From the Manual Of Tropical And Subtropical Fruits
by Wilson Popenoe
The Loquat
Cultivation
The
climatic requirements of the loquat, except as an ornamental plant, are
distinctly subtropical. It is not successful in the hot tropical
lowlands, nor can it be grown for fruiting purposes in regions subject
to more than a few degrees of frost. Cool weather during part of the
year and a rainfall of 15 to 50 inches (with artificial irrigation
where the dry season is severe) suit it best. These conditions are
found in southern Japan, in parts of southern California, along the
shores of the Mediterranean, and in several other regions. It has been
noted in Japan that the best loquat situations always lie close to the
sea; and in California much finer fruit has been produced near the
coast than in the foothill tracts twenty to thirty miles inland. Thus
it seems that the mild climate of the seacoast is peculiarly favorable
to the development of the fruit.
While mature trees have
withstood temperatures as low as 10° above zero without serious
injury, the flowers and young fruits may be killed by temperatures only
a few degrees below freezing; hence loquats cannot be produced
successfully where heavy frosts may occur at the time of flowering.
Condit notes: "Frost coming when the fruit is less than half grown may
result in killing the seeds only, while the flesh continues to develop,
so that seedless fruits mature. On the other hand, frost may have
somewhat the same effect as sunburn, injuring the tissues and causing
them to shrink or to develop irregularly."
When grown in regions
where the weather during the ripening season is extremely hot and dry,
the fruit is subject to sun-scald or sunburn. The exposed surface
withers and turns brown, and the product is rendered unfit for market.
If, on the other hand, the weather is cool and foggy during the
ripening season, the fruit lacks sweetness and flavor.
Sandy
loam is considered the ideal loquat soil, and it should be of good
depth. Several other types of soil have proved satisfactory; thus, in
southern California good orchards have been produced on heavy clay of
the adobe type, and in Florida the shallow rocky soils of the Homestead
region on the lower east coast have given excellent results. Deep sandy
soils, when of little fertility, are not suitable. Frank N. Meyer
points out that the best loquat orchards in China are situated on low,
rich, moist land.
In California orchards, loquat trees are
planted 12 to 24 feet apart. When planted on the square system, they
should not be nearer than 20 feet. Close planting has been practiced in
Orange County, where the rows are set 24 feet apart and the trees 12
feet apart in the row. This is believed to result in greater regularity
and uniformity of production than wider planting. March and April are
good months for planting in California; late September and October are
also suitable. In southern Florida the best time is probably in the
autumn.
The amount of tillage given the orchard varies in
different regions. Condit says: "Clean culture may be practiced
throughout the season, but the growth either of a winter or a summer
leguminous cover-crop is much more advisable." For a winter cover-crop,
the natural vegetation which springs up in California with the arrival
of the rains may be allowed to grow until it reaches its maximum
development, when it should be cut with a mowing-machine and plowed
under after the fruit is harvested. Following this the ground should be
cultivated and a summer cover-crop such as buckwheat or the
whip-poor-will cowpea should be planted. "Winter cover-crops may be
planted as early as September, in which case they may have made
sufficient growth to be turned under before the harvest begins. This is
not always possible, especially if an early variety of loquat is grown;
in fact, it is a question whether it is advisable to plow or work the
ground deeply or at all during the setting and maturing of the fruit."
In Florida and other regions different methods of cultivation may be
required, but the liberal use of green cover-crops seems universally
desirable.
In addition
to cover-crops, stable manure is often used to enrich the land in
California orchards. Bearing loquat trees exhaust the fertility of the
soil rapidly and it is necessary to replenish the supply of plant-food
annually if fruit of large size is to be expected. Condit observes:
When the average California soil begins to fail from heavy production,
nitrogen is likely to be the first crop limiter; after nitrogen,
phosphoric acid, and after phosphoric acid, potash." Particular care
should be taken, therefore, to see that the supply of nitrogen is
sufficient to meet the demands of the tree. C. P. Taft, of Orange,
California, has found the green cover-crops of great value in this
connection. E. Pillans, Government Horticulturist at the Cape of Good
Hope, says that a yearly application of well-rotted stable manure is
amply repaid by larger crops and increased size of fruit.
The
loquat groves of Japan are said to be fertilized with litter, weeds
from the roadsides, and, recently, with commercial fertilizers. Condit
advises the application of 15 cubic feet of stable manure biennially to
each bearing tree.
It is ordinarily considered that the amount of
water required by loquat trees corresponds closely to that needed by
citrus fruits. Probably it would be more accurate to say that the
loquat is more drought-resistant than any of the citrus fruits, but
that the best results are obtained when the orchard is irrigated as
liberally as the citrus orchard. In California there is usually
abundant rainfall at the time the fruits are approaching maturity; in
other regions, or in California if the season is abnormally dry, it may
be desirable to supply water at this time, since the fruits only
develop to large size when there is abundant moisture in the soil. In
southern France the tree is said not to do well on soils which are
over-moist in winter.
The young tree should be headed 24 to 30
inches above the ground, and three to five main branches forced to
develop. The loquat is a compact grower, and the mature tree requires
much less pruning than most of the temperate-zone fruits. It has been
found by C. P. Taft, however, that a certain number of branches must be
cut out from time to time, in order to limit the amount of fruiting
wood and to admit light to the center of the tree. It must be
remembered that the tendency of the loquat is to overbear, and for the
production of commercially valuable fruit this must be checked by
pruning and thinning. The best time for pruning is soon after the crop
has been harvested.
Propagation
In
many countries it is still the custom to propagate the loquat by seed,
but in regions where the commercial cultivation of this fruit has
received serious attention, this method has been replaced by budding
and grafting. Seedling loquats are no more dependable than seedlings of
other tree-fruits. As ornamental trees for parks and dooryards they can
be recommended, but they will not serve when commercially marketable
fruit is required.
Choice named varieties are budded or grafted
on seedling loquat stocks or on the quince. Other plants have been used
as stock-plants, but have not proved altogether satisfactory.
When
budded on quince the tree is dwarfed. This stock is easy to bud; and it
is believed to produce a tree which bears at an early age, while its
fibrous root-system readily permits of transplanting. In spite of these
advantages it is considered unsatisfactory in Florida, and in
California it is commonly held that the seedling loquat is preferable.
To produce stock-plants, loquat seeds may be planted singly in
four-inch pots; they may be sown in flats of light soil and later
transplanted; or they may be germinated in moist sand or sawdust and
potted off as soon as they are 3 or 4 inches high. Potting soil should
be light and loamy. After the young plants are 8 inches high, they may
be planted in the field in nursery rows. When the stems are about 1/2
inch in diameter at the base, the plants are ready for budding or
grafting.
In California, budding is best done in October or
November. Bud wood should be of young smooth wood, preferably that
which has turned brown and lost its pubescence and from which the
leaves have dropped. Shield-budding is the method used (a description
of the operation will be found in the chapter on the avocado). The buds
should be cut at least 1 1/2 inches long. After inserting them in
T-incisions made in the stocks at a convenient point not far above the
ground, they are tied with raffia, soft cotton string, or waxed tape.
Three or four weeks later the wraps should be loosened to keep them
from cutting into the stock, and the eye should be left exposed. The
wraps should not be finally removed until the bud has made several
inches' growth. In California the stock-plant is cut off 2 or 3 inches
above the bud in early spring. This usually forces the bud to grow, but
sometimes it shows a tendency to lie dormant, and many adventitious
buds develop around the top of the stock. These must be removed as fast
as they make their appearance.
In Florida it has been found that buds unite readily with the stock-plant, but that it is difficult to force them into growth.
For
this reason grafting has superseded budding in that state. The stocks
should be of the same size as for budding, and the cion should be of
well-matured wood. Cleft-grafting is the method commonly employed.
The
young trees should be stake-trained in the nursery, and headed 24 to 30
inches above the ground. In a year from the time of budding or grafting
they should be ready for transplanting.
In California, budded or
grafted trees begin to bear the second or third year after they are
planted in the orchard, but they cannot be expected to produce
commercial crops until four or five years old. According to Condit, a
ten-year-old tree should produce 200 pounds of fruit. Early in the
season, the latter part of February and all of March, prices are high.
Fancy fruit will bring 25 to 35 cents a pound at this time. Later, in
May and June, the average price drops to 5 cents and occasionally
lower, but fancy fruit rarely sells for less than 8 to 10 cents a
pound. It is the opinion of experienced loquat-growers that the gross
returns from an orchard should be $300 to $500 an acre; more than this
has been obtained in some instances. The advisability of planting early
varieties, in order to place the crop on the market while prices are
high, is emphasized by all growers. If late fruit is to be produced, it
should be of large-fruited varieties which ship well; otherwise the
profits will be small.
Yield and Picking
The
loquat tree is productive, and a regular bearer. Barring crop failures
due to severe frosts at flowering time, the trees rarely fail to
produce well every year. Their tendency is to overbear, with the result
that the fruits are apt to be undersized. It has been profitable to
thin the crop, since the increased size of the fruits remaining on the
tree more than compensates for the loss of those removed. The practice
of experienced loquat growers in California is to clip out the ends of
the fruit-clusters with a pair of thinning-shears: this should be done
as soon as the young fruits have formed.
Where choice
varieties are grown, and where birds and insects are troublesome, it
has been profitable, in a small way, to protect the fruit by inclosing
each cluster in a cloth or paper bag. The Japanese, who practice
bagging in connection with the production of fancy loquats, find that
it results in larger fruit and a greater degree of uniformity in
ripening.
The season during which loquats are marketed in
California extends from the latter part of February to June. A given
variety may ripen several weeks earlier in one locality than in
another. In Florida the season is considerably earlier than in
California. The fruits should be left on the tree until they are fully
ripe, unless it is desired to use them for jelly or for cooking. Unripe
the loquat is decidedly acid, whereas the fully ripe fruit is sweet and
delicious. Clippers such as are used by orange-pickers are employed in
gathering the fruit. Sometimes whole clusters can be picked, and again
it may be necessary to clip off two or three ripe fruits and leave the
remaining ones to mature.
The fruit is sorted and graded by
hand. For shipping to near-by markets it is packed in thirty-pound
wooden boxes ("lug boxes") without the use of excelsior, straw, or
other soft material to prevent bruising. For distant markets smaller
packages and considerable care will be required, since the fruit is
bruised rather easily.
Pests and Diseases
The principal enemies of the loquat in California are pear-blight (Bacillus amylovorus Trev.) and loquat-scab (Fusicladium dendriticum var. eriobotryce
Scalia). Condit says of the former: "The pear blight is a serious enemy
of the loquat at times, blossom blight often being especially abundant
on trees during the spring months. Infected twigs should be cut off
well back of the diseased area and burned, care being taken to
sterilize the pruning shears in alcohol or formalin after each cut so
as to reduce the danger of further infection. Occasionally entire trees
are killed by the blight, which gradually extends downward from the
branches into the trunk, although in most cases the disease does not
seem to progress much beyond the branches. Some varieties are more
susceptible than others. For example, the Advance is quite resistant
and the trees of the Victor, which were very susceptible when young,
have in later years become more or less immune; the Champagne showed
considerable blossom blight in the spring of 1914, but to no greater
extent than young trees of other varieties. The trees seem to gain
resistance as they grow older."
In regard to the scab he says:
"This is reported to be a serious disease of the loquat in Australia.
The fruit is attacked when half grown by brownish black spots, which
soon extend, stop its further development, and disfigure its
appearance. The fleshy part of the fruit becomes desiccated and the
skin seems to cling to the stones. A large proportion of the crop may
in a short space of time be rendered absolutely unsalable. It is also
well known in Italy upon the leaves. In California the scab is quite
common both on nursery and bearing trees, attacking both leaves and
fruit. . . . Spraying with Bordeaux mixture after the blossoms have
fallen and the fruit is setting should prove an effective remedy."
In Florida the flowers are sometimes blighted by the an-thracnose fungus (Colletotricham gloeosporioides Penz.). Bordeaux mixture, prepared according to a 3-3-50 formula, should be used to combat this disease.
E.
O. Essig 1 mentions four insects which occasionally attack the loquat
in California. One of these is the well-known codlin-moth (Cydia pomonella L.). Another is the green apple aphis (Aphis pomi DeGeer), and the remaining two are scale insects, one the San Jose scale (Aspidiotus perniciosus Corn-stock), and the other the Florida wax scale (Ceroplastes floridensis
Comstock). None of these insects is a serious pest at present. In other
countries the fruit is sometimes attacked by the Mediterranean
fruit-fly (Ceratitis capitata Wied.) and the Queensland fruit-fly (Bactrocera tryoni Froggatt). In India the anar caterpillar (Virachola isocrates Fabr.) bores in the fruit.
Varieties
The
regions in which named varieties of the loquat have been developed are
China, Japan, Queensland, India, Sicily, Algeria, and California.
Little
is known of the Chinese varieties. Frank N. Meyer observed several in
his travels in China, but mentioned specifically only one, the
pai-bibaw, or white loquat. T. Ikeda lists forty-six varieties which
are cultivated in Japan, but only nine of them are important. One of
them, Tanaka, has been introduced into the United States by David
Fairchild and into Algeria by L. Trabut. Four sorts are listed by the
Government Botanical Garden at Saharanpur, India, but only one, the
Golden Yellow, is recommended by A. C. Hartless, Superintendent of the
Garden. The Queensland varieties are not extensively planted, and
probably are not so good as those of California. Out of five or six
named forms which have originated in Italy (including Sicily), not one
has been planted extensively. More than fifteen varieties have been
described from Algeria, but most of them have already been discarded.
One, named Taza, which Trabut produced by crossing Tanaka and one of
the best Algerian loquats, is considered meritorious.
Most of
the improved sorts at present cultivated in California and Florida have
been produced by C. P. Taft of Orange, California. Taft has done more
than any other man in the United States to improve the loquat. His
method of procedure has been to grow a large number of seedlings and
select the most desirable ones. In this way he has established eight
named varieties, of which Champagne, Advance, Early Red, Premier, and
Victor are the best.
Little attention has been devoted to the
classification of loquat varieties. Takeo Kusano, professor in the
Imperial College of Agriculture and Forestry at Kagoshima, states that
the Japanese classify them into two groups, called Chinese and
Japanese. The Chinese type is large, pyriform, and deep orange-colored,
while the Japanese is smaller, lighter colored, and sometimes slender
in form. This classification may correspond to one suggested in 1908 by
L. Trabut of Algiers. Trabut's two groups were defined, one as having
crisp white flesh and the other orange or yellow flesh.
The
Chinese group, so far as is known at present, includes only
late-ripening varieties. The flesh differs in texture from that of
loquats belonging to the Japanese group, while the flavor is very
sweet. Kusano states that Tanaka belongs to this class. The variety
known in California as Thales, which is thought by some to be identical
with Tanaka or very close to it, appears also to belong to the Chinese
list.
The Japanese group includes the loquats of California
origin, such as Champagne and Premier. These fruits have not the firm
meaty flesh of the Chinese group, but are more juicy, and also are
distinct in flavor. The flesh is whitish or light-colored, except in
the variety Early Red.
The varieties described below are the
important ones cultivated in the United States at the present time. For
others of minor value, the reader is referred to Condit's bulletin and
to the articles by Trabut in the Revue Horticole de l'Algerie.
Advance
- Shape pyriform; size large, weight 2 1/2 ounces, length 2 1/2 inches,
breadth 1 3/8 inches; base somewhat tapering; apex narrow, the basin
medium deep, narrow, abrupt, corrugated; the calyx-segments short,
converging, the eye closed; fruit-cluster large, compact; surface
downy, deep yellow in color; skin thick and tough; flesh whitish,
translucent, melting and very juicy; flavor subacid, very pleasant;
quality good; seeds commonly 4 or 5, the seed cavity not large. Season
March to June at Orange, California.
This variety was originated by
C. P. Taft of Orange, California, in 1897. It is a productive variety,
and the fruit-clusters are large and handsome.
Champagne
- Shape oval to pyriform; size large, weight 2 ounces, length 2 1/2
inches, breadth 1 1/2 inches; base tapering, slender; apex flattened,
rather narrow, the basin shallow, narrow, flaring, and the
calyx-segments broad, short, the eye small, open; fruit-cluster large,
loose; surface deep yellow in color with a grayish bloom ; skin thick,
tough, somewhat astringent; flesh whitish, translucent, melting, and
very juicy, flavor mildly subacid, sprightly and pleasant; quality very
good; seeds 3 or 4, the seed cavity not large. Season late April and
May at Orange, California.
Originated by C. P. Taft at Orange,
California, in 1908. Taft considers it superior to his other varieties
in flavor. It is precocious and productive.
Early Red
- Shape oval pyriform to oblong pyriform; size medium large, weight 2
ounces, length 2 1/2 inches, breadth 1 3/4 inches; base tapering
slightly; apex broad, flattened, with the basin shallow, narrow,
abrupt, the calyx-segments short, broad, the eye small and closed;
fruit-cluster compact; surface yellowish orange, tinged with red in the
fully ripe fruit; skin thick, tough, acid; flesh pale orange,
translucent, melting and very juicy; flavor very sweet, pleasant;
quality good; seeds 2 or 3, the seed cavity not large. Season February
to April at Orange, California.
The Early Red loquat was originated
by C. P. Taft of Orange, California, in 1909. This is the earliest
variety known in California. It is valuable for commercial cultivation
in regions that are free from severe frosts.
Premier
(Fig. 32). - Shape oval to oblong-pyriform; size large, weight 2 1/2
ounces, length 2 1/2 inches, breadth 1 3/4 inches; base tapering
slightly; apex flattened, the basin shallow, moderately broad, rounded,
the calyx-segments short, the eye large, nearly open; surface
orange-yellow to salmon-orange in color, downy; skin moderately thick
and tough; flesh whitish, translucent, melting and juicy; flavor
subacid, pleasant; quality good; seeds 4 or 5, the seed cavity not
large. Season April and May at Orange, California.
Fig. 32. The Premier loquat,
of California origin which has been planted commercially. (X 1/3)
Originated by C. P. Taft of Orange, California, in 1899. It is a good variety for home use, but not a good shipper.
Tanaka
- Shape commonly obovoid, weight 2 to 3 ounces. L. Trabut says of it:
"Tanaka is characterized by a beautiful color, remarkable size, firm
flesh of rich color, agreeable perfume, and little acidity. The
proportion of flesh to seeds is large. This loquat owes to the
consistence of its flesh unusual keeping quality, - -it can be handled
without turning black. Left for a week it wrinkles and dries but does
not rot. Among the plants, grafted on quince, which were introduced
from Japan, two subvari-eties can be distinguished; one with
pear-shaped fruits, the other subspherical. Tanaka is vigorous, the
leaf a little narrower than in our loquats. The tree is productive."
Tanaka is famed as the largest loquat in Japan, and one of the best. It
has been planted in Algeria and in California.
Thales
(Fig. 33). - Shape round to pyriform; size large, weight 2 1/4 to 2 3/4
ounces, length 2 5/8 inches, breadth 1 3/4 to 2 inches; base rounded;
apex flattened, the basin shallow and flaring, the calyx-segments broad
and short, eye open or closed; surface yellow-orange to orange in
color; skin not thick, tender; flesh orange-colored, firm and meaty,
juicy; flavor sweet, suggesting the apricot; quality good; seeds 4 or
5, the seed cavity not large. Season April to June at Placentia,
California.
Fig. 33. Thales loquat, late ripening, large, and of excellent quality. (X about \)
Syns.
Placentia Giant, Gold Nugget. Introduced into California, without name,
from Japan betwen 1880 and 1890. It is a large, handsome fruit, and
possesses unusually good shipping qualities. It is considered to be
very close to Tanaka, if not synonymous with that variety.
Victor
(Fig. 34). - Shape oblong-pyri-form; size large, weight 2 1/2 ounces,
length 2 1/4 inches, breadth 1 3/4 inches ; base tapering slightly;
apex slightly flattened, with a shallow, flaring basin; fruit-cluster
large, loose; surface deep yellow in color; skin moderately thick and
tough; flesh whitish,-translucent, melting, very juicy; flavor sweet,
not very rich; quality good; seeds 3 to 5, the seed cavity
medium-sized. The season of this variety is May and June at Orange,
California.
Fig. 34. The Victor loquat. (X about 11/3)
Originated
by C. P. Taft of Orange, California, in 1899. A large and showy fruit,
but not considered valuable in California because it ripens late in the
season. It is considered especially good for canning.
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