much commercial importance.
Among the early named varieties are several such as Royal and Triumph,
the fruits of which differ from the usual seedy grapefruit, as typified
by Duncan, in that they are smaller, less oblate in form, sometimes with
persistent style, somewhat deeper in color, less pronounced in flavor
and bitterness, and usually earlier in maturity. The
possibility has been suggested that they may be natural
grapefruit-orange hybrids (orangelos). None has attained
commercial importance.
Major Common Grapefruit Varieties.—Of
common grapefruit varieties, only Marsh and Duncan are currently being
planted on an important commercial scale, the former in all parts of the
world where grapefruit is grown and the latter principally in Florida
and primarily for processing. The most important varieties
are described below.
Bowen
See under Duncan below.
Duncan (fig. 4-61)
Fruit large, oblate to globose or broadly obovate; basal furrows short
and radiating; areolar ring faint; seedy. Color pale to light
yellow. Rind medium-thick and surface smooth and
even. Flesh color buff to chamois-colored; tender, very
juicy; flavor pronounced and excellent. Medium-early in
maturity.
Tree vigorous, large, very productive, and reputed to be probably the most cold-resistant.
This variety represents the oldest grapefruit clone grown in Florida,
though it was not named and introduced until about 1892. As
near as can be determined, the parent seedling tree was planted around
1830 near Safety Harbor, on the Pinellas Peninsula,
Florida. The seed came from a tree in the original planting
made by Count Odette Phillippe, who is credited with having brought the
grapefruit to Florida from the West Indies. It was named for
the introducer, A. L. Duncan of nearby Dunedin.
Since the grapefruits are highly polyembryonic and all varieties and
seedlings in Florida trace back to the planting which contained the seed
parent of Duncan, the probability is good that many, if not most, of
them represent the same clone. Certainly many of the early
named varieties are indistinguishable from Duncan and have been marketed
under that name. It has recently been established (Cooper,
Reece and Furr, 1962) that the Bowen variety used in some of the early
citrus breeding work in Florida was in reality Duncan.
In flavor, Duncan has remained the standard of grapefruit excellence in
Florida although seedless varieties have largely displaced it in the
fresh fruit markets. With the advent of processing, however,
its flavor and better suitability for canning have renewed interest in
this excellent variety and it constituted about 7 per cent of the
grapefruit planted between 1956 and 1966.
Marsh (Marsh Seedless, White Marsh) (fig. 4-62)
Fruit medium in size, oblate to spherical; areole ring indistinct or
lacking; seeds few or none. Color pale to light yellow at
maturity. Rind medium-thin, tough; surface very smooth and
even. Flesh buff-colored; tender, very juicy; flavor good
though not so pronounced as in some seedy varieties. Holds
unusually well on the tree and ships and stores well. The
latest-maturing of all commercial varieties.
Tree vigorous, spreading, large, and productive. Because of
high heat requirements, commercially restricted to very hot climates.
According to Webber (1943), Marsh apparently originated as a chance
seedling planted about 1860 on a farm near Lakeland,
Florida. Its commercial value as a seedless variety was not
recognized until 1886, however, when it was brought to the attention of
E. H. Tison of the Lakeland Nursery Company, who immediately arranged
for its propagation and introduced it soon thereafter as a choice
seedless variety. A few years later it was given its present
name by C. M. Marsh, who had acquired the Lakeland
Nursery. According to Mr. Tison, the owner of the farm on
which the parent tree occurred insisted that it developed as a root
sprout from an old seedling tree which produced seedy
fruit. While this is possible, it seems highly improbable.
Primarily because of its comparative seedlessness, within a few years
after its introduction Marsh became the variety most planted in Florida
and virtually the only variety planted elsewhere. It is still
by far the leading variety and is worldwide in its distribution.
Marsh is of unusual horticultural interest not only because it was the
first seedless grapefruit variety discovered but also because the
pigmented varieties currently of greatest commercial importance trace
back to it. Thus, Thompson (Pink Marsh) originated as a limb
sport of Marsh and Redblush (Ruby) or Red Marsh occurred as a bud
mutation of Thompson. On the other hand, Marsh has also given
rise to inferior bud variations, frequently characterized by a
reversion to seediness.
Other seedless
varieties of more recent origin, virtually indistinguishable from
Marsh, include Cecily of South Africa and Davis.
Nucellar clonal budlines are currently of importance in Texas, Arizona
and California, principal among which are Frost, CES (Citrus Experiment
Station, Riverside, California), and USDA (U.S. Date and Citrus Station,
Indio, California). Reed, a seedling that originated in the
dooryard of J. F. Reed of Taft, California, is one of the most recent
selections to receive attention.
Triumph
Fruit medium-small, oblate, globose, or ellipsoid; somewhat flattened
at both ends; very seedy. Color pale to light
yellow. Rind medium-thick with ver smooth
surface. Fish tender and very juicy; flavor lacking in
bitterness and exceptionally good. Early to midseason.
Tree less vigorous than most grapefruits but productive.
This was the first named grapefruit variety, having been offered to the
public in 1884. The parent tree, presumably a seedling, was
situated in the grounds about the Orange Grove Hotel in Tampa, Florida.
Being the first named variety, it was early and widely distributed
though it did not achieve much commercial importance and has been little
planted for many years.
Its lack of
bitterness and rich flavor are suggestive of the orange and some have
thought that it might be a natural orangelo (orange-grapefruit
hybrid). In lack of bitterness it rather closely resembles
Imperial of California origin and is somewhat like Mott (Aurantium),
Leonardy, and Royal, all of Florida origin, though the latter is even
more orange-like. Indeed, these varieties appear to
constitute a natural group of grapefruits in which the distinctive
bitterness is lacking or they may be of hybrid origin. With
the exception of Triumph, currently employed primarily for home
planting, none of them has attained commercial importance.
The Jackson variety of South Africa is said to be a seedless budsport of Triumph.
Walters
Walters is a midseason variety that produces medium-large, seedy fruits
with relatively thin rinds and excellent and pronounced flavor.
It originated as a seedling near Belleview, Marion County, Florida, and
was introduced in 1887 by a Mr. Walters through a local nursery.
Walters was never planted extensively but has special horticultural
interest because it has given rise through bud mutation to two other
varieties—Foster, the first pink-fleshed variety of record, and Cecily, a
seedless South African variety similar to Marsh.
Wheeny
See under pummelo hybrids.
White Marsh
See under Marsh.
Pigmented Grapefruit Varieties.—While
pigmented pummelos have been known for centuries in the Orient and were
early brought to the West Indies, it was not until 1907 that the
first-recognized, pink-fleshed grapefruit, the seedy Foster variety, was
found. Shortly thereafter (1913), a seedless pink-fleshed
limb sport of Marsh was discovered which in 1924 was propagated as the
Thompson variety. Only five years later a seedless
red-fleshed fruit, Redblush (Ruby), was found as a limb sport of
Thompson in the Lower Rio Grande Valley of Texas.
Though of attractive appearance and excellent quality, because of its
seediness the Foster variety never achieved commercial
importance. Thompson became available just as the Texas
industry began its phenomenal development and was therefore planted
extensively. The favorable reception accorded it in the
markets caused it to be planted somewhat extensively in
Florida. When Redblush became available in the markets,
however, the deeper color of the flesh and the attractive pink blush on
the rind, which is lacking in Thompson, made it an immediate
favorite. As a consequence, the Thompson variety rapidly lost
favor and for years past Redblush has been the only pigmented variety
widely planted. Redblush is now grown extensively in Florida and Texas and to a limited but increasing extent in Arizona and California.
Until processing methods are perfected to retain the natural color of
the lycopene pigments, the utilization of the pigmented varieties will
largely be restricted to fresh fruit outlets. The conditions
responsible for the development of the pink or red coloration are not
well understood, but it is clear that they differ somewhat from those
involved in coloration of the blood oranges. That heat is a
requisite is evident from the fact that coloration does not occur in
regions of low total heat and is most intense in the hottest
regions. Also, no chilling requirement seems to be involved,
for excellent coloration occurs in both Florida, Texas, and tropical
regions. Rootstock influence seems also to play an important
role in coloration.18
Although different pigments are involved and the climatic requisites
for their development differ somewhat, the pink-fleshed grapefruits may
be considered to correspond with the light blood oranges and the
red-fleshed varieties with the deep blood orange group.
Of particular interest in respect to the mode of origin of pigmented
grapefruit varieties is a recent report (Cameron, Soost, and Olson,
1964) showing that nucellar seedling clones of the Thompson and Foster
varieties do not exhibit the same degree of pigmentation as do the
parent varieties. Pigmentation is lost in the nucellar
Thompson and increased in the nucellar Foster. The degree of
pigmentation remains unchanged, however, in the Redblush (Ruby) and
Shambar varieties. Convincing evidence is presented that
chimeric constitution of the parent clones is the cause of this
interesting behavior. It is postulated that both clones are
periclinical chimeras that carry a color factor in germ layers 1 and
11. A somewhat similar situation is reported to exist in the
true sweet lemon (Chapot, 1963d).
The most important pigmented grapefruit varieties are described below:
Foster (Foster Pink)
Fruit medium-large, oblate to spherical; basal furrows short,
radiating; areolar ring indistinct; very seedy. Primary color
pale to light yellow, but under favorable conditions rind blushed with
pink, extending into the albedo. Rind medium-thick and
surface smooth. Primary flesh color chamois, but under
favorable conditions pink; flesh texture tender and juicy; flavor
good. Medium-early in maturity.
Tree vigorous, large, and productive.
This variety originated as a limb sport in a tree of the Walters
variety in an orchard near Ellenton, Florida, and was discovered in 1907
by R. B. Foster of nearby Manatee. It was introduced in 1914
by the Royal Palms Nurseries, Oneco.
Foster is of horticultural interest primarily because it is the first
pigmented grapefruit variety of record in Florida. As such,
it attracted considerable attention and was planted to a limited extent
both in Florida and Texas. With the advent of the seedless
pink-fleshed Thompson variety only ten years later, however, interest in
Foster declined abruptly and it has not been planted for many years.
Another reason for horticultural interest in this variety is the fact
that in Texas it gave rise by bud mutation to the seedless pink-fleshed
variety, Foster Seedless, which closely resembles Thompson but exhibits
somewhat better flesh coloration. Nucellar seedlings of
Foster also possess more intense pigmentation than the parent clone.
Pink Marsh
See under Thompson.
Redblush (Ruby, Red Marsh, Red Seedless) (fig. 4-63)
Fruit similar to Thompson
in all respects except for much deeper pigmentation in the flesh (but
not in the juice), crimson blush on the rind, especially at points of
contact between fruit; albedo pigmented. Holds on tree as
well as Marsh or Thompson but with some fading of flesh
color. Similar to Thompson in season of maturity.
Tree indistinguishable from Thompson or Marsh.
While the name Ruby has a slight time priority, Redblush seems
preferable to avoid confusion with the much older Ruby orange
variety. Moreover, Redblush is more descriptive of this
variety and is the name most used in the region of its origin.
Ruby (Henninger Ruby Red) originated as a limb sport of Thompson that
was found in 1929 by A. E. Henninger of McAllen, Texas, and patented by
him in 1934. So far as is known this was the first citrus
variety to receive a patent (U.S. Plant Patent No. 53).
Redblush (Webb Redblush) is said to have originated as a limb sport,
also of Thompson, that was observed in 1931 by J. B. Webb of Donna,
Texas, propagated soon thereafter, and introduced in 1934.
Ruby and Redblush are so similar as to be indistinguishable and for all
practical purposes they may be considered to be identical. A
number of similar bud mutations are known to have occurred subsequent
to the two now generally propagated as Redblush or
Ruby. Thus, Waibel (1953) lists seven bud mutations which
tests by the Texas Agricultural Experiment Station have shown do not
differ significantly in appearance, season, or yield. Ziegler
and Wolfe (1961) state that several mutations have occurred in Florida
that cannot be distinguished from Ruby.
Nucellar clonal budlines are currently of great interest and are being
planted commercially, in Texas, Arizona, and the Coachella Valley of
California. The oldest and most popular of these is CES
Redblush No. 3, which was produced at the University of California
Citrus Research Center, Riverside.
Because of the attractive appearance provided by the pigmentation of the
rind and its deeper flesh coloration, Redblush (Ruby) rapidly
superseded Thompson and some years ago became by far the leading
pigmented variety and one of the major grapefruit varieties.
Red Marsh
See Redblush above.
Red Seedless
See Redblush above.
Thompson (Pink Marsh)
Fruit medium in size,
oblate to spherical; areole indistinct or lacking; seeds few or
none. Pale to light yellow at maturity. Rind
medium-thin, tough, and surface very smooth. Primary flesh color chamois to dark buff, but under favorable conditions light pink (but not in juice); albedo not pigmented; flesh texture tender and juicy; flavor good, similar to Marsh. Holds on tree unusually well, but with considerable fading of color; ships and stores well. Midseason in maturity, (earlier than Marsh).
Tree vigorous, large, and productive.
This variety originated as a limb sport in a Marsh tree in an orchard
owned by W. B. Thompson at Oneco, Florida. While discovered
by S. A. Collins in 1913, it did not become available until 1924 when it
was named and introduced by the Royal Palms Nurseries, also of Oneco.
Because of its seedlessness, Thompson immediately attracted attention
and was extensively planted in Texas and to some extent in Florida,
quickly replacing the still new Foster variety. In turn, it
has long since been superseded by the more deeply pigmented Redblush
variety, which also is more attractive because of the rind coloration it
exhibits.
Thompson remains of
horticultural interest, however, because it was the first seedless
pigmented variety to be discovered and within a few years gave rise by
bud mutation to a number of more deeply pigmented
clones. Among these are Redblush, the variety that replaced
it and has become by far the most important pigmented grapefruit
variety, and the more recent Burgundy. In addition, nucellar seedlings of Thompson do not exhibit the pigmentation of the parent clone.
Several other pink-fleshed seedless limb sports of Marsh have been
reported. Shamel (1920) has described one which was found at
Corona, California, and more recently Waibel (1953) has mentioned two
which occurred in Texas. All markedly resemble Thompson.
Minor Grapefruit Varieties.—Both common and pigmented grapefruit varieties of minor importance are combined in the descriptions given below.
Burgundy (Burgundy Red)
This variety produces a seedless, red-fleshed, late-ripening fruit that
in Florida fails to develop external rind coloration. It is
said to be intermediate in size between Redblush (Ruby) and Thompson and
somewhat less juicy than either. The flesh color is
appreciably deeper than Redblush and the color is retained much later.
The parent tree was found about 1948 in an orchard of the Thompson
variety near Ft. Pierce, Florida, that belonged to Hudson J. McReynolds
of Orlando. Since it occurred as an entire tree, the
probability is that Burgundy originated as an undetected bud sport of
Thompson that was unwittingly propagated by the Glen St. Mary Nurseries,
who provided the trees for the McReynolds orchard. Burgundy
was introduced commercially in 1956 and has been planted to some
extent. According to F. E. Gardner of the U.S. Department of
Agriculture, Orlando, who provided the facts given here, this variety
received U.S. Plant Patent No. 1276 in 1954. Like the parent
variety, its nucellar seedlings are not true for pigmentation.
Cecily
This South African variety is so similar to Marsh that the two are
virtually indistinguishable. It was found near Uitenhage,
Cape Colony, in 1922, presumably as a limb sport, in a small planting of
trees of the Walters variety that had been imported from
Florida. It was named by the owner, Sir Percy Fitzpatrick, in
honor of his daughter Cecily.
In
South Africa, it is said to differ somewhat in growth habit from Marsh
and the fruit is less oblate and of finer texture. In
California, however, these differences have not been
noted. It is grown to some extent in the region of its origin
but is not replacing Marsh elsewhere.
CES Redblush
This nucellar seedling of Redblush (Ruby) was derived at the University
of California Citrus Research Center, Riverside, about 1945 and
re]eased about ten years later. That selection known as
Number Three (No. 3) has been most used.
Clason
Clason is a seedy, midseason, Arizonan variety that is
indistinguishable from most of the named seedy Florida
varieties. Of unknown origin and probably a seedling, it was
grown on a limited scale in the Salt River Valley for a decade or two
but has not been planted in recent years.
Davis
Davis is a seedless grapefruit variety in Florida so similar to Marsh
that they are indistinguishable to the writer. Traub and
Robinson (1937, p. 778) state that there are minor differences, however,
and report that Davis originated as a seedling, presumably of nucellar
origin, that came "from a cross between a seedling type of grapefruit
and a tangerine (in the attempt...to secure a tangelo)." Davis has not
achieved commercial importance.
Foster Seedless
This Texas variety is a seedless Foster with somewhat better rind
coloration. According to Waibel (1953), it was first noted in
1928 in the crop from a small planting of the Foster variety near
Mission, Texas, made with trees brought in from Florida. The
limb sport was located in 1931, but the parent tree was inadvertently
destroyed shortly thereafter. Fortunately, however, it had
been propagated and the clone was rediscovered by Joseph Hollerbach in
1932 in a young planting nearby. Because of the availability
of the more deeply-pigmented Redblush variety, however, Foster Seedless
has not attained commercial importance.
Frost Marsh
This variety is a nucellar seedling of Marsh that was derived by H. B.
Frost of the University of California Citrus Research Center, Riverside,
from seed planted in 1916. It was introduced commercially in
1952. Currently, it is the principal clonal selection of
Marsh under propagation in California and South Africa.
Imperial
This California variety produces a medium-small, very seedy fruit that
lacks the typical grapefruit flavor and bitterness. In this
respect, it closely resembles the Triumph, Mott (Aurantium) and Royal
varieties. Of unknown origin, Imperial is presumed to be an
introduction from Florida made about 1901 by the R. M. Teague Nurseries
of San Dimas, California. It never attained commercial
importance and is included here primarily because of its use in the
early citrus breeding program at the University of California Citrus
Research Center, Riverside.
Jackson
Jackson is a virtually seedless sport of Triumph with its
characteristic tenderness of flesh, juiciness, and mild
flavor. It was found as a limb sport on the property of H.
Jackson at Karino, eastern Transvaal, about 1945. It was
considered highly promising in South Africa and was planted to some
extent, but has proven to be very susceptible to the widespread
stem-pitting virus disease and hence is no longer much planted.
McCarty
McCarty is an old seedy variety of high quality that was popular for
some decades in the early history of the Florida industry. A
few orchards still exist. Hume (1926) considered it to be
somewhat distinctive in that the fruit is borne singly rather than in
clusters. Of unknown origin, it came to light at Rockledge,
Florida, about 1886 and was named for C. T. McCarty of Eldred, who was a
pioneer grapefruit grower.
McCarty has not been generally propagated outside of Florida.
Royal
This Florida variety has a relatively small, nearly round,
orange-yellow, seedy fruit of sweet flavor that lacks the typical
grapefruit bitterness and aroma and is suggestive of sweet
orange. While a distinctive variety, Royal has resemblances,
notably in flavor and other respects, to such varieties as Triumph,
Imperial, Mott and Leonardy, which suggests that they comprise a natural
group and may possibly be grapefruit-orange hybrids (orangelos).
Royal is said to have come originally from Cuba but was named and
introduced in 1892 by the Royal Palm Nurseries of Oneco,
Florida. It was grown commercially for several decades but
has not been planted for many years.
Shambar
Shambar is a seedless, pink-fleshed fruit that resembles Redblush
(Ruby) and has been reported to mature slightly earlier than Marsh or
Redblush and to exhibit somewhat better color and flavor than the
latter.
It was discovered by Alec
Barnes in 1936 as a limb sport of Marsh in an orchard of the Chace
Brothers (later American Fruit Growers Company) at Corona,
California. It was first described by A. D. Shamel of the
U.S. Department of Agriculture. Shambar was introduced
commercially in 1945, but has been little propagated.
Fruits Most Resembling the Grapefruit or Pummelo
Tangelos.—While
the tangelos (grapefruit-mandarin hybrids) of commercial importance
more closely resemble mandarins than grapefruits, there are some of
which the reverse is the case and hence they fall into this
group. The most important or interesting of these synthetic
hybrids appear to be the following:
K-Early
Fruit medium size, slightly subglobose; color yellowish-orange; seedy;
rather acid. Very early maturity. Somewhat
resembles the Orlando in appearance.
K-Early is sometimes incorrectly called Sunrise, a
name preempted by an older, very different, and little-known
tangelo. This variety is one of the first hybrids created by
Webber and Swingle of the U.S. Department of Agriculture in Florida, and
originally was not considered worthy of
introduction. Approximately two decades ago, it attracted the
attention of John Kauffman, Sr. of the Grand Island Nurseries at
Eustis, Florida, who was impressed by its very early coloring and
maturity and propagated trees for commercial planting about
1945. Although of comparatively poor quality, the high market
returns it has received have stimulated both interest and planting in
recent years.
Pearl
Fruit medium-small, slightly oblate; color yellow;
seedy. Rind comparatively smooth, thin and tightly adherent;
axis solid. Flesh tender, juicy; flavor pleasantly
sweet. Medium-early in maturity and loses quality if left on
tree past maturity.
Tree vigorous, spreading, drooping, and somewhat alternate bearing.
Pearl is similar in parentage to Allspice
and was released in 1940 (Frost, 1940). It is unattractive
and too small in all but the hottest climates but may be suitable for
home use.
Pina
The Pina variety produces an early ripening, seedy, grapefruit-like
fruit of medium-large size. The tree is lacking in
vigor. Originated from the same Duncan grapefruit and Dancy
tangerine cross that produced Minneola and Seminole, Pina has not
achieved commercial importance.
Sampson (fig. 4-64)
Fruit medium-sized, globose to slightly obovate; often somewhat necked;
color orange-yellow; seedy. Rind smooth, thin, relatively
adherent; axis semi-hollow. Flesh color dull orange; juicy,
somewhat acid; flavor with distinctive bitterish tang. Late-midseason in maturity. Seeds highly polyembryonic.
Tree vigorous, spreading, large, and productive; leaves distinctive, cupped, and boat-like
Sampson is a grapefruit and Dancy tangerine hybrid resulting from a
cross made in 1897 by Swingle in Florida. It was named and
described by Webber and Swingle of the U.S. Department of Agriculture in
1904. It has never attained commercial importance, except as
a rootstock to a limited extent, but is still grown somewhat as an
ornamental and an oddity.
Sunrise
See under K-Early.
Sunshine
Fruit large, grapefruit-like, slightly subglobose to somewhat oblong;
color pale orange; seedy. Flesh orange-colored; flavor
acid. Maturity very late.
Tree vigorous and upright.
Of the same parentage as Pina, Minneola, and Seminole, Sunshine has not
achieved commercial importance, but is said to be promising as a
rootstock in Florida.
Wekiwa (Pink tangelo)
Fruit medium-small, spherical to obovate or pyriform; color pale
yellow; seeds comparatively few. Rind medium-thick, smooth,
and fairly adherent; axis solid. Flesh tender, juicy; flavor
sweet and mildly acid, becoming unpleasant when
overripe. Under favorable conditions rind pink-blushed and
flesh amber-pink. Early in maturity.
Tree lacking in vigor but productive; leaves small and rounded-oval.
Wekiwa is a hybrid of grapefruit and Sampson tangelo and, therefore, is
in reality a tangelolo. It has not achieved commercial
importance but is of interest as a novelty and because of its pink rind
coloration.
Orangelos.—If Chapot (1950a)
is justified in his conclusion that certain so-called grapefruit
varieties such as Imperial, Royal, and Triumph are in reality natural
hybrids between the orange and grapefruit, they would obviously, fall in
the orangelo category. Since this view is not generally
accepted and since such varieties differ so little, if at all, from the
pure grapefruits, they have been included with the grapefruits.
The fruit described below is considered by authorities familiar with it to be a natural orangelo.
Chironja
Fruit large (grapefruit size), broadly obovoid to pyriform: low neck or
broad somewhat furrowed collar; few-seeded, seeds strongly
polyembryonic. Rind medium-thin, smooth, moderately adherent
but readily peelable; color bright yellow at
maturity. Segments about 10; axis medium-large and
semi-open. Flesh color yellowish-orange; tender, very juicy;
flavor mild, lacking the bitterness of the
grapefruit. Midseason in maturity and fruit holds well on
tree.
Tree vigorous, large, and
grapefruit-like; leaves broadly winged, somewhat cupped, and margins
irregularly undulate. Fruits usually borne singly rather than
in clusters characteristic of grapefruit.
Chironja recently came to notice in Puerto Rico and exhibits
resemblances to both the orange and grapefruit, particularly to the
latter. The name represents a combination of Chi(na), the
local term used for the sweet orange, and (to)ronja, the Spanish word
for grapefruit.
According to Moscoso
(1958), from whom the characterization above is adapted, this fruit
first came to his attention in 1956 as a wild seedling tree in the
mountainous Angeles and Caguanas rural section of Utuado
municipality. Subsequently, however, other seedling trees
were found in isolated areas of the coffee zone. The
parentage of Chironja is unknown, but it is thought to be a natural
orangelo of local origin. The fruit has attracted interest
and limited quantities are available in the principal local market.
Presumed Pummelo Hybrids.—Presumably
largely because of its monoembryonic nature, natural hybrids of the
pummelo abound in the Orient and exhibit a remarkable diversity of
characters. As might be expected, some of them have been
found to possess desirable or acceptable qualities as fresh fruits and
have come into commercial use. The most important of these
appear to be the Natsudaidai and Hassaku in Japan and the
so-called Poorman orange, Smooth Seville, and Wheeny grapefruit in
Australia and New Zealand. Of minor importance is the
so-called Tiniura tangelo of New Zealand.
Hassaku (Hassaku Mikan or Zabon) [C. hassaku Hort. ex Tanaka] (fig. 4-65)
Fruit medium-large (9-10 cm in diameter), slightly oblate; both ends
somewhat depressed; seedy and monoembryonic. Rind
color orange-yellow; medium-thick; surface somewhat coarsely pebbled;
moderately adherent. Segments numerous; axis large and
semi-hollow at maturity. Flesh color light yellow; somewhat
coarse-grained; lacking in juice; flavor good. Early
midseason in maturity and stores only moderately well.
Tree vigorous, upright, virtually thornless; leaves large and
pummelo-like, but petiole wings narrower, approaching sweet orange.
Hassaku is said to have originated as a chance seedling in Hiroshma
Prefecture, Japan. It was noted and named in 1860, but was
not propagated and planted commercially until about 1925. In
1964, Japanese planting was reportedly in excess of 2,500 acres, mostly
in the prefecture of its origin. During the 1960's, however,
it has been planted increasingly elsewhere.
Its characteristic strongly suggest pummelo-mandarin parentage with pummelo predominant.
Kawano
See under Natsudaidai below.
Natsudaidai [C. natsudaidai Hayata] (fig. 4-66)
Fruit medium to medium-large (grapefruit size), broadly obovate to
oblate; sometimes with very short collared neck and apex slightly
depressed; moderately seedy. Color
yellowish-orange. Rind medium-thick; surface coarsely pebbled
slightly rough; moderately seedy. Color yellowish
orange. Rind medium-thick; surface coarsely pebbled,
sometimes slightly rough; moderately adherent (peels
readily). Segments fairly numerous (12); axis large and
semi-hollow at maturity. Flavor acid and
refreshing. Late in maturity (summer-maturing in most
climates). Holds well on the tree and improves in storage.
Tree vigorous and upright-spreading with few stout thorns; leaves
large, dark green, and mandarin-like.
The Natsudaidai tree is reported to be less cold resistant than the
satsuma mandarin in Japan. Its behavior there and in the
coastal regions of southern California indicates a heat requirement for
fruit maturity somewhat less than that of the grapefruit and comparable
with the so-called Poorman orange and Wheeny grapefruit of New Zealand
and Australia, both of which attain acceptable quality in climates too
cool for satisfactory maturity of the
grapefruit. Nevertheless, even at full maturity the
Natsudaidai remains too acid for some palates.
The original seedling tree of this fruit is said to have been found in a
garden in Yamaguchi Prefecture, Japan, toward the end of the 17th
century and is reported still alive. The value of its
late-ripening characteristic was not appreciated until approximately a
century later and is reflected in the names most commonly used for it (natsu means summer). Other names include natsumikan, natsukan, daidai mikan, and Japanese summer grapefruit or orange.
Natsudaidai is extensively grown in the Japanese coastal regions of
mildest winters and is currently second in importance only to the
satsuma mandarin. The Statistical Yearbook of the
Japanese Ministry of Agriculture and Forestry reports that the 1961
acreage was approximately 28,000 with a production of about
173,000 tons, accounting for some 15 per cent of the total production of
Japanese citrus fruits (see chap. 2, table 2-1, pp. 42-43 [text
version, Revised Ed.]).
The
Natsudaidai exhibits characters of the pummelo or sour orange and the
mandarin. In the writer's opinion, the evidence supports the
conclusion of Tanaka (1954, p. 91) that the pummelo is involved in its
parentage.
Numerous unnamed clones
and selections are grown, some of which exhibit minor differences, but
only two derivative varieties—Kawano and Tajima—have been named and
propagated commercially. The former differs appreciably from
the common Natsudaidai only in the fact that the fruit is less acid (and
hence sweeter), matures much earlier, and loses quality if held on the
tree after maturity. It is said to have originated as a limb
sport in an orchard in Oita Prefecture about 1905 and was named and
registered in 1950. It is currently recommended for planting
in several districts. Tajima is a new and very juicy,
late-ripening, high acid variety of much less importance, but considered
to be promising.
Morrison (Morrison Seedless)
See under Poorman below.
New Zealand
See under Poorman below.
Poorman (Poorman Orange, New Zealand Grapefruit) (fig. 4-67)
Fruit medium-large, oblate to broadly obovate to nearly globose; seeds numerous but monoembryonic.
Color pale orange-yellow at maturity (deeper than any of the
grapefruits). Rind medium-thick with fairly rugose surface
(somewhat more so than Wheeny). Flesh color yellowish-orange;
coarse-textured, juicy; flavor pleasantly subacid with trace of
bitterness. Very early in maturity (as compared to the
grapefruits). Much earlier than Wheeny, but holds on tree
exceptionally well without loss in quality.
Tree vigorous, large, and prolific; leaves dark green, with petioles
suggestive of mandarin or bitter orange rather than
grapefruit. Most Australian selections and some in New
Zealand exhibit a peculiar and distinctive bark condition, which in
California appears to be associated with dwarfing. Surface of
trunk and main limbs markedly rough and grayish-black in color;
dull-black streaks on smaller branches and twigs.
Although obviously not an orange, the names Poorman Orange or Poorman
are employed for this fruit in Australia, where it first came to
notice. Since it most resembles the grapefruit in both
appearance and use and is the citrus fruit most extensively grown in New
Zealand, the preferable name for this interesting and distinctive fruit
would appear to be New Zealand Grapefruit.
A total heat requirement considerably lower than for any of the true
grapefruits is indicated by the earlier maturity of Poorman and the fact
that it ripens in New Zealand and parts of southern California where
there is insufficient heat for any of the present grapefruit varieties.
That Poorman originated in the Orient is suggested by Bowman's
statement (1956) that it was brought to Australia (presumably the fruit)
from Shanghai by a Captain Simpson. The earliest description
of record, given in a New South Wales nursery catalogue of 1820,
indicates that the original introduction might have been a shaddock
(pummelo); hence, the possibility exists that Poorman is of Australian
origin. Since the seeds are monoembryonic, early references
to the existence of clones varying appreciably in fruit characteristics,
and to the possibility of hybrid origin, are
understandable. According to Bowman (1956), this fruit was
taken to New Zealand by Sir George Grey, who established his home on
Kawau Island about 1855. About 1861, Grey provided
propagation materials to John Morrison of Warkworth, for whom the clone
currently most widely grown in New Zealand was named.
Although generally distributed and commonly available in the markets,
Poorman has not achieved much commercial importance in Australia,
presumably because of the availability of grapefruits. In New
Zealand, however, where grapefruit does not succeed, under the name of
New Zealand Grapefruit it has become the principal citrus fruit grown
and currently comprises about 85 per cent of the so-called grapefruit
acreage, the balance consisting of the low-heat-requiring Wheeny
variety. The 1962-63 crop of 167,000 bushels (40-1b) is said
to have accounted for 55 per cent of the total citrus production in New
Zealand. While principally used as a breakfast fruit, the
juice is also canned and the immature fruits are extensively used for
marmalade purposes. Morrison (Morrison Seedless) is
considered to be the best clone. It is seedless, however,
only in the absence of cross-pollination.
Almost certainly Poorman is a pummelo hybrid and probably a natural
tangelo. The fruit has some resemblance to the Attani of India and the Natsudaidai and Asahikun of Japan.
Smooth Seville (Smooth Flat Seville) (fig. 4-68)
Fruit similar to Poorman in size, form, and flavor, but rind surface
very smooth; both rind and flesh color reddish-orange; seeds exhibit low
polyembryony (usually one, occasionally two embryos).
Tree and foliage similar to Poorman but tree commonly more vigorous and
larger. Younger branches also exhibit dark bark streaks
characteristic of Poorman. Distinctive rough bark condition
on trunk and main branches which affects some Poorman selections not
observed so far on Smooth Seville trees.19
This is an old Australian fruit that is thought to have originated as a
seedling of unknown parentage and has generally been regarded as a
sweet orange and grapefruit hybrid. Its age and numerous
resemblances to Poorman, however, suggest that it may be of similar
origin and possibly a sister seedling.
Like Poorman, Smooth Seville has a lower heat requirement for maturity
than the grapefruit and hence ripens earlier and serves as a
satisfactory substitute.
Tajima
See under Natsudaidai.
Wheeny (Wheeny Grapefruit) (fig. 4-69)
Fruit large, oblate or very broadly obovate to globose; both ends
depressed, with small radially-furrowed basal cavity and broad, shallow
apical basin; moderately seedy but monoembryonic. Color
pale to light yellow. Rind medium-thin with moderately
rugose surface (not smooth as are most grapefruits). Flesh
straw-colored; coarse textured but very juicy; flavor good but acid
(virtually indistinguishable from some
grapefruits). Medium-early in maturity (as compared to the
true grapefruits).
Tree vigorous,
spreading, large, and productive with tendency to alternation in
bearing. Leaves longer and more pointed than most grapefruits
and somewhat bullate (puckered), with comparatively narrow petiole
wings.
A lower total heat requirement
than for grapefruit is indicated by the fact that in both New Zealand
and coastal southern California Wheeny ripens satisfactorily in climates
too cool for any of the true grapefruits. Under conditions
favorable to grapefruit, it matures earlier and develops quality equal
or superior to many grapefruit varieties.
This variety originated as a chance seedling at Wheeny Creek near
Kurrajong, New South Wales, Australia, and was named by R. J. Benton,
government citrus specialist. It is of principal importance
in New Zealand, however, where it was introduced about 1935 and now
constitutes about 15 per cent of the so-called grapefruit acreage, the
balance being provided by the New Zealand Grapefruit or Poorman
Orange. Under heat-deficient climatic conditions in Australia
and New Zealand, Wheeny is a summer-maturing variety.
While the fruit is grapefruit-like in most respects, the monoembryonic
nature of the seeds and some of the other characters suggest that it is
probably a pummelo hybrid.
Pummelo-like Fruits of Minor Importance.—Of
limited commercial importance in Japan are several other pummelo-like
fruits either known or thought to have originated as chance
seedlings. Among them are the following:
Banôkan [C. grandis var. banokan
Tan.]—A medium-large, yellow, oblate to subglobose, thick-rinded,
juicy, subacid fruit of good flavor and late maturity. Both
tree and fruit are very much like pummelo.
Hyûganatsu [C. tamurana Tan.]—A
medium-sized, light yellow, globose to oblong, juicy, sweet-flavored,
moderately seedy, late-ripening fruit which requires cross-pollination.
Kinkôji [C. obovoidea Takahashi]—A
medium-small, yellowish-orange, subglobose to obovoid, pleasantly
flavored fruit of medium-late maturity and with highly polyembryonic
seeds. An old fruit of unknown origin, but apparently a
pummelo-mandarin hybrid.
Kinukawa [C. glaberrima Tan.]—A
medium-sized, bright yellow, oblate to globose, juicy, sweet-flavored
pummelo-like fruit of midseason maturity. Monoembryonic.
Not commercially important but of interest in the category of pummelo-like fruits are the Asahikan (C. asahikan Tan.) of Japan and the Attani (C. rugulosa Tan.) of India.
COMMON ACID MEMBERS—CITRON, LEMON, AND LIME
That the citrons, lemons, and limes constitute a natural group is
indicated by the distinctive characters they possess in common and their
numerous resemblances. Indeed, the earlier botanists, almost
without exception, placed them in the same species and considered the
lemon and lime to be botanical varieties. The most
distinctive fruit characters of the acid members are high acidity (all
three have sweet or acidless forms, however) and an oval to elliptical
shape with areolar mammilla or nipple (sometimes suppressed,
however). All are more or less everflowering, everbearing,
and highly sensitive to cold.
The
differences the acid members exhibit are so numerous and striking,
however, that they have long since been separated into
species. Indeed, the limes are generally considered to
comprise several species.
In
comparison, therefore, this natural group exhibits a much wider range of
variation than any other citrus group. Thus, the citron is
among the largest and, because of its very thick and dense rind, is the
heaviest of all citrus fruits, whereas the Indian sour lime is among the
smallest and thinnest-skinned. On the other hand, the citron
plant is a thick-stemmed shrub or small tree with large elliptical,
nearly round-pointed leaves, while the Indian sour lime is a good-sized,
fine-stemmed tree with very small lanceolate, sharp-pointed
leaves. The lemons and some of the limes are intermediate
between these extremes. Finally, the citrons are
monoembryonic, the lemons only slightly polyembryonic, and some of the
limes highly polyembryonic.
In
northeastern India and adjoining portions of their general area of
origin, natural hybrids with characters of the citron or lemon are
common and there can be little doubt that they have contributed to the
list of distinctive and little-known Indian fruits (Hodgson, Singh, and
Singh, 1963). Among those fruits in which citron characters
are discernible are the amilbed and sadaphal and among those in which lemon characters are evident are the galgal and jambhiri or jamberi. Citron-like fruits of the Western World include the lumias of the Mediterranean and the so-called Ponderosa lemon and Cuban shaddock.
Lemon varieties in which citron characters are discernible have long been known and include the pat nebu, Nepali Oblong or Assam and others of India, Interdonato of Italy, and San Jeronimo of Portugal. Lemon-lime hybrids are represented by the Perrine lemonime of Florida.
Citron (Citrus medica L.)
The citron is the cedro or cedrone of Italy, cidra or poncil of Spain, cedrat of France, and bushukon of Japan. Unfortunately,the fact that the modern French word for lemon is citron has led to considerable confusion and ambiguity in the literature.
That this fruit probably had its origin in northeastern India and
adjoining areas is suggested from the facts that it is found growing
wild in parts of that region and that natural hybrids in which its
characters appear are abundant there. It seems early to have
spread to Media and Persia where it became known to the Greeks and
somewhat later to the Romans, who considered it to be indigenous there
and called it the Persian or Median apple (from which its species
designation was derived). It must have reached the Holy Land
not long thereafter. Most Jewish scholars agree that the hadar or
"goodly fruit" of the Bible (Lev. 23:40) is the citron, which, if true,
would date its earliest reference in the Holy Land to the thirteenth
century B.C. (see chap 1, this work).
There can be little doubt that the citron was the first citrus fruit
brought under cultivation and the first to reach the Mediterranean and
to become known to Europeans (Tolkowsky, 1938). Evidence
indicates that it was introduced into Italy in the first century (see
chap. 1, this work). Like
most of the other citrus fruits, it was taken to the West Indies and to
Brazil soon after the discovery of the New World. It was
early brought to California from Mexico by the Spanish Mission fathers
(Butterfield, 1963).
The citron is
highly distinctive in both plant and fruit
characteristics. The plant is a comparatively short-lived,
thick-stemmed, straggly growing, thorny shrub or small tree with light
gray bark and relatively soft wood. It is highly sensitive to
frost injury and recovers slowly, if at all. The leaves are
large, oval to oblong, with rumpled blades and serrate margins, and
short, wingless petioles not visibly articulated with the
blades. The flowers are large, purple-tinged or not, with a
variable and often high proportion male (by pistil abortion), and are
produced throughout the year. The fruits are large to very
large and of variable form, but usually oblong and blunt-pointed, with
pronounced mammilla and often with persistent style. The
yellow rind is very thick, fleshy and tightly adherent (cannot be peeled
by hand because the carpellary membranes are separated by albedo
tissue, fig. 4-70). The
rind has a smooth but often bumpy surface. The rind oil is
pleasantly aromatic. The flesh is small in amount, firm, and
lacking in juice. The juice is either acid or
sweet. The seeds are numerous, monoembryonic, and distinctive in form, with a pronounced beak and white cotyledons.
Since the fruit is virtually indelible and neither tree nor fruit is
particularly ornamental, the question is often raised as to why the
ancient Greeks and Romans held the citron in such high esteem as
indicated in their early literature. It would appear that the
reasons were that the fragrance of the fruit is delicate, penetrating,
and lasting, and it was the only citrus fruit with which the Romans were
acquainted. For many centuries its main use seems to have
been as a perfumant and moth repellant.
Much later, when sugar became available, there developed the
utilization on which the present commercial industry is based—candying
of the peel. In candying, the fruits are cut into halves, and
the pulp is removed. The halves are placed in brine
(commonly sea water) for a month or thereabouts, during which a
fermentation occurs. The halves are then removed, washed, and
held in a somewhat stronger brine until used for
candying. The fruit is commonly exported in brine to buyers
in the markets where it is to be candied, which are principally in
France, Great Britain, and the United States. The candied
peel is an essential constituent in certain cakes and confections.
Much the oldest use of the citron, although obviously highly limited,
is that previously mentioned, namely, in connection with the orthodox
observance of the Jewish Feast of Tabernacles (Succoth). The
Etrog or Ethrog required in the ceremonies is a small but relatively
mature citron which, according to Chapot (1950b), must be fresh
(not preserved), clean, without defects such as wounds or scars, and
symmetrical with a persistent style. The Etrog must also come
from a tree which has not been grafted (cutting or
seeding). While there is an Etrog variety, any citron fruit which meets these requirements is said to be acceptable. Such fruits are often expensive.
Because of its sensitivity to frost and heat injury, the commercial
culture of citron is restricted to regions where the winters are mild
and summer temperatures are not excessively high. Because of
the premium received for unblemished fruits, it is especially subject to
loss of quality from wind damage. The Mediterranean areas
where these requirements are best met consist primarily of the southern
portion of the Italian and Grecian peninsulas and nearby
islands. Thus, the principal citron-producing countries are
France (Corsica), Italy (Calabria, Sicily, and Sardinia), and Greece
(mainly Crete and other islands), although small quantities are produced
elsewhere. Corsica is said to account for about a third of
the world supply, and total plantings in Italy are currently estimated
at about 3,000 acres.
The citron has
been successfully grown and processed in southern California, but its
culture has not persisted because of inability to withstand competition
from the Mediterranean.
Citron
culture as practiced in the Mediterranean area exhibits several features
of special interest to horticulturists: (1) it is largely located on
relatively steep, terraced slopes; (2) the trees are mainly propagated
from cuttings; and (3) protection against frost and prevention against
wind injury are commonly provided by means of a pole framework on which
straw matting is fastened during the winter and to which the branches of
the trees are tied to prevent breakage and injury to the fruit from
swaying under wind action.
While the
citron exhibits a wide range in fruit size and form, including the
famous fingered citron (fig. 4-71)
of the Orient, all varieties appear to fall into two natural groups—the
acid or sour citrons and the acidless sweet citrons. The
former are distinguished by flowers that are purple in the bud and
purple-tinged when open, pink-colored new shoot growth, acid pulp, and
seeds with a dark-colored inner seed coat and chalazal
spot. In contrast, neither flowers nor shoot growth of the
sweet citrons exhibit pink coloration, the pulp is lacking in acid and
hence sweet, and the inner seed coat is colorless and the chalazal spot
light yellow.
Major Acid Citron Varieties.—The Diamonte and the Etrog are the two acid citron varieties of greatest significance. They are described below.
Atrog
See under Etrog.
Cedro Liscio
See under Diamante below.
Diamante (Cedro Liscio) (figs. 4-7 [sic, i.e., 4-70] and 4-72)
Fruit large,
long-oval to ellipsoid; basal cavity furrowed and surrounded by low
collar; apex broadly nippled; and seedy. Color lemon-yellow
at maturity. Rind very thick and fleshy; surface smooth and
sometimes indistinctly lobed or ribbed. Flesh crisp; lacking
in juice, but acid, like lemon.
Tree
small, open and spreading, medium-thorny with some large, stout spines;
buds, flowers, and new growth purple-tinted.
Presumably of local though unknown origin, Diamante is the principal
variety of Italy and according to Casella (1928) is considered to be the
best. It was introduced into the United States in
1898. Italian and Sicilian are California introductions that
are similar to Diamante.
Ethrog
See under Etrog below.
Etrog (Atrog, Ethrog)
Fruit medium-small, ellipsoid to fusiform or lemon-shaped; commonly
with fairly distinct neck and prominent apical nipple; frequently with
persistent style; seedy. Lemon-yellow at
maturity. Rind thick and fleshy; surface slightly ribbed,
somewhat rough, and bumpy. Flesh crisp and firm; low in juice
content; flavor acid.
Tree smaller
and less vigorous and productive than most citrons; leaves more
round-pointed and downward cupped. Flower buds, flowers, and
new growth purple-tinted.
Under the
name of Etrog and its synonyms, at least two introductions from
Palestine have been received in the United States which correspond with
the above general characterization, although there are minor
differences. They are evidently selections made for ritual
purposes, though, as previously mentioned, any citron fruit that meets
the specified requirements is acceptable. In neither has the
per cent of persistent styles been above average.
Jericho Ethrog is said to be currently the most widely planted citron
in Israel and is characterized by relatively small fruit size, oval
shape, and deeply corrugated rind surface. It is reported to
be of local origin and to reproduce true to type from seed even though
monoembryonic, in which respect it is similar to several of the United
States introductions.
From the
materials available in California, there appears to be little
justification for Swingle's classification of this fruit as the
botanical variety ethrog (see chap. 3, this work).
Italian
See under Diamante.
Jericho
See under Etrog.
Sicilian
See under Diamante.
Minor Acid Citron Varieties.—While
there are a number of varieties of the acid citron group, only two of
these were considered sufficiently important in judging the literature
to warrant specific description in the previous
subsection. Some of the better known minor varieties are
briefly discussed below.
Poncire is
doubtless the oldest known citron variety for it was described by Risso
and Poiteau (1818-1822). The word poncire is from an
old dialect of southern France (Provence) and means Syrian
apple. Saigon is reported in Algeria and Morocco and to judge
from the name must have been introduced from
Indo-China. Earle, described and named by Webber (1943),
closely resembles Diamante. It was introduced from Cuba in
1914 and named for the owner of the orchard from which it was
selected. China (Chinese or China lemon) is a small-leafed
citron, the fruits of which are also small, lemon-shaped, roughly
corrugated, and worthless. Supposedly from China, it was
employed as a rootstock in the early history of the citrus industry in
California but was soon found unsuitable and abandoned.
A most unusual and interesting citron is the fingered or Buddha's Hand citron (fig. 4-71) of the Orient (bushukan
of Japan), where it has been prized for centuries, especially in
Indo-China, China and Japan. As the name indicates, the fruit
is apically split into a number of fingerlike sections, somewhat
resembling a human hand. There appear to be two clones—one in
which all the fruits are deeply fingered and lacking in flesh
development and seeds, the other in which only part of the fruits are
fingered and the rest are corrugated, lacking in flesh, and contain
seeds hanging free in the locules. Both are typical acid
citrons in all other respects and would seem to constitute clonal
varieties rather than the botanical variety sarcodactylis as they are classified by Swingle (see chap. 3, this work).
Sweet Citron Varieties.—The
only widely-grown sweet citron variety is the Corsican, which is
described below. The literature does not disclose other
sweet-fruited varieties of general distribution. That there
are some varieties of local importance is indicated by Chapot (1950b and 1962a),
who described two of Moroccan origin: Assads and
M'Guergueb. The California introduction Dulcia, the fruit of
which is smaller than the Corsican and almost flat, is another variety
in this local category.
Citron of Commerce
See under Corsican below.
Corsican (fig. 4-70 and 4-73)
Fruit large, ellipsoid to very slightly obovate; basal area slightly
depressed and radially furrowed; apical nipple suppressed or indistinct
(less prominent than in Diamante); seedy. Color
lemon-yellow. Rind very thick and fleshy; surface rather
rough, bumpy, and commonly somewhat ribbed. Flesh crisp and
solid; lacking in juice; flavor sweet (without acid).
Tree small, open and spreading; medium-thorny with some large, stout
spines (vary much like Diamante); buds, flowers and new growth not
purpie-tinted.
This variety is said
to be the best and most important citron in Corsica and presumably
originated there, although its history is unknown. It was
introduced into the United States about 1891 and distributed under the
name Corsican. Citron of Commerce in California is
indistinguishable.
Fruits Resembling the Citron.—There
are numerous fruits in which citron characters are strongly
pronounced. The lumias of the Mediterranean basin are natural
hybrids in which acid citron or lemon and pummelo characters are
evident. According to Chapot (1950a), they are
characterized by fruits of large size, commonly somewhat pyriform, with
highly acid flesh of greenish color, large purple-tinged flowers, and
young shoot growth both pubescent and purple-tinted. Chapot
states that the principal clonal varieties are Poire du Commandeur,
Citron de Borneo (Chapot, 1964d), and Pomme
d'Adam. They are of ancient and unknown origin, presumably
Italian, and are grown only as curiosities or ornamentals.
The giant-fruited Sui Khar citron of Punjab State (Hodgson, Singh and Singh, 1963), the Kabbad citron of Damascus (Chapot, 1963f), and the yemmakaipuli of Coorg (India) also appear to fall in this group.
Only two of the fruits resembling the citron, however, are of
sufficient importance or interest, to warrant specific
descriptions. These are the so-called Cuban shaddock and the
Ponderosa lemon.
American Wonder
See under Ponderosa.
Cuban (Cuban Shaddock or Lemon)
Fruit large to very large, globose to obovate; color [sic]
depressed and deeply furrowed at base; apex rounded or depressed, but
sometimes with low and indistinct nipple; seeds
numerous. Color lemon-yellow at maturity. Rind
thick and spongy; surface rough, bumpy, and commonly somewhat
furrowed. Flesh color yellowish-green; coarse-textured,
juicy; flavor acid.
Tree vigorous,
upright, spreading, large, thorny, and productive; foliage
dense. Leaves large, oblong-elliptic, and
blunt-pointed. Flowers and new growth not
purple-tinted. Tree sensitive to cold.
While the Cuban shaddock somewhat resembles the pummelo in appearance,
most of the characters are those of the citron or lemon. As
the name suggests, this fruit was introduced from Cuba, where it is
referred to as a shaddock and for a time was recommended as a
rootstock. It remains only a horticultural curiosity.
Ponderosa (Ponderosa Lemon, Wonder, American Wonder) (fig. 4-74)
Fruit medium-large, obovoid; collar radially ribbed or furrowed or
short neck and low broad apical nipple; color lemon-yellow; seedy and monoembyonic. Rind
medium-thick and fleshy; surface smooth but slightly bumpy and
indistinctly ribbed. Flesh color pale green; juicy; flavor
acid. Fruits mature throughout year.
Tree small, round-topped, and productive; branches medium-thick and
theory; leaves large elliptical to oblong and
citron-like. Flowers and new growth
purple-tinged. Everflowering. Tree sensitive to
cold.
Both fruit and plant are clearly
citron in most respects, and there can be little doubt that Ponderosa
is a hybrid between citron and lemon. According to Webber
(1943), this variety originated about 1887 as a chance seedling
(presumably of lemon) grown by George Bowman of Hagerstown, Maryland,
and was named and introduced to the nursery trade in 1900. If
this account is accurate, the fruit from which the seed was obtained must have been of Italian origin.
Ponderosa is of importance primarily as an oddity and ornamental,
although the fruit can be used as a lemon substitute. It is
used somewhat as a tubbed plant in patios but most commonly as a
dooryard ornamental in California and Florida.
Wonder
See under Ponderosa above.
Lemon (Citrus limon [L.] Burm. f)
The lemon is the limone of Italy, the limon of Spain, and the citron of
France. The fact that the French name is the same as the
English name for a quite different, closely related fruit has led to
both confusion and ambiguity in the literature.
The lemon must have originated
in the eastern Himalayan region of India and adjoining areas, also the
home of the citron, for natural hybrids with citron and lemon characters
are abundant there. Indeed, most of the lemon-like fruits of
India exhibit citron characters to some degree. It is an
interesting fact, however, that lemons of the common Mediterranean type
have not been found growing wild in any part of that region or
elsewhere. For reasons that are not clear, possibly its more
recent origin, the lemon as we know it seems to have spread to the
Mediterranean and reached Europe much later than the citron (see chap 1,
p. 6).
From archeological evidence,
Tolkowsky (1938) has concluded that the lemon reached Italy by the end
of the second century and was among the fruits taken by the Arabs to
Spain prior to 1150 A.D. (see chap. 1, this work). It
is clear that the Arabs took the lemon to the Mediterranean and across
North Africa to Spain, for Arab writers of the twelfth century mention
it as among the citrus fruits grown there at that
time. It is also certain that tae Crusaders took it from
Palestine to southern Europe, Italy in particular, not long
thereafter. It is known that the lemon was among the fruits
taken to the New World by Columbus on his second voyage in 1493.
The lemon tree is vigorous, upright-spreading, and open in growth
habit. It attains large size under favorable conditions if
not controlled by pruning. Seedlings and most varieties are
comparatively thorny, with relatively short and slender
spines. The light-green leaves are lanceolate in form with
short, wing-margined petioles. The flowers, which occur in
clusters produced throughout the year, are large and purple-tinged in
the bud and on the lower surface of the petals. Many are
sterile because of pistil abortion, which varies greatly from bloom to
bloom and season to season. The new shoot growth is
purple-tinted.
The fruit
characteristics are so well known as scarcely to require
description. Mention should be made, however, of the
distinctive form and apical mammilla or nipple, the tight adherence of
the highly fragrant rind, and the high acidity of the pale,
straw-colored flesh.
Although more
resistant than the citron and limes to cold and heat, the lemon is much
more sensitive than the other citrus fruits of major importance, and
hence its commercial culture is restricted to subtropical regions of
mild winter temperatures. Relatively equable growing-season
temperatures are advantageous in that they seem to emphasize the
ever-flowering tendency and are favorable for
fruit-setting. As a consequence, the seasonal distribution of
the crop is such as to provide the maximum output during late spring
and summer, when prices are normally high and there is a minimum storage
requirement. Thus, in regions characterized by mild winters
and cool equable summers, marketable fruit is available throughout the
year with a minimum requirement for frost-protection and fruit storage,
both of which are expensive. These facts serve to explain
why, with minor exceptions, the principal commercial lemon-producing
areas of the world are in coastal locations of southern California,
Sicily, Greece, and Spain. By contrast, the picking season
generally in interior districts is shorter and a much higher
percentage of the crops come during the fall and winter, when prices are
usually lower and longer storage is required for the summer
markets. On the other hand, the fall and winter fruit ships
and stores well and is higher in acid content.
Lemons are little grown in semitropical and tropical
regions. In such regions, the sour lime is better adapted to
both heat and humidity and is generally preferred. In
addition, lemon size is undesirably large in relation to market demand,
rind diseases are prevalent, and storage is difficult and
expensive. If economically justifiable, however, it may be
horticulturally practicable to produce lemons for processing purposes in
such climates.
The fact that the
lemon is grown primarily for the acid it contains, a constituent which
is at its maximum prior to the attainment of horticultural maturity,
affords possibilities in fruit-handling which have found numerous and
important applications in practice. Indeed, development and
utilization of such handling methods are largely responsible for the
success of the California industry in supplying the needs of North
America and invading the highly competitive markets of
Europe. Specialized handling methods perfected in California
include:
1. Picking according to fruit size rather than maturity.
2. Maturity grading by means of separation according to color.
3. Curing of fruit prior to packing.
4. Regulated and controlled storage.
At each picking, all fruit which will not pass through a metal ring of
predetermined diameter is harvested irrespective of
maturity. By far the greater part of the crop is therefore
immature and of maximum acid content and storage life when picked.
Accurate separation of fruit into color grades is perhaps the most
important single operation in the packing house, for it determines the
curing possibilities and storage life of the fruit. Four
color grades are usually made—from "tree ripe" (yellow) with a storage
life of a few weeks only (generally sent direct to the processing
plant), through "silver" (yellowish-green) and "light green" to "dark
green," with a commercial storage life of six months or more.
Since freshly picked lemons are mostly immature, they are firm and
turgid and the rinds are thick and fleshy. They are therefore
highly sensitive to injury, resulting in rind spotting or
decay. Indeed, lemons should not be picked in early morning
when they are at a maximum turgidity or when there is water on the
fruit, for the escape of rind oil during handling may cause rind injury
followed by spotting. During storage, however, the rind loses
moisture, thins down, and becomes tough, leathery, and markedly
resistant to injuries from handling operations. Such changes,
usually associated with the development or intensification of the
yellow color, constitute the "curing" process, which greatly improves
the appearance of the fruit and contributes to successful long-distance
shipment.
Curing proceeds slowly at
the usual storage temperatures of 55º F to 60º F and relative humidities
of 75 to 85 per cent, but it is normally completed long before the
fruit is packed and shipped. Curing can be markedly
accelerated, however, by raising the temperature and adding ethylene gas
in dilute concentration to the storage atmosphere, thus converting
highly immature, dark green fruit to an attractive, salable product in a
matter of weeks.
The use of
regulated or controlled storage and the availability of means for
accelerating curing—all prior to packing—provide the flexibility in
packinghouse operations necessary for successful adjustment between the
highly variable and uncontrollable receipt of fruit from the orchards
and the even more variable and uncontrollable market demand.
California's highly important handling practices, supplemented by the
more recent development of treatment of the fruit with 2,4-D to reduce
the tendency to abscission of the "buttons" (fruit calyces) during
curing and the use of gibberellin sprays to retard the maturity of the
fruit, are almost unique in the lemon industry.
The most unusual orchard management practice in lemon culture is the forcing or verdelli
(summer lemons) treatment which has been employed in Sicily for many
decades. Its purpose is to materially accentuate the late
summer bloom (August-September) and thus increase the crop, which
matures the following summer when prices are normally
high. This is accomplished by withholding irrigation during
the summer (June-July) until the trees have wilted, followed by an
application of nitrogenous fertilizer and renewal of
irrigation. If the trees have been sufficiently stressed, the
result is a greatly increased late summer bloom and a summer or verdelli crop
the following year and a reduced winter crop. A deeper than
average cultivation is sometimes employed to supplement the suspension
of irrigation. Unless carefully controlled, this practice is
harmful. For this reason, it is usually employed on a
rotational basis, every other year or every third year. A
somewhat similar treatment is used for the production of summer sour
limes in the Faiyûm oasis of Egypt and for the control of the blossoming of oranges and mandarins in central and southern India.
The lemon is still used primarily as a fresh fruit, although in the
United States the trend of shipment to the markets has been downward for
some years past. Likewise, the per capita consumption of
lemons in all forms has slowly declined. The principal fresh
fruit uses of the lemon are for the making of lemonade, as a garnish for
fish and meats, and for a wide variety of culinary preparations—pies,
cakes, ices, and the like—and as flavoring for candies, jellies, jams,
and marmalades. Lemon juice is the principal product, of
course, and its preparation in various forms—fresh and preserved,
bottled, canned, and concentrated—has expanded greatly in recent
decades, The product which has enjoyed the greatest success is canned
frozen lemonade concentrate. Lemon juice is also widely used
in the preparation of proprietary soft drinks, generally bottled but
sometimes canned. Lemon juice possesses special dietetic and
medicinal values associated with its vitamin content and even enjoys
certain cosmetic uses. In general, these latter uses require
comparatively little fruit or juice.
The principal byproducts obtained from the fruit are citric acid from
the juice and pectin and lemon oil from the rind. Pectin and
lemon oil are currently of principal importance, because of the
competition to citric acid from the juice provided by synthetic citric
acid produced by controlled sugar fermentation, and have found a wide
variety of industrial, culinary, and cosmetic uses. A number
of pharmaceutical products using the lemon have also been
developed. In California, however, the value of the return
from byproducts has rarely, if ever, equalled the cost of fruit
production.
It seems likely that
lemon culture will continue to decrease in relative importance in the
citricultural world for the following reasons: (1) the lemon is not
palatable as a fresh fruit; (2) its principal constituent, citric acid,
can be produced synthetically at low cost; and (3) the returns from
byproducts rarely equal the production cost of the raw material.
Commercial lemon culture developed first in Italy, mainly in Sicily,
and until a few decades ago that country led in
production. Steady and rapid increase in California, however,
and a marked decrease in Italy because of the mal secco disease put the
United States in the lead shortly before World War II. In
1961-62, the California and Arizona crop was approximately 16.7 million
boxes (76-1b) in comparison with 14.3 million boxes in
Italy. Acreage in California decreased by 23 per cent (11,500
acres) in the decade ending in 1964. With both acreage and
production increasing in Sicily, Italy had regained the leading position
by the 1964-65 season. The United States and Italy accounted
for about three-fourths of the world crop of 48 million boxes in
1965. Spain, Greece and Argentina each produced from 2 to 3
million boxes and Turkey, Lebanon, and Chile exceeded 1 million
boxes. There is some commercial production in virtually all
of the other Mediterranean countries and also in Australia and South
Africa.
With respect to description
and identification, the lemon presents especially difficult
problems. Not only is the fruit from a given bloom highly
variable in its characteristics, but, as pointed out elsewhere, the fruit from different blooms commonly exhibits greater differences than those which occur between varieties in the same bloom. Insofar
as fruit characters are concerned, the varieties grown in California
and many of those in the Mediterranean basin are remarkably alike, if
not identical. The principal exceptions are those, such as
Interdonato of Italy and a few others, which are citron-like in certain
characters and presumably of hybrid origin, and Arancino and Lunario of
Italy and a few others of distinctive form. Finally, the rind
characteristics of the immature fresh lemon are materially modified
during curing and storage. As a consequence, for many if not
most varieties, it is difficult to prepare accurate and meaningful fruit
descriptions and virtually impossible to identify them from the fruits
alone.
Fortunately,
however, the tree characteristics commonly exhibit greater differences
than do the fruits and hence are useful in both description and
identification. Thus, the Lisbon tree in California is
characterized by maximum growth vigor, thorniness, density of foliage,
size, cold resistance, and production of a crop mainly in winter and
spring. By contrast the Eureka tree is considerably less
vigorous, virtually thornless, less densely foliated, much smaller,
markedly less cold-resistant, and less productive but more
everbearing. The bulk of the Eureka crop is produced in
spring and summer. The Eureka variety also has a marked
tendency to produce the fruit in terminal clusters (fig. 4-75). The
characteristics of the Villafranca tree are intermediate between these
two extremes though somewhat closer to Lisbon. In California,
therefore, where the clones presently employed virtually all trace back
to these three varieties, tree characteristics are much more important
in description and more useful in identification than fruit characters.
All of those fruits that may be considered true lemons fall into two
natural groups: the common or acid lemons and the sweet or low-acid
lemons. Both groups are characterized by purple coloration in
the flower buds, new shoot growth, and chalazal spots.
Pink-fleshed bud sports are known to have occurred in the acid lemon
group, but the writer has been unable to discover any that have been
named and propagated commercially.
While some authorities would include the distinctive limettas of
the Mediterranean, in the opinion of the writer these can best be
regarded as a separate, closely related group and considered under C. limetta Risso.
Major Acid Lemon Varieties.—The following varieties represent the acid lemons which the author considers of primary importance.
Allen
See under Eureka.
Berna (Verna, Bernia, Vernia) (fig. 4-76)
Fruit medium in size, oval to broad-elliptical; neck or collar short;
nipple well developed. Seed content variable, but usually few
to none. Color bright yellow at maturity. Rind
medium-thick (thinner in summer crop); surface somewhat pebbled, rough;
tightly adherent. Crop comes mainly in winter but holds well
into summer, with undesirably large fruit, however.
Tree very vigorous, upright-spreading, large, and productive.
According to Gonzalez-Sicilia (1963) Berna is by far the most important
Spanish variety, constituting more than 90 per cent of the acreage in
the Levant. It is grown also in Algeria and
Morocco. In California, both the fruit and tree are much like
the Lisbon.
Bradbury
See under Lisbon.
Cascade
See under Eureka.
Cavers
See under Lisbon.
Comune
See under Femminello Ovale.
Cook
See under Eureka.
Corona Foothill Eureka
See under Villafranca.
Deaver
See under Lisbon.
Eureka (fig. 4-75 and 4-77)
Fruit medium-small, elliptical to oblong, sometimes obovate; commonly
with short neck or low collar at base; usually short but sometimes long
apical mammilla or nipple; frequently surrounded with areolar
furrow. Seed content variable but usually few to
none. Color yellow at maturity. Rind medium-thick;
surface finely pitted with sunken oil glands, slightly rugose, commonly
with low longitudinal ridges; tightly adherent. Segments
about 10; axis small and usually solid. Flesh color
greenish-yellow; fine-grained, tender, juicy; flavor highly
acid. Crop well distributed throughout year, but mainly in
late winter, spring, and early summer.
Tree medium in vigor and size, spreading and open in growth habit,
virtually thornless; sparsely foliated (in comparison with Lisbon and
others); strongly everbearing and produces fruit at the ends of long
branches (fig. 4-75);
precocious; productive. Tree lacking vigor compared with
most other varieties; more sensitive to cold, insect infestation, and
neglect; shorter-lived.
The fruit of
the Eureka variety differs in general from that of Lisbon, the principal
other variety in California, in that it is more prominently ridged and
has a somewhat rougher rind surface and usually a smaller and less
pronounced nipple. The tree differences are much more
marked. In addition to those differences mentioned earlier, the leaves are darker in color and less sharply pointed and the margins are somewhat more crenate than the Lisbon.
The Eureka variety originated in Los Angeles, California, in a group of
seedlings grown from fruit of Italian origin—the seed of which is said
to have been planted in 1858. Several years later Andrew
Boyle and C. R. Workman acquired some of these seedlings and eventually
they selected several that appeared to be promising. About
1877, Workman provided Thomas A. Garey, a prominent Los Angeles
nurseryman, with budwood from one of these seedlings and he propagated
and introduced it under the name of Garey's Eureka (Butterfield,
1963). Because of its precocity, thornlessness, and
everbearing nature, it soon rivaled the Lisbon variety. Both
have remained the principal varieties in California and have achieved
the status of major lemon varieties of the world. Eureka
ranks as a major variety in most important lemon-growing countries
except Italy, Spain, and a few other Mediterranean
areas. Russo (1955), as a result of a study of varieties in
California, recently expressed the opinion that Eureka has its ancestry
in the Lunario variety of Italy.
California nurserymen agree that the following clonal selections are
currently the most popular: Allen, Cascade, Cook, Meek, Ross, and
Wheatley or Thornton. Within the limits of normal variation
associated with environmental and disease factors, bud progenies from
the parent trees of these selections are virtually indistinguishable
with the exception of Ross, which is more
vigorous than typical Eureka and differs in other
respects. It is probably best regarded as a separate variety
of unknown origin.
Presumably because
of their greater vigor, caused in part at least by freedom from virus
infection, the use of known or presumed nucellar clonal budlines during
recent years has increased to the extent that virtually all Eureka lemon
trees propagated in California are now seedling or nucellar clonal
selections. The only known nucellar line in use is
Frost, originated by the geneticist and breeder, H. B. Frost, at the
Citrus Research Center, Riverside, California. What are
presumed to be nucellar lines of some of the most popular clonal
selections—Allen, Cook, Cascade, etc.—are now in use and others will
soon become available.
Femminello Ovale (Comune, Ruvittaru)
Fruit of medium size, short elliptical; rounded at base or very faintly
necked; nipple low and blunt (much less prominent than in Sfusato);
seeds comparatively few and mostly rudimentary. Color yellow
at maturity. Rind medium-thick; surface finely pitted with
depressed oil glands, moderately smooth; tightly
adherent. Segments about 10; axis of medium size and
solid. Flesh tender, juicy, and very highly
acid. Crop well distributed throughout year but mostly in
late winter and spring.
Tree of
medium vigor and size, nearly thornless; leaves medium-sized; highly
productive. Especially well adapted to the forcing treatment.
The oldest and still most important
Italian lemon varieties belong to the Femminello group, which according
to Burke (1962) accounts for approximately three-fourths of Italian
production. The Femminello varieties are characterized by a
pronounced everblooming, everbearing habit which makes them especially
responsive to the forcing or verdelli treatment so distinctive of
Sicilian lemon culture. The fruit is of good quality,
suitable for both shipment fresh and processing, and the trees are
moderately to highly vigorous, upright-spreading, and
productive. Unfortunately, with few exceptions, varieties of
this group are susceptible to the mal secco disease. The two
most important varieties of this group are the older Sfusato (see below)
and the newer Ovale or Comune.
Because of its regular and abundant production, good shipping and
storage quality, and adaptation to the verdelli treatment,
Femminello Ovale has long been the principal Italian
variety. Unfortunately it is very susceptible to the mal
secco disease. The comparatively new Santa Teresa variety, which is somewhat similar to Ovale and thought to be a derivative of it, is said to have resistance to this disease.
Femminello Sfusato (Favazzina, Siracusa)
Fruit of medium size, elliptical to oblong; prominently necked and with
large long-tapering nipple; seedy. Color yellow at
maturity. Rind medium-thick; surface finely pitted with
sunken oil glands, medium smooth; tightly adherent. Segments
about 10; axis of medium size and semi-open. Flesh firm,
juicy, and highly acid. Crop well distributed throughout year
but mainly in late winter and spring.
Tree very vigorous, upright-spreading, large, spiny; leaves large;
highly productive. Especially well adapted to the forcing
treatment.
Russo (1955) is of the
opinion that the California Lisbon clones are remarkably similar to or
identical with the Italian Femminello Sfusato. Once highly
important in Italy, this variety has largely been replaced by Femminello
Ovale and others.
Fino
See under Mesero.
Frost Eureka
See under Eureka.
Gallego
See under Lisbon.
Galligan
See under Lisbon.
Hall
See under Lisbon.
Interdonato (Speciale)
Fruit large, oblong-cylindrical; collared or short-necked; truncate at
apex; prominent sharp-pointed conical nipple surrounded by pronounced
areolar furrow, commonly deeper on one side; seeds very
few. Color yellow at maturity. Rind thin, very
smooth, shining; tightly adherent. Segments 8 to 9; axis
medium-small and solid. Flesh color greenish-yellow; crisp
and juicy; flavor highly acid with slight bitterness. Crop
produced mainly in fall and early winter. Earliest of Italian
varieties.
Tree vigorous,
upright-spreading, usually thornless; foliage moderately
dense. Leaves large and somewhat citron-like, with
round-pointed blades, undulate margins, and short wingless
petioles. Moderately productive but does not respond well to
forcing treatment and hence grown primarily for early fruit.
According to Burke (1962), the very distinctive Interdonato variety,
which currently accounts for about 5 per cent of Italian production, has
been planted solely because of its resistance to mal secco disease, to
which its resistance is said to be intermediate between the Femminello
and Monachello varieties.
Interdonato
is considered a lemon-citron hybrid and is said to have originated
about 1875 on the property of a Colonel Interdonato in Nizza, Sicily.
Jameson
See under Lisbon.
Kaweah
See under Lisbon.
Ledig
See under Lisbon.
Limoneira 8A
See under Lisbon below.
Lisbon (fig. 4-78)
Fruit medium in size, elliptical to oblong; base tapering to
inconspicuous neck; apex tapering likewise into a usually large,
prominent nipple surrounded by an irregular areolar furrow, commonly
deeper on one side. Seed content variable, but usually few to
none. Color yellow at maturity. Rind
medium-thick; surface finely pitted, faintly rugose, inconspicuously
ribbed if at all; tightly adherent. Segments about 10; core
small and solid. Flesh color pale greenish-yellow;
fine-grained, tender, juicy; flavor very acid. Crop comes
mainly in winter and early spring.
Tree vigorous, upright-spreading, large, thorny, densely foliated, and
productive. Tree most vigorous of varieties grown in
California and most resistant to adverse conditions such as frost, heat,
wind, and neglect.
The Lisbon fruit
is generally smoother and less ribbed than Eureka, the nipple and
areolar furrow more prominent, and the taper at the ends more
gradual. The characters are so variable and overlapping,
however, as to make identification from small samples uncertain, if not
impossible. The tree is quite different from the Eureka, however, and easily distinguishable.
Lisbon is of Portuguese origin, although it is not known there by that
name. It is believed to be a selection of the Gallego
seedling clonal group, which in Portugal is somewhat comparable to the common sweet orange groups
of Spain, Italy, and numerous other countries. A selection
known as Portugal in Morocco and Algeria is said to be indistinguishable
from the Lisbon introduced from California.20
The earliest reference to Lisbon in California appears to be its
listing in the 1853 catalogue of Warren and Sons Nursery and Garden in
Sacramento. It was brought to California in 1849 or soon
thereafter from Massachusetts by J. L. L. F. Warren, who had listed it
in a nursery catalogue issued at Nonantum Vale, near Boston, as early as
1843 (Butterfield, 1963). It is virtually certain that this
variety ultimately reached southern California, for Caryl (1940) reports
that budwood from an old Lisbon lemon tree growing in Alameda was
shipped to S. P. Stowe of Goleta in 1883.
Two importations are known to have been made from Australia, where this
variety was introduced as early as 1824 (Bowman, 1955). The
first was by S. P. Stowe in 1874, who shared his introduction with
Thomas A. Garey, a pioneer citrus nurseryman of Los
Angeles. The second was by J. W. North of Riverside, who
received a few small trees in 1875 and turned them over to D. N.
Burnham, a California nurseryman.
The
vigor, hardiness, and high productivity of Lisbon combined to establish
its early and enduring popularity, particularly in the California
interior districts. Eureka has been its only rival,
principally in the coastal districts, though in recent decades that
variety has declined somewhat in popularity in favor of
Lisbon. Although not as widely grown as Eureka in most other
lemon-producing countries, Lisbon is unquestionably one of the major
varieties.
It early became evident
that in California this variety contained several clones which differed
in vigor, size and abundance of thorns, compactness of branching, and
denseness of foliage. Principal among these selected for
propagation were the so-called "short-thorn," "semidense," and "open"
types as well as the "standard" clone characterized
above. Since Lisbon is not regarded as a clonal variety in
its country of origin and at least three independent introductions
contributed to its propagation in California, the facts strongly support
the conclusion that these types or so-called "strains" were contained
in the original introductions and that, as a consequence, Lisbon should
properly be regarded as a group of clones in California, probably of
common parentage, rather than a single clonal variety. All of
the clones currently propagated seem to be of the standard or
short-thorn types, both of which are characterized by high vigor and
productivity.
In California, the
selection of outstanding trees for use in propagation has been widely
employed for some decades, which has made possible comparison of
numerous individual tree bud progenies. It is the consensus
of the nurserymen that the old budline clonal selections currently most
in demand are Galligan, Limoneira 8A, Monroe, Prior, Rosenberger, and
Strong, and to a lesser extent Kaweah and Walker. Selections
of importance in the recent past include Bradbury, Cavers, Deaver, Hall,
Jameson, Ledig, Price, Prospect, and USDA. At the time of
their selection, the bud parent trees were outstanding in vigor and
productivity and were considered to be typical for the variety.
With two possible exceptions—Galligan and Rosenberger—bud progenies are
indistinguishable within the normal range of variation produced by
environmental and disease factors. Since the Galligan orchard
was planted in 1886 with trees from Florida, which are said to have
been ordered as Villafranca, the probability exists that this selection
is of that variety. There is general agreement, however, that
Rosenberger differs appreciably from Lisbon in both fruit and tree
characters and also from Galligan to a somewhat lesser
degree. Since its bud parentage is uncertain, the writer
believes it is best to consider Rosenberger
a separate variety of unknown origin. In arriving at these
conclusions, he is aware that they will be strongly contested by some
authorities.21
Within recent decades, the use of seedling clonal lines has become
popular in California and is increasing. The only known
nucellar clonal budline of the Lisbon variety is Frost,
which was produced by the geneticist and breeder H. B. Frost at the
University of California Citrus Research Center,
Riverside. More recently, what are presumed to be nucellar
lines have been obtained from some of the named oldline clonal
selections. A few of these have been propagated and currently
are being planted.
Meek
See under Eureka
Mesero (Primofiori, Fino)
Fruit spherical to oval; nipple comparatively small and sharp-pointed;
moderately seedy. Paler in color than Berna and rind smoother and thinner. Also higher in juice and acid content. Crop comes mainly in winter.
Tree exceptionally vigorous, attaining large size, very thorny, and
highly productive. Foliage density and leaf size greater than
Berna.
This variety, of unknown
Spanish origin, is said to be preferred by processors, but is much less
extensively grown than Berna. It should not be confused with
the Primofiore of Italy which refers to fruit produced from the first or
spring bloom.
Monachello (Moscatello)
Fruit medium-small, elliptical but tapering at both ends; neck lacking;
nipple small and inconspicuous; seeds few or none. Color
yellow at maturity. Rind thin; surface smooth but with large
sunken oil glands; very tightly adherent. Segments about 10;
axis medium-small and solid. Flesh tender, somewhat lacking
in juice, and acid content lower than most. Crop well
distributed throughout year but mainly in winter and spring.
Tree somewhat lacking in vigor, slow growing, and round-topped;
strongly drooping, slender, nearly thornless branches; dense
foliage. Leaves large, thick, with undulate margins, and
brighter green than most lemons. Fruit produced inside the
foliage canopy. Moderately productive in comparison with
Femminello and well adapted to forcing but with markedly reduced winter
crop.
The outstanding virtue of this
distinctive Italian variety is its resistance to mal secco
disease. This is the reason for its extensive planting some
decades ago to the point where it was second only to
Femminello. In all other respects, it is inferior to
Femminello and currently it is planted only in areas where mal secco is
very severe.
Certain characteristics
of this variety, particularly the distinctive growth habit and
cross-sectional shape of the larger branches, suggest that it is a
lemon-citron hybrid.
Monroe
See under Lisbon.
Moscatello
See under Monachello.
Portugal
See under Lisbon.
Price
See under Lisbon.
Primofiori
See under Mesero.
Prior
See under Lisbon.
Prospect
See under Lisbon.
Ruvittaru
See under Femminello Ovale.
Siracusa
See under Femminello Sfusato.
Speciale
See under Interdonato.
Strong
See under Lisbon.
Thornton
See under Eureka.
USDA
See under Lisbon.
Verna
See under Berna.
Vernia
See under Berna.
Villafranca
Fruit indistinguishable from Eureka, but seasonal distribution of crop
more like Lisbon, mainly in winter.
Tree similar to Lisbon, but more open and less upright in growth habit,
less thorny, and not as densely foliated.
These characterizations are adapted from Webber (1943), since the
original clone has been little propagated commercially in California, or
elsewhere so far as can be ascertained, for many of
decades. Indeed, Villafranca is currently of so little
importance as scarcely to warrant inclusion here. The only
reason for including it lies in the fact that certain clones with
characteristics intermediate between Eureka and Lisbon have been
propagated as selections of those varieties. Almost certainly
several of those currently of importance in California—notably the
so-called Galligan Lisbon and Corona Foothill Eureka selections—are in
reality Villafranca selections. This may conceivably be true
also of the popular so-called Rosenberger Lisbon and Ross Eureka
selections.
Said to be of Sicilian
origin, the Villafranca variety was introduced into Florida by H. S.
Sanford about 1875 and brought to California not long thereafter.
Wheatley
See under Eureka.
Minor Acid Lemon Varieties.—Acid
lemon varieties of local importance or which possess distinctive
characteristics suggesting promise for the future are presented below.
Amalfitana
See under Lunario.
Arancino (Cucuzzaru)
Arancino is one of a number of minor Italian varieties listed by Casella (1935a). The
highly distinctive fruit is nearly globose, with a very short nipple
and thick rind, and very seedy. The tree is vigorous, hardy,
and compact, with small spines and leaves. Arancino is very
responsive to the forcing treatment under which the fruit occurs in
clusters.
Armstrong (Armstrong Seedless)
Both tree and fruit of this California variety are much like the
Eureka, but Armstrong is more vigorous and less productive and the
latter is less seedy (only occasionally a seed). The budded
parent tree came to notice about 1915 in the orchard of Sanford Johnson,
Riverside, and is thought to represent an unwittingly propagated bud
variation of Eureka. It was called to the attention of A. D.
Shamel of the U.S. Department of Agriculture in 1936 and was patented in
1939 (U.S. Patent No. 342) and introduced by the Armstrong Nurseries of
Ontario. Recommended as a home garden variety, it has not
achieved much importance.
Asaasli (Saasli, Sakosli)
Asaasli is a vigorous, productive variety of Lebanon and
Syria. It is said to have originated on the Island of Chios
(Greece). The tree resembles Lisbon and the fruit is somewhat
like Eureka, but the crop occurs mainly in late winter and spring.
Assam
See under Nepali Oblong.
Bonnie Brae
Fruit medium-large, oblong to long elliptical-shaped; both neck and
nipple usually lacking; moderately seedy. Rind very thin,
smooth, and leathery. Flesh crisp and somewhat lacking in
juice and acid. Tree lacking in vigor and frost-sensitive.
This California variety originated as a seedling from seed of Italian
origin grown by H. M. Higgins near San Diego, who named and introduced
it about 1880. Although the fruit is highly attractive, it
proved to be unsuitable for commercial culture. This variety
is now merely a collection item.
Corpaci
Corpaci is a local Italian variety of interest only in the Simeni area
near Siracusa. The fruit has both a well-developed neck and
nipple, is low in seed content, and matures earlier than most other
varieties. The tree is vigorous, thorny, and productive.
Cucuzzaru
See under Arancino.
Frost Lisbon
Frost is at present the only known
nucellar selection of Lisbon available. It was derived in
1917 by H. B. Frost of the Citrus Research Station, Riverside, and was
released about 1950. Seedling budlines presumed to be of
nucellar origin have recently been derived from some of the most popular
California clonal selections, however, and currently are being planted
to some extent.
Genoa (Genova)
Genoa is a California variety which Webber (1943) says is of the Eureka
type and difficult to distinguish from it. As the writer saw
it in Chile, where it was taken from California and constitutes the
principal variety, it appeared to be somewhat more vigorous, densely
foliated, and cold-resistant. It was introduced into
California about 1875 from Genoa, Italy, by Jose Rubio of Los
Angeles. So far as the writer has been able to ascertain, it
has achieved commercial importance only in Argentina and Chile.
Genova
See under Genoa above.
Kusner
Kusner is a vigorous, productive Russian variety said to have
originated from the breeding program of the government research station
at Sukhum, Georgia. In California, it is indistinguishable
from Lisbon or the Vernia introduced from Morocco.
Lambert Eureka
This Australian chance seedling is indistinguishable from Eureka except
that it is more vigorous and productive and hence is believed to be of
nucellar origin. Lambert was found by R. J. Benton, former
government citrus specialist, about 1940 on the place of Horace Lambert,
Moorland, New South Wales. It is said to be highly promising
as a replacement for old clonal selections.
Lo Porto
The fruit of this new Italian variety is characterized by a globose
form and a very large, fleshy calyx. Lo Porto was found in
Altarello di Baida, a village in the Conco d'Oro district of Sicily,
during the course of a mal secco resistance survey. It was
first described by Crescimanno (1953), and is said to have considerable
resistance.
Lunario (Amalfitano, Quatre Saisons) (fig. 4-79)
Fruit medium-large, long elliptical to long-obovate; commonly with
well-developed neck or furrowed collar; usually with narrow
sharp-pointed nipple; seedy. Rind smooth and
medium-thin. Flesh color greenish-yellow; not very juicy;
only moderately acid. Tree of medium vigor and size, strongly
overbearing, thornless; foliage dark green; highly productive.
Lunario is a distinctive Italian variety. It is very
responsive to the forcing treatment but the verdelli fruit is smaller in size, and the following winter crop is markedly reduced in amount.
Lunario is of local importance in parts of Sicily and the Amalfi area
near Naples and is grown to some extent in Libya, Tunisia, and Algeria.
Malti
This is a Lebanese variety of unknown origin. The tree is
moderately vigorous, thorny, and productive, and the fruit resembles the
Lisbon. The crop comes mainly in fall and
winter. The Malta lemon of northern India is probably the
same variety.
Nepali Oblong (Assam, Pat Nebu or Nimbu)
Fruit medium large, long elliptic to oblong-obovate; base rounded;
nipple broad but low. Rind medium-thick, firm; surface very
smooth, shining; clor greenish-yellow. Segments about 11 and
axis hollow. Flesh color greenish-yellow; fine-textured,
juicy; not very acid. Seeds few to none.
Tree vigorous, spreading with flat and open crown of drooping, nearly
spineless branches; foliage citron-like. Everbearing.
Nepali Oblong is the principal native so-called lemon of India and is
said to have originated in Assam (Bhattachariya and Dutta,
1956). Both tree and fruit exhibit numerous citron
characters.
Pat Nebu or Nimbu
See under Nepali Oblong above.
Quatre Saisons
See under Lunario.
Real
This Spanish variety produces a very large, oblong, thick-rinded,
highly seedy fruit of low juice content and medium
acidity. It is locally important in the vicinity of Málaga.
Rosenberger
Rosenberger is a vigorous, highly productive clone that is currently
popular in California. While commonly considered to be of the
short-thorn Lisbon type, the fruit is shorter, plumper, and more
truncate at the base, and there are minor tree
differences. Rosenberger also differs somewhat, although less
so, from what is considered to be true Villafranca. As a
consequence and because of its importance, the writer considers it best
to give Rosenberger varietal standing. It traces back to an
old orchard owned by W. B. Cavers at Upland, which is said to have
consisted of both Lisbon and Villafranca trees. It was named
for the Rosenberger orchard of the same locality, where its outstanding
performance attracted attention.
Ross (Ross 10-1)
Ross is a vigorous, productive clone that has been popular in recent
decades in California. While commonly referred to as a
selection of Eureka, from which the fruit is indistinguishable, the tree
is more vigorous and densely foliated, and there are other minor
differences. Because of these differences and its current
importance, it seems best to give Ross varietal standing. The
parent tree was selected from a group of similar trees in an orchard
owned by W. G. Ross at Escondido and planted in 1913. The bud
parentage is unknown.
Saasli
See under Asaasli.
Sakosli
See under Asaasli.
Santa Teresa
This comparatively new Italian selection of the Femminello Ovale type
is considered to be highly promising because of its greater resistance
to the mal secco disease than any other clone found thus
far. The parent tree was an old disease-free tree discovered
in a Femminello orchard that had almost been destroyed by the disease
(Russo, 1955). It is said to be the variety currently most
planted as a replacement in areas of Italy where the disease is severe.
Ornamental Lemon Varieties.—Clones
which exhibit variegation in the leaves or fruit, or both, have
occurred as limb sports and some of the most stable of these have been
propagated for use as ornamentals. One of the best of these
ornamentals is the Variegated Prior Lisbon. Perhaps the most
interesting ornamental, however, is the variegated, pink-fleshed
lemon. At least two such clones have come to notice—one of
Eureka in California and another of unknown origin in the Mediterranean (Citron Sanguin Panaché).
Sweet Lemon Varieties.—The
writer is acquainted with only one named variety of the true sweet
lemon—Dorshapo—but has seen this same fruit in Tunisia under the name of
citron doux, where it is grown to some extent and much
appreciated by the Arab population. In Tunisia, it commands
higher prices than common lemons. Moreover, Chapot (1963d)
states that it occurs, although not commonly, in Morocco and Turkey and
doubtless elsewhere in the Mediterranean. He has reported
(1963d) the remarkable fact that this clone regularly produces a
few normally acid fruits and some in which the individual fruits contain
both acid and sweet juice sacs or vesicles. Chapot
postulates chimeral natures of the clone as the probable cause.
Webber (1943) placed the Millsweet limetta with the sweet lemons, but the writer has included that fruit with the other limettas. The pani-jamir of Assam (Bhatachariya and Dutta, 1956) appears to be a true sweet lemon.
Dorshapo
Fruit much like Eureka but slightly more ribbed; nipple somewhat more
prominent; areolar furrow commonly deeper on one side. Flesh
color amber-yellow; sweet, insipid, and lacking the typical flavor of
the sweet lime. Acidity very low but not completely lacking.
Tree much like Eureka, but more vigorous, thornier, and less
productive. Flower buds and young shoot growth purplish-red
tinted.
This variety was introduced
into the United States from Brazil in 1914 and was named for the
introducers—(Dor)sett, (Sha)mel and (Po)penoe of the U.S. Department of
Agriculture.
Fruits Resembling the Lemon.—Some
of the lemon varieties, as previously noted, exhibit characteristics of
citron to a certain degree. This appears true of Monachello,
Interdonato and Francescano of Italy, San Jeronimo of Spain, and Nepali
Oblong and other lemons of India (Randhawa, Singh, and Choudhury
1960). Since the lemon characteristics are predominant and
such fruits are grown and marketed as lemons, these varieties were
included with the true lemons.
A lemon-like fruit in which characters of the sweet citron are evident is the peretta (C. peretta Risso). It
is large, ellipsoid in form, and with pronounced neck and prominent
nipple. The rind is thick and citron-like and the flavor
sweet and insipid. Peretta is an old variety of Italy and the
French Riviera. It is of minor importance and grown only in
dooryard plantings.
There are other
fruits, however, in which lemon characters are evident but the
differences are such as to warrant their separate
classification. Among the most important of these are jamberi or rough lemon, the karna, and the galgal or hill lemon of India, the Meyer lemon, and the limettas, which are discussed separately in the next subsection.
Alemow or Colo (C. macrophylla Wester) (fig. 4-80)
Fruit medium-large, oblong to obovate; often with prominent mammilla
surrounded by circular furrow; seedy. Rind medium-thick (for
size of fruit); surface somewhat rough and bumpy; tightly adherent;
color greenish-yellow. Segments numerous (about 15); central
axis large and solid. Flesh color greenish-yellow; low in
juice; strongly acid and bitter. Seeds polyembryonic.
Tree vigorous, spreading, very thorny (with short stout spines);
flowers and new growth strongly purple-tinted. Leaves small
to medium, pale green, narrow elliptical, blunt-pointed, and with
broadly winged petioles of the pummelo type.
Lemon or lime characters in the alemow are discernible, and there is
some suggestion of pummelo. The writer has provisionally
placed the alemow in this group, and it is included in this treatment
because of its promise as a lemon rootstock in California where the
soluble salt and boron content of the soils is unfavorably high for the
commonly used rootstocks. Alemow is said to be native to the
Island of Cebu, Philippine Islands.
Citronelle
See under Rough Lemon.
Colo
See under Alemow.
Estes
See under Rough Lemon.
Galgal or Gulgul (C. pseudolimoni Tan.) (fig. 4-81)
Fruit medium-large to large, oblong to ellipsoid; low, sometimes
furrowed collar or neck; usually with short blunt-pointed nipple,
sometimes depressed and flat. Rind medium-thick; surface
usually smooth but sometimes moderately rough; tightly adherent; color
pale to golden yellow. Segments about 10; axis large and
hollow. Flesh color pale yellow; coarse in texture,
moderately juicy; flavor very sour and with trace of
bitterness. Seeds numerous and large.
Tree vigorous, upright or spreading but irregular and open, with stout
branches, numerous thick spines; leaves large and dull-green, resembling
the sweet lime in form and tendency to rolling or
cupping. Flowers large, purple-tinged, and produced in spring
only. New shoot growth purple-tinted.
This Indian citrus fruit of ancient and unknown origin is also known as
the hill lemon or Kumaon lemon. While resemblances to the
lemon are obvious, there are notable differences, among which are the
essential oils and hence the aroma of both leaves and rind, and the
single bloom, one-crop behavior. Moreover, the tree is more
resistant to both cold and heat.
The
galgal has commercial importance only in submontane areas along the
Himalayas and in parts of the Punjab where it is grown as a substitute
for the lemon or lime. Several unnamed clones are propagated
commercially, including an acidless form.
Gulgul
See under Galgal above.
Jamberi
See under Rough Lemon.
Karna (Kharna Khatta, Karna Nimbu, Khatta Nimbu) [C. karna Raf.] (See fig. 4-82)
Fruit medium to medium large, of variable form but in general round to
oval; usually with broad and prominent nipple, sometimes depressed or
lacking. Rind moderately thick, firm; surface smooth, warty
or ribbed; tightly adherent; color golden yellow to deep
orange. Segments about 11; axis medium-large and semi-hollow
to solid. Flesh color dull orange; coarse-textured, only
moderately juicy; flavor acid with faint aroma suggestive of sour
orange. Seeds numerous, somewhat slimy, and moderately
polyembryonic.
Tree vigorous, medium
to large in size, upright-spreading, spiny; foliage lemon-like but
darker green. New growth purple-tinted. Flowers
medium-large and strongly purple-tinged. One bloom and crop
per year.
Karna is an old Indian
fruit of unknown origin, and almost certainly a natural
hybrid. While the tree and fruit are distinctive, they
exhibit characters of both rough lemon and sour or bitter orange, and
there are also characters suggestive of the acid citron. The
commercial importance of karna arises solely from the fact that it is
extensively employed in India as a rootstock, second only to rough
lemon.
Karna Khatta
See under Karna above.
Khatta Nimbu
See under Karna above.
Kumaon Lemon
See under Galgal.
Mazoe Lemon
See under Rough Lemon.
Meyer Lemon (C. meyeri Y. Tan.) (fig. 4-83)
Fruit medium in size, oblong to short elliptical, sometimes faintly
ribbed; base rounded, sometimes faintly necked and radially furrowed;
apex rounded or with low, broad nipple. Rind thin, soft;
surface very smooth; tightly adherent; color yellowish-orange to
orange. Segments about 10; axis small and
solid. Flesh color light orange-yellow; tender, very juicy;
lemon-flavored and acid. Moderately seedy. Crop
distributed somewhat throughout the year but mainly in winter.
Tree moderately vigorous, small to medium in size, spreading, nearly
thornless, hardy, and productive. Flowers and new shoot [sic] purple-tinted. More or less everflowering but mainly in spring.
The Meyer lemon compares favorably with the sweet orange for both cold
and heat resistance and thus has a much wider range of climatic
adaptation than either the common lemon or lime for which it is used as a
substitute. The fruit is remarkably affected by climatic
factors and differs greatly in appearance in different regions.
This fruit was found near Peking, China, by the plant explorer Frank N.
Meyer of the U.S. Department of Agriculture and introduced in
1908. Because of its obvious resemblances to the lemon and
its suitability as a substitute for that fruit, it has come to be known
as the Meyer lemon.
Introduced as a
promising ornamental, it rapidly increased in popularity and soon
fulfilled the most sanguine expectations. It has become one
of the most widely used citrus fruits as a dooryard plant and is
especially adapted for use potted or tubbed. Unfortunately,
however, its use is currently banned in some citrus areas because of the
hazard it is considered to present as a symptomless carrier of certain
viruses, particularly tristeza. Virus-free clones, several of
which are currently available, will doubtless replace those employed in
the past and thus preserve this useful and attractive ornamental.
Although acceptable as a lemon substitute for home use, the Meyer lemon
has not proven satisfactory as a commercial variety for the fresh-fruit
trade. The fruit is too tender and juicy to withstand
handling, shipping, and storage without excessive
waste. Moreover, it does not cure or color well during
storage, nor is it acceptable to most consumers when lemons are
available. As a consequence, it has failed to establish
itself as a commercial variety of more than local importance
anywhere. Meyer lemon was planted fairly extensively in
Texas, South Africa, and New Zealand, but appears to have declined in
favor since World War II. In Florida, however, some interest
has been shown in it as a possible lemon substitute for local markets
and for processing.
Milam
See under Rough Lemon below.
Rough Lemon (Jamberi, Jatti Khatti, Mazoe Lemon, Citronelle) [C. jambhiri Lush.] (fig. 4-84)
Fruit medium in size, of highly variable form but usually oblate to
elliptic-oblong; commonly with irregularly furrowed or lobed basal
collar or neck; usually with broad apical nipple surrounded by a deep
irregular areolar furrow. Rind medium-thick; surface
typically deeply pitted, and rough or bumpy, sometimes ribbed; easily
separable; color lemon-yellow to brownish-orange. Segments
about 10; axis large and hollow. Flesh color light yellow to
pale orange; medium juicy; flavor moderately acid. Seeds
numerous, small, highly polyembryonic, and cotyledons faintly
green. Some crop throughout the year but mainly in winter.
Tree vigorous and large, upright-spreading, with numerous small thorns;
leaves medium-small, blunt-pointed, and light green. Flowers
small and mandarin-like, purple-tinged, and produced more or less
throughout year, but mainly in spring and late summer. New
shoot growth faintly purple-tinted. Sensitivity to cold about
like that of true lemons.
This
species exhibits a remarkable range of variation in fruit characters,
and in India, where it is native, four relatively distinct types are
recognized, one of which is similar to the form obtained from Italy
known as C. volckameriana (for description see Chapot, 1965a). There is also a sweet-fleshed form.
Presumably native to northeastern India, where it still grows wild, the
rough lemon seems to have been taken to southeast Africa by the
Portuguese toward the end of the fifteenth or early sixteenth century
and thence to Europe. It doubtless reached the New World not
long thereafter.
Although used to
some extent as a lemon substitute, for which it is not very suitable,
the rough lemon is highly important as a rootstock in many parts of the
world—notably India, South Africa, Australia, Argentina, Brazil, and
Florida. In the last two mentioned countries, selections have
recently been named—Estes and Milam—which exhibit resistance to the
burrowing nematode.
While
resemblances to the lemon are fairly obvious, the differences are
greater, and many of its characters are clearly those of the Rangpur or
mandarin.
The Limettas (C. limetta Risso).—There
are three remarkably similar and evidently closely related lemon-like
fruits which, in the opinion of the writer, constitute a natural group,
probably best designated as the limettas—namely, the Millsweet so-called
sweet lemon, the Mediterranean or Tunisian (to distinguish it from the
Indian or Palestinian) sweet lime and the Moroccan limetta or Marrakech
limonette. The last fruit is comparatively little known and
not until recently has an adequate description become available (Chapot,
1962a). All three fruits are obviously closely
related to the lemon but exhibit differences in common that indicate
close interrelationship and common ancestry.
Within the range of normal variation, the trees are indistinguishable
except that the Mediterranean sweet lime does not exhibit pink
coloration in the flower-buds, flowers, and young shoot
growth. Moreover, the fruits do not exhibit significant external differences. Internally,
however, the following important differences are noted: Mediterranean
sweet lime (limetta)—flesh acidless, chalazal spot cream-colored;
Millsweet sweet lemon (limetta)—flesh low in acid, chalazal spot purple;
Moroccan limetta—flesh highly acid, chalazal spot purple.
Differences from the lemon, which set all three limettas apart as a
group, include a characteristic oval-shaped, round-pointed, and usually
somewhat cupped leaf, a highly distinctive fruit form, and an altogether
different rind oil closely resembling that of the bergamot.
In the writer's opinion, the limettas constitute a well defined group
of which the Moroccan limetta (Marrakech limonette) may be considered to
represent the normal acid form, the Millsweet limetta a low acid form
(comparable to Dorshapo lemon), and the Mediterranean sweet limetta the
acidless form.
Marrakech Limonette (Moroccan Limetta, Limoun Boussera)
Fruit medium-sized, depressed subglobose, commonly ribbed; base rounded
or somewhat flattened; apex strongly flattened with broad and deep
areolar furrow surrounding a prominent nipple. Rind thin,
moderately pitted with sunken oil glands; somewhat bumpy; adherent;
color light yellowish-orange. Segments about 11; axis medium
in size and open. Flesh color pale yellow; juicy; very sour
and aromatic. Moderately seedy, moderately polyembryonic, and
chalazal spot purple.
Tree vigorous,
large, upright-spreading and open, lightly spiny, and highly productive;
leaves lemon-like, but more oval, less sharp-pointed, and usually
somewhat cupped at upper end. Flowers purple in the bud and
new growth purple-tinted. Flowers somewhat throughout the
year but mainly in spring.
According to Chapot (1969a),
this fruit is confined to Morocco, where presumably it is native, and
was first described by Guillaumin (1921). It has little
economic importance and is used mainly as an ornamental though also as a
lemon substitute.
Mediterranean Sweet Limetta (Limetta de Tunisie, Limoncello, Arancio di Spagna)
Fruit indistinguishable from Millsweet limetta except acidless, hence
even more insipidly sweet; chalazal spot cream-colored instead of
purple.
Tree likewise
indistinguishable except flowers not purple-tinged and young shoot
growth not purple-tinted. Flowers white and shoot growth
green.
The Mediterranean sweet
limetta is an old and reasonably well-known fruit in the Mediterranean
and has considerable importance in Tunisia and some localities in
Italy. In view of the few and minor differences between these
two fruits, the confusion in the literature and otherwise is readily
understandable but nevertheless unfortunate. In addition,
this fruit has often been confused with the Indian or Palestine sweet lime which it resembles only slightly.
Millsweet Limetta (fig. 4-85)
Fruit virtually indistinguishable from Marrakech limonette except low
in acidity and hence tastes sweet and may average somewhat smaller.
Tree likewise indistinguishable, but perhaps somewhat less vigorous.
This is an old, comparatively little-known fruit in the Mediterranean,
but it must have originated there for it was early brought to
California, presumably from Mexico. Lelong (1888) quotes
General Vallejo as remembering having eaten the "sweet lemon" at
Monterey in 1822 and having seen trees of it that same year growing at
the San Gabriel Mission. Webber named it Millsweet and
described it as a sweet lemon variety in 1943.
The group name for the limes is lime in English and French and lima
in Italian and Spanish. In Arabic-speaking countries and the
Orient, the limes and lemons are generally grouped together under the
term limûn (limoon, limoun) for the former and nimbu or limbu (numerous modifications) for the latter.
Like the citron and lemon, the limes are believed to have originated in
northeastern India, adjoining portions of Burma, or northern Malaysia
and to have followed the same general path westward to the Mediterranean
basin and thence to the Western Hemisphere. Because of their
grouping with the other acid citrus fruits, however, it is difficult,
if not impossible, accurately to trace and time their westward
distribution (see chap. 1, this work). It
is virtually certain that the sour lime was among the fruits taken by
the Arabs across North Africa into Spain and Portugal and highly
probable that it was also taken to Italy by the Crusaders, although it
seems not to have persisted long in Europe. It is known to
have been brought to the Americas by the Spanish and Portuguese
explorers in the early part of the sixteenth century, where it escaped
from cultivation and became feral in parts of the West Indies, some
Caribbean countries, and southern Florida.
While exhibiting certain basic similarities, the true limes constitute a
highly varied group of which the members differ so significantly that
separate species standing appears to be justified. They fall
into two natural groups, however, the acid or sour limes and the
acidless or sweet limes. The acid limes include small-fruited
and large-fruited kinds and varieties.
While similarities exist between the small-fruited and large-fruited
acid limes, the differences are much greater. Moreover, there
are marked differences in climatic tolerances and reactions as well as
in resistance or susceptibility to certain diseases. Their
separation into different species seems therefore justified.
The tree differences are notable. Thus, the West Indian lime
is less vigorous and robust than the Tahiti, much finer-stemmed, very
much thornier, and has much smaller leaves of a distinctly paler
color. It is much more cold-sensitive (about like the citron)
and requires more heat to develop good fruit size. In
contrast with the Tahiti lime, it is highly susceptible to the withertip
fungus (Gloeosporium limetticolum), citrus canker (Xanthomonas citri), and
the tristeza virus, for which it is currently the most widely used
indicator plant. It is markedly resistant to the citrus scab
fungus (Elsinoë fawcetti).
The fruit differences are less marked, but in addition to the larger
size of fruit the Tahiti group is virtually or entirely seedless, and
the odor, while similar, is less pronounced. The flavor,
though about equally acid, lacks the strong pungency and aroma of the
West Indian lime.
Except in the
United States, the commercial lime industry is restricted to the West
Indian group, which is markedly cold-sensitive and has a high total heat
requirement for the production of fruit of good
size. Consequently, the lime industry has developed
principally in hot semitropical, subtropical, or tropical
regions. Indeed, this fruit is without a doubt the most
tropical of the commercially important citrus fruits. When
grown in cooler regions, such as southern California, the West Indian
lime is undesirably small and is discounted in the
markets. It has also been observed that the climates most
favorable for this lime are likely to be poorly suited to lemon culture
and that where good limes are available they are generally preferred to
lemons. These facts are believed to explain why the major
lime-producing countries and regions are India, Mexico, Egypt, and the
West Indies. Although statistics are not available, almost
certainly India is the largest center of lime culture. Lime
growing is widespread in the central and southern portions of that
country, and the fruit is used extensively. The 1965 crops
for Mexico and Egypt were reported at approximately 3.1 and 1.4 million
boxes, respectively, and production for the West Indies was estimated at
400,000 boxes. World production in 1967 was doubtless in the
range of 8 to 10 million boxes. A considerable part of the
Mexican crop is exported to the United States to supplement the Tahiti
limes grown in Florida and California.
Although it is known that the West Indian lime was planted on some of
the Florida Keys (reef islands off the southeast coast) as early as 1838
and that ultimately it became naturalized there (hence the term Key
lime), it was not until the early part of the present century that a
small commercial industry was developed in Florida. It was
short-lived, however, and suffered a reverse from the disastrous
hurricane of 1926, from which it never recovered. Early
introduced into southern California by the Spanish mission fathers,
attempts at its commercial culture invariably resulted in failure and
were abandoned many years ago.
Unusual or distinctive practices employed in the culture of this fruit
include the almost universal use of seedlings rather than budded trees
and a forcing treatment for the production of summer fruit in the Faiyûm
oasis, a major center of lime production in Egypt. It is
similar to the verdelli treatment employed in Sicily to increase the summer lemon crop.
Of all the citrus fruits, the West Indian lime is highest in percentage
composition for acid in the juice, ranging from 7 to 8 per cent
(calculated as citric). It is somewhat lower than the lemon
in ascorbic acid, however, and in other vitamins and hence has somewhat
less dietetic value. For many years, however, sour lime juice
(probably sweet lime also) was used in the treatment or prevention of
scurvy.
Much the greater part of the
crop is marketed and consumed fresh, its uses being similar to those of
the lemon. It is especially esteemed for the making of
limeade and carbonated beverages and as a constituent of and garnish for
alcoholic drinks. In the Orient, it is extensively used for
pickling and in culinary and medicinal preparations. In the
West Indies and to some extent elsewhere, a considerable part of the
crop has been used in the manufacture of bottled lime juice, which is
highly prized as a constituent of mixed alcoholic drinks. The
principal byproduct is lime oil.
Commercial culture of the Tahiti or Persian lime is much more recent and
less important and currently is confined to the United States where,
because of its cold-hardiness and lower heat requirement, it is much
better adapted than the better known and generally preferred West Indian
lime (fig. 4-86). Since
the limes succeed much better than the lemon in humid climates the
industry is almost entirely confined to Southern Florida, where its
comparatively low heat requirement causes this fruit to attain
acceptable maturity during the summer months—the period of greatest
market demand and best prices for the acid citrus
fruits. California does not possess this advantage because of
a much later season of maturity. In Florida, the Persian
lime is therefore a rather acceptable substitute for the preferred
Mexican lime. Because it approaches the lemon in size, it was
early found necessary to educate the markets to accept this fruit as a
true lime rather than a small lemon, but this prejudice seems now
largely to have been overcome. The 1965 Florida crop of
approximately 560,000 boxes was reported to have been produced from
3,500 bearing acres. There were about 500 acres in California
in 1965. A considerable part of the Florida crop of Persian
limes is processed into frozen concentrate limeade and lime
juice. Lime oil is a by-product.
The fruit-handling practices are much like those employed for
lemons. The fruit is picked to size and hence being largely
immature must undergo some storage and curing prior to packing and
shipping.
Small-fruited Acid Limes (Citrus aurantifolia
Swing.).—A species description of the small-fruited acid limes would
correspond in general to that given below under West Indian
lime. However, several types of this fruit are recognized in
India which differ in size, form, and degree of
seediness. Spineless forms also occur in India, have been
found in the Mediterranean, and are reported elsewhere. The
most interesting of these forms to the writer is the large-fruited,
long-elliptical form known as Abhayapuri Kaghzi, which is grown
commercially in Assam (Bhattacharya and Dutta, 1956) and adjoining
portions of West Bengal and East Pakistan and found in the markets of
Calcutta. So far as can be ascertained, however, only the
form described below has attained commercial importance elsewhere.
West Indian (Mexican, Key) (fig. 4-87)
Fruit very small, round, obovate or short-elliptical; base usually
rounded but sometimes with slight neck; apex also rounded but usually
with small, low, and faintly furrowed nipple. Moderately
seedy and highly polyembryonic. Rind very thin; surface
smooth, leathery; tightly adherent; color greenish-yellow at maturity, following which it drops from the tree. Segments
10 to 12; axis very small and usually solid. Flesh color
greenish-yellow; fine-grained, tender, juicy; highly acid with
distinctive aroma. Somewhat everbearing but crop comes mainly
in winter (earlier in very hot climates).
Tree medium in vigor and size, spreading and bushy with numerous,
slender, willowy fine-stemmed branchlets densely armed with small,
slender spines. Foliage dense and consists of small, pale
green, broadly lanceolate, blunt-pointed leaves with definitely winged
petioles. Flower buds and flowers small, and flowering occurs
throughout year but mainly in spring and late summer. Not
withstanding contrary statements in the literature, the new shoot growth
is faintly purple-tinted and flower buds and young flowers faintly
purple-tinged. Coloration fades rapidly, however, especially
if the weather is warm, and is soon lost. Very sensitive to
cold.
The West Indian or Mexican lime is the kaghzi nimbu (numerous modifications and other local names) of India, the limûn baladi of Egypt, the doc of Morocco, the Gallego lime of Brazil, and limon corriente in some Latin American counties. In North America, it is sometimes also called the Key lime.
Because of the relatively high degree of polyembryony exhibited by this
fruit, it comes remarkably true to seed, and seed propagation is still
employed in most of the countries where its culture is important—India,
Egypt, and Mexico. As a consequence, clonal varieties have
not been selected and named, except for a few which are noted
below. In this connection, it is significant to note that in
California it has been found impossible to distinguish between seedling
clones of the common acid lime from India, Egypt, and Mexico, and clones
of Florida and West Indian from origin budded trees. It
seems likely, therefore, that the principal clones employed are
genetically identical and that only one horticultural variety is
involved, which in California is known as Mexican and in Florida as West Indian or Key.
A nucellar seedling selection arising from the Mexican lime-grapefruit
cross was described and named Everglade in 1905 by Webber (1943) in the
belief that it produced a larger fruit. In California, it has
been indistinguishable from the parent clones and therefore has not
come into use. Thornless clones reported in the literature
include: Doc Sans Epines (Doc Thornless) of Morocco; Yung, a form
introduced into California from Morroco by George Yung about 1882 and
described and named by Webber (1943); an introduction from Trinidad
(West Indies) received by the United States Department of Agriculture in
1910, a limb sport which was found in the Ballard orchard near Weslaco,
Texas, shortly after the freeze of 1925; and a selection recently made
at Yuma, Arizona, by J. Hamilton of the U.S. Department of
Agriculture. None has proved to have commercial value.
Because they produce distinctive symptoms when infested with the
tristeza virus, West Indian lime seedlings are widely used as an
indicator in the detection of this disease.
Large-fruited Acid Limes (Citrus latifolia Tan.)—The two most important large-fruited acid limes are the Tahiti and the Bearss, which are described below.
Tahiti (Persian)
Fruit medium-small (like small lemon), oval, obovate, oblong or
short-elliptical; base usually rounded but sometimes slight necked and
faintly furrowed; apex rounded; areolar area elevated into a low
nipple. Seeds are or lacking. Rind thin; surface
smooth, tightly adherent; color pale lemon-yellow at
maturity. Segments about 10; axis small and usually
solid. Flesh color pale greenish-yellow; tender, juicy; very
acid and with true lime flavor. Somewhat everbearing, mainly
in winter (earlier in hot climates such as southern
Florida). If left on tree past maturity, some fruits develop a
peculiar breakdown in the areolar area at the stylar end.
Tree vigorous, broad-spreading, drooping, medium to medium-large,
nearly thornless; foliage dense green. Leaves medium in size,
broadly lanceolate, and petioles winged. Flower buds and
flowers medium in size and flowering occurs throughout year, mainly in
spring. Purple coloration usually faint and evanescent in
both flowers and shoots. Fully as cold-resistant as the true
lemons.
The origin of the Tahiti or
Persian lime is unknown, and its history is obscure. The name
Tahiti arises from the fact that this type of lime was introduced in
California from Tahiti sometime during the period of 1850 to
1880. As the Persian lime, it was introduced into Australia
as early as 1824 (Bowman, 1955), possibly from Brazil, since it is
mentioned in connection with the Celeta (Seleta) and Bahia orange
varieties of that country. The origin of the name Persian is
unknown, however, although it seems likely that this fruit came to the
Mediterranean area via Persia as did the citron. Currently,
it is not to be found in Persia, however (Chapot, 1965b). The Sakhesli lime
of the island of Djerba (Tunisia) is clearly of the same type and has
been grown there for a long time, presumably centuries. H.
Chapot, the distinguished French citrus systematist, reports that he has
also seen old trees of this fruit in Algeria and that the name Sakhesli
means "from Sakhos," an Arabic name for the island of Chios (Greece).22
While the only commercial variety of the Tahiti lime apparently
produces no viable pollen and is normally seedless, Reece and Childs
(1962) succeeded in obtaining 250 seeds from a commercial canning plant
in Florida from which 140 seedlings were planted in an orchard and 77
survived and ultimately fruited. A high degree of monoembryony is
indicated as only two seedlings proved to be indistinguishable from the
parent clone. The remaining seedlings exhibited a very wide
range in species characters, but approximately 60 per cent were
predominantly citron, lemon, or seedy acid lime. From these
data, Reece and Childs concluded that this lime is clearly of hybrid
origin, that one parent is obviously the common acid lime, and that the
other is either lemon or citron, but probably the latter. It
is interesting that they were unable to observe more than 18
chromosomes, the normal diploid number for the genus, whereas Bacchi
(1940) reported this lime as triploid in genetic constitution.
While further study will be required to make certain of the facts, it
appears that there are presently several horticultural clones of Tahiti
or Persian lime, only one of which is commercially important.
Bearss (Bearss Seedless, Persian) (fig. 4-88)
Both tree and fruit of the Bearss variety correspond closely with the
Tahiti description. The flowers are devoid of viable pollen
also, contain exceedingly few functional ovules, and the fruits are
regularly seedless. The Bearss variety is triploid in its
genetic constitution (Bacchi, 1940). Moreover, the
comparatively rare seeds which occur are highly monoembryonic also.
According to Webber (1943), this variety originated about 1895 on the
place of T. J. Bearss, a nurseryman at Porterville,
California. While the facts are unknown, it presumably
occurred as a seedling of a tree grown from seed from a fruit of
Tahitian origin. It seems first to have been described and
illustrated by Lelong (1902) and was introduced and promoted by the
Fancher Creek Nursery Company of Fresno in 1905. Although the
Tahiti lime was reported to be growing in Florida as early as 1883
(Ziegler and Wolfe, 1961), it is not known when Bearss was introduced
there. Moreover, the present lime industry in Florida is
based on a variety known as Persian. For many years,
therefore, it appeared that the two varieties were different though
obviously similar. Comparisons conducted in California,
however, although not wholly satisfactory because of complicating
disease factors, strongly support the conclusion that the two clones are
identical. If this is indeed the case, it seems highly
probable that this variety originated considerably earlier than Webber
reports.
Found about 1934 by G. L.
Polk in Homestead, Florida, and introduced in 1941 (U.S. Plant Patent
No. 444) is the derivative, smaller, round-fruited variety, named
Idemor, which occurred as a limb sport. More recently, what
appears to be a similar mutation has been reported in a Bearss tree in
Morocco. Idemor has not achieved commercial importance.
Other Large-fruited Acid Limes.—Webber
(1943) described the Pond variety, which he obtained in Hawaii in
1914. It appears to closely resemble Bearss, though he
reports minor differences. The Sakhesli lime of Tunisia also
closely resembles Bearss but is obviously a much older
variety. An unnamed clone introduced by the U.S. Department
of Agriculture and described as a seedless lime of Italian origin is of
interest since it appears to be intermediate between the Mexican and
Bearss limes, although somewhat more resembling the latter.
Sweet Lime (Citrus limettioides Tan.).—The
flavor of sweet limes seems insipid to people in the United States but
is apparently pleasing in certain other countries. The Indian
or Palestine sweet lime is described below.
Indian (Palestine) (fig. 4-89)
Fruit medium in size, subglobose to oblong or short-elliptic, sometimes
faintly ribbed; base evenly rounded; apex commonly rounded; areolar
area often protruded into a low, flat nipple surrounded by a shallow
circular furrow. Seeds few, highly polyembryonic; chalazal
spot light tan (almost blond); cotyledons faint green. Rind
thin to very thin; surface smooth to very smooth with prominent oil
glands flush with surface; tightly adherent; color greenish to orange
yellow at maturity. Aroma of rind oil
distinctive. Segments about 10; axis medium in size and
semi-hollow at maturity. Flesh color straw-yellow; tender,
very juicy; flavor insipid because of lack of acid, and with slightly
bitter aftertaste. Single bloom and crop.
Tree distinctive in appearance, medium-large in size and of spreading
but irregular growth habit, with thick, thorny branches; foliage
medium-dense. Leaves pale green, medium in size, long-oval,
blunt-pointed, and characteristically cupped or rolled, with petioles
wing-margined rather than winged as in most limes. Flowers
medium-large, pure white, and new shoot growth pure green.
The Indian sweet lime is the mitha nimbu (numerous modifications and other local names) of India, the limûn helou or succari of
Egypt, and the Palestine sweet lime (to distinguish it from the
Millsweet and Tunisian limettas, commonly called sweet limes).
In India, where this fruit has been grown longer than elsewhere,
several forms are recognized that differ principally in fruit shape,
presence or absence of the nipple, and in fruitfulness. In
northeastern India, to which it is native, it has been established
(Hodgson, Singh and Singh, 1963) that the soh synteng of Assam is
the acid form of this fruit. It is similar in all respects
except: (1) the fruit is highly acid; (2) at a limited and ephemoral [sic] stage pink coloration is present in the flower buds and new shoots; and (3) the color of the chalazal spot is pinkish-purple.
The Indian sweet lime and the Tahiti lime bear slight resemblances to the galgal
or hill lemon of India and the Tunisian limetta. There are
virtually no resemblances to the small-fruited acid lime.
In California, this sweet lime is remarkably affected by climatic
influences. Desert-grown fruit differs so greatly in size,
color, form, and rind texture from that produced in the cool, equable
coastal region that the inexperienced observer would consider them to be
different fruits.
The sweet lime is
much esteemed in India, the Near East, Egypt, and Latin America and is
considered to have special medicinal values in the prevention and
treatment of fevers and liver complaints. Statistics are not
available, but the sweet lime is grown commercially in northern India
and Egypt and widely elsewhere as a garden plant. It is also a
rootstock of considerable importance in parts of India and of major
importance in Israel and Palestine.
The most unusual practice of horticultural interest in the culture of
this fruit is the universal use of rooted-cutting trees in Egypt,
whereas seedling trees are most commonly used elsewhere.
The Tunisian limetta has been classed as a sweet lime but in the
opinion of the writer is more logically considered an acidless member of
the limetta group (C. limetta). It
resembles the Indian sweet lime only in flavor and the tendency to
cupping of the leaves. The essential oil of the rind is
altogether different in aroma and typical of the other limettas, as are
all the other characters.
Columbia appears to be the best known named clonal selection of the sweet lime.
Fruits Resembling the Limes.—Synthetic
hybrids producing fruits that resemble the limes thus far seem to have
been restricted to the West Indian lime and include the lemonimes (lemon
X lime) and limequats (lime X kumquat).
Of the lemonimes only Perrine (West Indian lime X Genoa lemon) seems
worthy of mention and it has not achieved commercial
importance. Although classed and described by Webber (1943)
as a lemon, in the opinion of the writer it has greater resemblance to
and behaves more like the West Indian lime. While the fruit
is somewhat larger and the tree is said to be resistant to both lime
withertip and citrus scab, its claimed cold resistance has been found to
be insufficient for southern Florida, where some years ago it was
planted as a substitute for the West Indian lime. A freeze
wiped out the plantings, which were then replaced by the much hardier
Persian lime. Perrine originated as a hybrid made by W. T.
Swingle and associates of the U.S. Department of Agriculture in 1909 and
was named and described in 1931.
Of the limequats, which are bigeneric hybrids, three varieties have been named (for description see Webber, 1943, pp. 667-68)—Eustis (fig. 4-90),
Lakeland, and Tavares. Their importance is approximately in
that order. All are characterized by fruits that closely
resemble the West Indian lime in size, form, and composition and hence
are reasonably acceptable substitutes. Eustis and Lakeland
also closely approach the West Indian lime in color. Tavares,
however, exhibits some of the orange coloration characteristic of the
kumquat and the pink coloration of the flower buds which occurs in the
West Indian lime. All of the limequats are more
cold-resistant than the lime parent but considerably less so than the
kumquat.
None of the limequats has
achieved commercial importance for the fruit, but Eustis and Lakeland
are grown somewhat as ornamentals. In California, they are
popular as potted or tubbed plants for patios and terraces.
Eustis and Lakeland are sister hybrids of the West Indian lime and the round kumquat (Fortunella japonica), and Tavares is a similar hybrid with the oval kumquat (Fortunella margarita). They
were made by W. T. Swingle of the U.S. Department of Agriculture in
Florida in 1909 and were named and described in 1913.
In India, where natural hybrids abound, there are a number of fruits in
which lime parentage is fairly obvious. The writer observed
several natural hybrids in which both citron and kaghzi nimbu
characters were evident. There are also a number of fruits
that appear to be lemonimes, among which the most important are the
so-called Rajamundry and Baramasi lemons. The
former seems clearly to be a large-fruited lemonime of the West Indian
lime type and the latter a thornless Tahiti lime-like plant and fruit.
THE KUMQUATS (FORTUNELLA SPECIES)
Although the derivation is not given, Webber (1943, p. 639) states that
the name kumquat (cumquat) is supposed to have come from the earliest
known Chinese name, chin kan, which is translated as meaning "gold orange." In Japan, where this fruit has been grown for centuries, the name kin kan is said to have the same meaning. A generalized description is presented below:
Fruit tiny to very small, globose, obovate, oblong or oval; color
golden yellow to reddish-orange; seeds few and with green
cotyledons. Rind medium-thick (for the size of the fruit);
fleshy; surface smooth; sweet flavored but aromatic and spicy; tightly
adherent; axis small and solid. Flesh color yellowish-orange;
juice scanty; flavor moderately acid. Early midseason in
maturity. Fruit holds well on tree with little loss in
quality.
Plant an evergreen shrub or
small tree (except on certain vigorous rootstocks), fine-stemmed and
bushy, symmetrical, usually with few or no thorns; dense foliage
consisting of small mandarin-like leaves (fig. 4-91). Common species strongly cold-resistant.
Markedly resembling the other citrus fruits in general and obviously
closely related to the Calamondin and some of the small-fruited
mandarins, the kumquats were included in the genus Citrus until comparatively recently when Swingle established the genus Fortunella
(Swingle, 1915), which was soon accorded virtually universal
acceptance. The principal differences on the basis of which
the separation was made (chap. 3, this work) included the following: (1) ovary locules many fewer than Citrus
(three to five, rarely six or seven); (2) not more than two collateral
ovules per locule (as compared to four to twelve); (3) stigma very
broadly cavernous; (4) fruits very small with sweet, edible, more or
less pulpy rind; and (5) small, more or less angular flower buds.
Undoubtedly of Chinese origin and mentioned by earlier writers, the
first description of the common kumquats appears to be that of Han
Yen-chih, written in 1178 A.D. and translated by Hagerty in 1923, in
which he refers to two kinds of chin kan (kumquat). It
seems probable that in European literature the kumquat was the fruit
referred to by Ferrari (1646) as the "aurantium…minusculum, Kin kiu"
described by the Portuguese missionary Alvarus Semedus who had spent
many years in China. So far as can be determined, this fruit (Nagami or
oval form) was first introduced into Europe in 1846 by Robert Fortune, a
plant explorer and collector for the London Horticultural Society, who
found it in China (Fortune, 1846). it must have been sent to
the United States soon thereafter, for it is described and illustrated
in the February, 1850, edition of Downing's Horticulturist (Webber,
1943, p. 640). The round-fruited form Marumi was introduced
from Japan into Florida in 1885, and the Meiwa and Hongkong kumquats
were brought in by the U.S. Department of Agriculture between 1910 and
1912 (Webber, 1943). So far as the writer has been able to
ascertain, the Malayan kumquat, F. polyandra, remains to be successfully established in Europe or the United States.
The common kumquats (Nagami and Marumi forms) exhibit two distinctive
and significant climatic reactions concerned with temperature
requirement. Since growth activity occurs only at relatively
high temperatures, the trees remain inactive and semidormant in
subtropical and warm temperate climates during the fall, winter, and
spring months and exhibit growth activity only during the comparatively
short summer-growing season. As a consequence, they normally
come into bloom much later than Citrus species and enter the
condition of induced dormancy earlier. To judge from the
behavior of the oranges and mandarins, this long period of growth
inactivity coupled with photosynthetic activity must contribute
materially to their outstanding cold-hardiness. Whatever the
reasons may be, however, these two kumquats exceed the hardiest of the
citrus species in resistance to winter cold, including even the satsuma
mandarins.
On the other hand, the
size attained by the fruit is materially affected by the amount of heat
during the growing season and somewhat by the atmospheric
humidity. Thus, the fruit is larger, juicier, and less acid
in Florida than in California, and similar differences exist between
fruit grown in the hot interior districts of the latter state and in the
cool, equable coastal region.
Although the peel is edible, and the fruit may therefore be eaten whole,
the taste is too tart for most palates. The kumquat is
largely used therefore for preserving in syrup, candying, and making
marmalade. Perhaps the principal use in the United States,
however, is for decorative purposes and in gift packages of other citrus
fruits, the preparation and sale of which constitutes an enterprise of
considerable importance in Florida. Since the tree is hardy,
dwarfed and symmetrical, the foliage attractive, and the fruit small,
brightly colored, and persistent, the kumquats have been prized and much
used as ornamentals from time immemorial and this doubtless is
their most important use. On dwarfing rootstocks, principally
the trifoliate orange, they are long-lived and make excellent tubbed
plants for terraces and patios in subtropical and warm temperate regions
and conservatories elsewhere.
The
kumquats are most widely grown in China, southern Japan, and Taiwan
(Formosa), though the tropical form is confined principally to
Malaya. Elsewhere their culture occurs mainly in the United
States—in Florida primarily for the fruit for use in the gift-package
trade and in California almost exclusively for use as ornamental plants.
Kumquat Varieties
Presumably because of the fact that the seedlings are usually
weak-growing and inferior, most of the horticultural varieties—in the
Occident at least—are in fact the species clones originally
introduced. Swingle (chap. 3, this work)
recognized four species, but Tanaka (1954) considers that there are
six. The differences between several of these species are so
minor, however, as to cast doubt on the validity of some of
them. Listed in their probable descending order of
importance, they are as follows:
Nagami or Oval Kumquat (F. margarita [Lour.] Swing.) (figs. 4-91 and 4-92)
This species is the Naga or Nagami kinkan of Japan. According to Swingle (chap. 3, this work),
the most distinctive features of this species are the oblong, obovate,
or oval form of the fruit, the narrow range in number of segments
(normally four or five), the deep color and pronounced flavor of both
fruit and rind, and the comparatively large leaf and tree.
As previously indicated, this is the form which first reached the
Occident. It is vigorous and prolific and the fruit is deeply
colored, pleasantly flavored, and of good size, though the rind oil is
somewhat more pronounced than in other kumquats. It is much
the most popular variety both in the Orient and the United States.
Meiwa or Large Round Kumquat (F. crassifolia Swing.) (fig. 4-93)
This species is the Ninpo, Meiwa or Neiha kinkan of Japan. The most distinctive features of this kumquat are the short oblong to round form and relatively
large size of the fruit, the more numerous sections (commonly seven),
the very thick and sweet rind and comparatively sweet flavor, and the
low seed content (many fruits are seedless).
While Swingle originally (1915) considered it to be a valid species, he
later concluded that this variety is a natural hybrid between the oval
and round kumquats (chap. 3, this work).
It is much the best variety for eating fresh and is reported to be
widely grown in Chekiang Province of China and to some extent in Fukuoka
Prefecture of Japan. Meiwa is said to be slightly less
cold-hardy than Nagami but is increasing in popularity in the United
States.
Tanaka reports the existence
in Japan of a variegated form with striped fruits, which is a most
attractive ornamentals.23
Marumi or Round Kumquat (F. japonica [Thumb.] Swing.)
This is the Maru or Marumi kinkan
of Japan. In comparison with the oval kumquat, which it
closely resembles, the fruit of this kumquat is round or slightly
oblate, sometimes obovate, and smaller, with a thinner and somewhat
sweeter rind and a wider range in the number of segments (four to
seven). The tree is less vigorous and somewhat thorny, with
smaller, less sharply pointed leaves (chap. 3, this work).
Hongkong Kumquat (F. hindsii [Champ.] Swing.) (fig. 4-94)
This is the Mame or Hime kinkan of Japan. According to Swingle (chap. 3, this work),
this species grows wild in Hongkong and in the Chekiang and Kwangtung
provinces of China. The most distinctive features include the
small size and spiny nature of the plant and the very small,
brilliantly colored, subglobose, virtually inedible fruits that contain
three or four segments and relatively large, plump
seeds. Since the pollen-mother cells contain double the
normal number of chromosomes, Swingle considers it to have originated as
an autotetraploid.
The Hong Kong
kumquat is apparently of ancient origin, for it is rather widely
distributed in the wild and is undoubtedly the chin chu (golden bean) or shan chin kan (mountain golden mandarin) described by Han Yen-chih in 1178 A.D. and referred to by an earlier writer whom he quotes.
In modern times, however, the name golden bean kumquat has been
restricted to a cultivated diploid form, the chin tou of China or Kinzu kinkan of Japan, which Swingle considers to have originated from the wild species. According to Swingle (chap. 3, this work),
it differs from the parent species principally in having larger,
thinner, and narrower leaves, shorter and more slender spines, and
somewhat larger fruits. The flowers are also smaller.
It may be of interest to note that the fruits of the Hongkong kumquat
appear to be the smallest of the true citrus fruits.
While the Chinese are said to prize these fruits and to preserve them
for use as a spicy flavoring, elsewhere they are merely novelty
ornamentals, grown primarily as potted plants.
Changshou Kumquat (F. obovata Tan.)
The Choju kinkan
or Changshou or Fukushu kumquat of Japan is a dwarf variety that is
reported to be widely grown as a potted plant in China and also in Japan
to some extent. According to Swingle (chap. 3, this work),
it is characterized by the broadly obovate form of the fruit, a
markedly depressed apex, medium size, thin rind (for a kumquat), and a
rather large number of segments (five or six, sometimes as many as
eight). Seeds are usually few and
polyembryonic. The plant is small and thornless.
This species was established by Tanaka (1933, p. 38) but was not
accepted by Swingle who considered it to be a chance hybrid between two
of the Fortunella species.
Malayan Kumquat (F. polyandra [Ridl.] Tan.)
This little known kumquat appears to be of Malayan origin, for its
present distribution seems to be restricted to that general region and
Hainan Island. According to Swingle (chap 3, p, 332), it is a
thornless shrub with long, slender, lanceolate leaves and relatively
large, round, and thin-skinned fruits (for a kumquat), containing five
or six segments. Swingle accepted this species, though he
questioned its validity and suggested the likelihood of hybrid origin.
It appears to be grown both for the fruit and as an ornamental but not as a potted plant.
Kumquat Hybrids
Because of its marked cold-hardiness, the kumquat was early employed in
the citrus fruit breeding program of the U.S. Department of Agriculture
in Florida, and in 1909 a series of crosses was begun which resulted in
the creation of the limequats, orangequats, citrangequats, and other hybrids. Only the limequats
and citrangequats have proven to have horticultural
value. Since the former more resemble the lime and are used
as substitutes for it, they are treated with the limes. The
citrangequats, however, which are trigeneric hybrids in which a
bigeneric citrange is one of the parents, most resemble the kumquat and
hence are included here.
In this connection, it should perhaps be mentioned that Swingle (chap. 3, this work) regards the kumquat as one of the parents of the Calamondin.
The Orangequat (Fortunella sp. X mandarin).—The name given to this class of hybrid is misleading since its parentage involves a mandarin rather than a true orange (C. sinensis or C. aurantium). So far as the writer has been able to ascertain, only one cross was made and one variety named (chap. 3, this work).
Nippon
Fruit small (but larger than the kumquat), broadly oval to obovate;
orange-colored; rind relatively thick and spongy; flavor mild and pulp
acid. Matures early but holds well on tree for several
months.
Tree slow-growing, medium-small, spreading; foliage dark green.
This variety originated from a cross between the satsuma mandarin (C. unshiu) and the Meiwa kumquat (F. crassifolia) made
in Washington, D.C. by Eugene May of the U.S. Department of
Agriculture. It was described in 1931 (Swingle, Robinson, and
Savage, 1931) and introduced in 1932. Although it is a
somewhat attractive ornamental and the fruit makes excellent marmalade,
the orangequat has not become popular and remains an oddity or
collection item.
The Citrangequats (Fortunella sp. X citrange).—Combining
the cold-hardiness of the kumquat and trifoliate orange, the
citrangequats appear to be more cold-resistant than the citranges
or the Calamondin and kumquat, for they are said to succeed in regions
too cold for these fruits (Ziegler and Wolfe, 1961, p. 63).
Three varieties are described by Webber (1943, pp. 665-66), all of
which produce fruits with marked resemblances to the kumquat and two of
which are characterized by a high percentage of trifoliolate leaves.
Sinton (fig. 4-95)
Fruit small, round to oval; often necked; color deep reddish orange;
sharply acid; nearly seedless. Tree moderately vigorous,
upright, nearly thornless; leaves mainly unifoliolate.
This Oval kumquat and Rusk citrange hybrid first fruited at Sinton,
Texas, and was named and described in 1923 (Swingle and Robinson, 1923,
p. 235). It is an attractive ornamental and the fruit is
beautifully colored but highly acid.
Telfair
Fruit small, round; color yellow to orange-yellow; strongly acid; seeds few.
Tree vigorous, upright, thorny; leaves variable but mainly trifoliolate.
This is an Oval kumquat and Willits citrange hybrid, which first
fruited in Telfair County, Georgia. It was made in 1909 and
named and described in 1923 (Swingle and Robinson, 1923, p. 234).
Thomasville
Fruit medium-small, globose to oval; color yellow to orange-yellow;
acid until fully mature when it becomes edible; somewhat seedy.
Tree very vigorous, upright, thorny; leaves variable but mainly trifoliolate.
This citrangequat is of the same parentage as Telfair and was first
fruited at Thomasville, Georgia. The cross was made in 1909,
and the variety was named and described in 1923 (Swingle and Robinson,
1923, p. 230).
Presumably because of
the larger size and edibility of the fruit, it is much the most popular
variety.
THE TRIFOLIATE ORANGE (PONCIRUS TRIFOLIATA [L.] RAFINESQUE)
It is most unfortunate that there is no distinctive Occidental common name for this fruit—the karatachi of
Japan—for it is completely inedible and remarkably different from the
orange, so much so that it cannot properly be regarded as an orange in
any respect. Indeed it is included in this treatment only
because: (1) trifoliate orange and some of its hybrids provide valuable
rootstock varieties; and (2) the fruits of some of the hybrids approach
edibility.
The plant is a highly
distinctive deciduous shrub or small tree with very large stout spines
and small compound leaves with winged petioles and three
leaflets. In the smaller stems, the pith is discontinuous, in
the form of transverse plates (continuous in Citrus and Fortunella). The
flower buds are small, single, lateral, protected by small fleshy
scales, and are formed early in the summer preceding
bloom. The flowers are very short-stalked with five white,
thin, papery petals, numerous stamens of which the filaments are free,
and a compound pistil. The ovary of the pistil is highly
pubescent and contains six to eight locules, commonly seven.
The fruits are small, oblate or obovoid to globose, and dull
lemon-yellow. The rind is relatively thick, soft, densely
pubescent, and has abundant oil glands. The juice is scanty
and acid and the somewhat slimy pulp contains numerous droplets of acrid
oil which impart a highly unpleasant taste. The seeds are
plump and polyembryonic. The fruit normally ripens in late
summer or early fall and drops soon thereafter, though off-bloom fruit
may mature later.
Climatically, this
fruit belongs to the warm-temperate group, for it is nearly as
cold-hardy as the Oriental persimmon and some of the peaches and
Japanese plums. The rest in the flower buds is comparatively
light, however, and in subtropical climates is sometimes broken by
excessively hot fall weather, with resultant
bloom. Trifoliate orange normally blossoms with the earliest
deciduous fruit trees. When used as a rootstock for the
evergreen citrus fruits and kumquats, the trifoliate orange seems to
accentuate their normal self-induced dormancy and to somewhat enhance
their natural cold-hardiness, presumably because of its deciduous nature
and hence true dormancy during late summer, fall, and
winter. Probably because of its requirement for chilling,
this fruit does not appear to be climatically adapted to either tropical
or very hot subtropical climates with mild winters. These
facts serve to explain why the natural range of climatic adaptation of
the trifoliate orange extends into regions much too cold for citrus
fruits and why its use as a rootstock is largely restricted to the
colder portions of the subtropics.
Undoubtedly native to central or northern China, where it is widely
distributed and has been grown for thousands of years, the trifoliate
orange is thought to have reached Japan sometime around the eighth
century (chap. 3, this work) [sic] The first known description of it and reference to its use as a rootstock occurs in Han Yen-chih's Chü Lu,
written in 1178 A.D. and translated in 1923. The writer has
not been able to determine when the trifoliate orange reached Europe,
but it is known that William Saunders of the U.S. Department of
Agriculture received it from Japan in 1869.
As an outdoor ornamental, this plant is commonly grown in the warm
temperate regions of China, Japan, western Europe, and eastern United
States and is sometimes used as a hedge, for which it is very
effective. It has long been the most important rootstock in
Japan, primarily for the satsuma mandarins, and increasingly is being
employed in Australia, California, and Argentina. However, it
is susceptible to the exocortis virus, which has been found to be
widely prevalent in citrus clones. It is said that from
ancient times the Chinese have used preparations of the fruit for
medicinal purposes.
Although the genus Poncirus was established by Rafinesque in 1815 (Ziegler and Wolfe, 1961), Linnaeus included it in the genus Citrus. It
was not until a hundred years later that Swingle gained acceptance for
its restoration to separate standing. Only one species is
recognized, trifoliata, which André in 1885 designated as triptera. As a consequence, until comparatively recently the trifoliate orange has been referred to as Citrus triptera in
the French literature. The existence of two groups with
respect to flower size—the small-flowered and large-flowered—has long
been recognized. In California, the former seems to have a
somewhat higher temperature requirement for growth and enters the rest,
matures the fruit, and becomes dormant much earlier, which may be
associated with its greater cold resistance when used as a
rootstock. In Japan, where this rootstock is extensively
employed, it is believed that the large-flowered forms are more dwarfing
(Bitters, 1964), but this has not been confirmed in California.
Rootstock Trifoliate Selections
Because of renewed interest in the use of trifoliate orange rootstock,
notably in California where it affords important advantages, during
recent decades collections have been made of materials assembled from
different parts of the world or recovered from outstanding local orchard
trees. While years will be required for their evaluation for
use as rootstocks, comparison of nursery progenies clearly indicates
the existence of a number of clones, some of which may ultimately
justify naming as horticultural varieties.
At the present time, however, the only clone in California whose
behavior is sufficiently well established to warrant naming is Rubidoux (fig. 4-96). The
parent tree of Rubidoux was planted on the old Rubidoux site of the
University of California Citrus Research Center, Riverside, about 1907
and came from the R. M. Teague Nursery Company at San Dimas,
California. While it belongs to the small-flowered group and
has medium vigor in comparison with others, the writer knows of no other
distinctive characteristics useful in its description or
identification, though there may be such.
Ornamental Trifoliate Varieties
Several dwarfed ornamental varieties are said to exist in the
Orient. According to Swingle (chap. 3, this work), the most important and interesting of these is the Japanese hiryo
or Flying Dragon variety, which he introduced to the United States in
1915. Grown primarily as a potted plant, this is a highly
dwarfed variety with very small leaves, the leaflets of which are
commonly reduced to linear filaments, and slender crooked branches armed
with large, downward-curved spines. It is a curious
monstrosity which he has accepted—unnecessarily, in the opinion of the
writer—as the botanical variety monstrosa of T. Ito.
Trifoliate Hybrids
Although remarkable different from Citrus in nearly all respects, Poncirus hybridizes
freely with the citrus species. Because of its outstanding
cold-hardiness, it was early used in the citrus breeding program of the
U.S. Department of Agriculture. Beginning in Florida in 1897
and continuing for several decades, many crosses were made between the
trifoliate orange and citrus species and some with other
genera. From this work came a series of bigeneric hybrids—the
citranges, citrumelos, citrandarins, citremons, citradias, and
citrumquats—a few of which are of horticultural importance or promise.
The Citranges (Poncirus X C. sinensis).—The
influence of the trifoliate orange is strongly marked in the citranges
as evidenced by the trifoliolate nature of their leaves, the acidity and
bitterness of their fruits, and the cold-hardiness of the
trees. The influence of the sweet orange is shown, however,
in the evergreen nature of the trees, though a few are semi-deciduous,
and in their greater vigor. Additionally, the fruit is
usually much larger and more orange-like in appearance. In
general, however, the citranges exhibit some degree of intermediacy
between the parental species. Of great horticultural
importance in connection with their use as rootstocks is the fact that
with few exceptions they come remarkably true from seed. They
are highly polyembryonic and apparently rarely develop zygotic embryos
(Swingle, 1927).
The term citrange
was announced and the first variety named and described in 1904 (Webber
and Swingle, 1905) and subsequently a dozen or more have been
added. For descriptions of most of them the reader is
referred to Webber (1943, pp. 656-65) and the literature he cites.
In Webber's opinion, the citrange varieties that most closely approach
the sweet orange in size, appearance, and edibility in the fresh state,
and hence may be useful as juice fruits for dooryard planting in regions
too cold for oranges and mandarins, are Morton, Coleman, and
Savage. He also recommends them as ornamentals.
Since, in general, the citranges exhibit some of the most desirable
features of the trifoliate orange combined with the greater vigor and
wider range of soil adaptation of the sweet orange, some of them are
currently of promise or already have achieved importance as
rootstocks. Principal among these are Carrizo, Rusk, and
Troyer, which are described below.
Carrizo
Carrizo is indistinguishable from Troyer
and of the same parentage. Savage and Gardner (1965) have
recently presented convincing evidence that Carrizo and Troyer are in
fact a single clone which originated as the zygotic seedling (CPB
4-5019) from a cross of Washington navel and trifoliate orange made by
the senior author in 1909 under the direction of W. T. Swingle of the
U.S. Department of Agriculture instead of two sister seedlings as had
been assumed (Mortensen, 1954).
In
1923, Swingle had 200 seedlings of this then unnamed clone sent to the
Winter Haven substation (No. 19) near Carrizo Springs,
Texas. In 1938, he suggested it be named Carrizo, either
forgetting that he had already given it the name Troyer in 1934, which
seems unlikely, or because he failed to recognize its identity, which
seems surprising.
Bitters reports
that its field performance has differed somewhat from Troyer, which is
difficult to understand in light of the conclusions set forth above.24
Rusk (fig. 4-97)
Fruit rather small, oblate to spherical; smooth and virtually glabrous;
color deep orange with reddish flush. Rind thin and tightly
adherent; segments about 10. Flesh color orange-yellow; very
juicy; flavor sprightly acid and only slightly bitter. Seeds
few and highly polyembryonic. Early in maturity.
Tree vigorous, tall-growing, productive, and hardy; foliage evergreen
to semi-deciduous and dense, consisting of moderately large trifoliolate
leaves.
Rusk, a Ruby orange and trifoliata hybrid,
is one of the oldest citranges, having been created by Swingle in 1897
and described and released in 1905 (Webber and Swingle). It
was named in honor of J. M. Rusk, the first Secretary of Agriculture of
the United States.
The tree is an
attractive ornamental and the fruit is juicy and approaches edibility
more closely than most citranges. Its low seed content
mitigates against use as a rootstock.
Rusk is currently of greatest interest and importance in Florida.
Troyer (fig. 4-98)
Fruit small, oblate to spherical; smooth and nearly glabrous; color
light orange. Rind medium-thick, with numerous oil glands;
tightly adherent. Segments 9 to 10 and axis
solid. Flesh color light yellow; juicy; flavor strongly acid
and bitter. Seeds numerous, plump, and highly
polyembryonic. Season of maturity early.
Tree vigorous, upright-spreading, and medium-large with rather slender,
thorny branchlets; foliage moderately dense, evergreen to
semi-evergreen. Leaves dark green, medium in size, and mainly trifoliolate, occasionally unifoliolate. Productive and hardy.
This variety originated as a hybrid of the Washington navel orange
crossed with trifoliate orange pollen (hence is actually a citruvel)
that was made by E. M. Savage, under the direction of W. T. Swingle of
the U.S. Department of Agriculture, at Riverside, California, in
1909. In 1934, Swingle named it for A. M. Troyer, on whose
place at Fairhope, Alabama, it was first fruited. The rise of
this rootstock to prominence in California has been
spectacular. Within less than twenty-five years from the
first field trial it has become the rootstock most employed and is much
in demand elsewhere.
Other Trifoliate Hybrids.—Of the complex hybrids in which a citrange is one of the parents, currently only the citrangequats (Fortunella X citrange)
have sufficient horticultural value to be worthy of
mention. Since they most resemble the kumquat parent, they
are included under Fortunella.
While several citrumelos (Poncirus X C. paradisi), citrandarins (Poncirus X C. reticulata and other mandarin species) and citremons (Poncirus X C. limon)
are currently under trial as rootstocks and for other purposes, in the
opinion of the writer none of the named or otherwise designated clones
is currently sufficiently important to warrant inclusion in this
treatment, some of them appear to be promising.
ACKNOWLEDGMENTS
Rather obviously, it would have been impossible to prepare this
treatise without the invaluable assistance so generously provided by
colleagues both at home and abroad. Indeed, for the degree to
which it may have achieved its objectives of breadth of scope,
accuracy, and adequacy, the credit is largely
theirs. Principal among those to whom grateful acknowledgment
is made are the following:
United States: F. E.
Gardner and P. C. Reece, U.S. Horticultural Station, Orlando, and A. P.
Pieringer, Citrus Experiment Station, Lake Alfred, both in Florida; R.
T. Brown, Plaquemines Parish Experiment Station, Port Sulphur,
Louisiana; E. O. Olson, U.S. Horticultural Station, Weslaco, Texas; R.
H. Hilgeman, Citrus Branch Station, Tempe, Arizona; and R. G. Platt and
W. P. Bitters, Citrus Research Center, University of California,
Riverside.
West Indies: Egbert Tai, University of the West Indies, St. Augustin, Trinidad.
South America: S.
Moreira and A. A. Salibe, Instituto Agronomico, Campinas, São Paulo,
Brazil; and E. Sartori, University of Buenos Aires, Buenos Aires,
Argentina.
Australia and New Zealand: E.
C. Levitt and R. J. Benton, Department of Agriculture, Sydney, New
South Wales; and W. A. Fletcher and H. M. Mouat, Department of
Scientific and Industrial Research, Auckland, New Zealand.
Japan:
M. Nishiura, Horticultural Research Station, Okitsu; and Y. Tanaka,
Citrus Experiment Station, Komagoe, both in Shizuoka Prefecture.
South Africa: W. J. Basson and R. H. Marloth, Citrus and Subtropical Fruit Research Institute, Nelspruit, Eastern Transvaal.
Mediterranean Basin: H.
Chapot, Narenciye Arastirma Istayonu, Antalya, Turkey (for the entire
basin); E. Gonzalez-Sicilia, Estación Naranjera de Levante, Burjasot,
Spain; R. Khalidy, American University, Beirut, Lebanon; H. O. Ruck,
Food and Agriculture Organization, Rome (for Israel); and L.
El-Mahmoudi, Ministry of Agriculture, Orman-Giza,
Egypt. Special thanks are due to Dr. Henri Chapot for making
available his vast knowledge of the varieties of the Mediterranean basin
and Near East and for suggestions, criticisms, and many of the
photographs employed herein. Dr. Chapot is, without doubt,
the principal worker in this field and the leading authority.
Of those who so kindly reviewed the final manuscript, special gratitude
for their very great helpfulness is expressed to W. P. Bitters and
Walter Reuther, Department of Horticultural Science, Citrus Research
Center, University of California, Riverside. Deep
appreciation is also expressed to Mr. Harry Lawton whose editorial
review of the manuscript resulted in great improvements in organization,
arrangement, and presentation of the text.
The writer assumes responsibility for the errors that will be found and
asks that they be brought to the attention of the editor in subsequent
revisions.
FOOTNOTES
2. Personal communication from A. A. Salibe to the author, dated May 25, 1964.
3. Letter to the writer from E. C. Levitt, government citrus specialist in New South Wales, dated May 7, 1963.
4. Letter to the writer from E. C. Levitt, government citrus specialist in New South Wales, dated May 18, 1964.
5. Letter to writer from H. Chapot, dated March 24, 1964.
6. Letter to the writer from H. Chapot, dated March 24, 1964.
7. Letter to the writer from H. Chapot, dated March 24, 1964.
8. Chapot and Huet (1964) recently reported differences in the shape of the seeds, which are deltoid with a pronounced beak at the chalazal end for the acidless oranges. They also noted minor differences in flesh color and aroma.
9. Also reported in a letter from E. Gonzalez-Sicilia to the writer, dated June 25, 1963.
10. Letter to the writer from H. Chapot, dated December 20, 1963.
11. Letter to the writer from E. Gonzalez-Sicilia, dated June 25, 1963.
12. Letter to the writer from H. Chapot, dated May 6, 1964.
13. Letter to the writer from M. Nishiura, National Horticultural Research Station, Okitsu, dated May 30, 1963.
14. Letter to the writer from M. Nishiura, dated May 30, 1963.
15. Letter to the editor from W. P. Bitters, dated August 6, 1965.
16. Letter to the writer from H. E. Wahlberg, dated August 5, 1964.
17. For a detailed discussion of these differences, the reader is referred to the excellent paper by Chapot (1950a).
18. Letter to the editor from W. P. Bitters, dated August 6, 1965.
19. Letter to the writer from E. C. Levitt, dated September 24, 1963.
20. Letter to the writer from H. Chapot, dated June 24, 1963.
21. Letter to the editor from W. P. Bitters, dated August 6, 1965.
22. Letter to the writer from H. Chapot, dated September 22, 1963.
23. Unpublished report to the writer from T. Tanaka, submitted in July, 1955.
24. Letter to the editor from W. P. Bitters, dated August 6, 1965.