From the book
Fruits of Warm Climates
by Julia F. Morton
Lychee
Litchi chinensis Sonn.
Nephelium litchi Cambess
SAPINDACEAE
The lychee is the most renowned of a group of edible fruits of the soapberry family, Sapindaceae. It is botanically designated Litchi chinensis Sonn. (Nephelium litchi
Cambess) and widely known as litchi and regionally as lichi, lichee,
laichi, leechee or lychee. Professor G. Weidman Groff, an influential
authority of the recent past, urged the adoption of the latter as
approximating the pronunciation of the local name in Canton, China, the
leading center of lychee production. I am giving it preference here
because the spelling best indicates the desired pronunciation and helps
to standardize English usage. Spanish and Portuguese-speaking people
call the fruit lechia; the French, litchi, or, in French-speaking
Haiti, quenepe chinois, distinguishing it from the quenepe, genip or
mamoncillo of the West Indies, Melicoccus bijugatus, q.v. The German word is litschi.
Plate XXXII: LYCHEE, Litchi chinensis
Description
The
lychee tree is handsome, dense, round-topped, slow-growing, 30 to 100
ft (9-30 m) high and equally broad. Its evergreen leaves, 5 to 8 in
(12.5-20 cm) long, are pinnate, having 4 to 8 alternate,
elliptic-oblong to lanceolate, abruptly pointed, leaflets, somewhat
leathery, smooth, glossy, dark-green on the upper surface and
grayish-green beneath, and 2 to 3 in (5-7.5 cm) long. The tiny
petalless, greenish-white to yellowish flowers are borne in terminal
clusters to 30 in (75 cm) long. Showy fruits, in loose, pendent
clusters of 2 to 30 are usually strawberry-red, sometimes rose, pinkish
or amber, and some types tinged with green. Most are aromatic, oval,
heart-shaped or nearly round, about 1 in (2.5 cm) wide and 1 1/2 in (4
cm) long; have a thin, leathery, rough or minutely warty skin, flexible
and easily peeled when fresh. Immediately beneath the skin of some
varieties is a small amount of clear, delicious juice. The glossy,
succulent, thick, translucent-white to grayish or pinkish fleshy aril
which usually separates readily from the seed, suggests a large,
luscious grape. The flavor of the flesh is subacid and distinctive.
There is much variation in the size and form of the seed.
Normally,
it is oblong, up to 3/4 in (20 mm) long, hard, with a shiny, dark-brown
coat and is white internally. Through faulty pollination, many fruits
have shrunken, only partially developed seeds (called "chicken tongue")
and such fruits are prized because of the greater proportion of flesh.
In a few days, the fruit naturally dehydrates, the skin turns brown and
brittle and the flesh becomes dry, shriveled, dark-brown and
raisin-like, richer and somewhat musky in flavor. Because of the
firmness of the shell of the dried fruits, they came to be nicknamed
"lychee, or litchi, nuts" by the uninitiated and this erroneous name
has led to much misunderstanding of the nature of this highly desirable
fruit. It is definitely not a "nut", and the seed is inedible.
Origin and Distribution
The
lychee is native to low elevations of the provinces of Kwangtung and
Fukien in southern China, where it flourishes especially along rivers
and near the seacoast. It has a long and illustrious history having
been praised and pictured in Chinese literature from the earliest known
record in 1059 A.D. Cultivation spread over the years through
neighboring areas of southeastern Asia and offshore islands. Late in
the 17th Century, it was carried to Burma and, 100 years later, to
India. It arrived in the West Indies in 1775, was being planted in
greenhouses in England and France early in the 19th Century, and
Europeans took it to the East Indies. It reached Hawaii in 1873, and
Florida in 1883, and was conveyed from Florida to California in 1897.
It first fruited at Santa Barbara in 1914. In the 1920's, China's
annual crop was 30 million lbs (13.6 million kg). In 1937 (before WW
II) the crop of Fukien Province alone was over 35 million lbs (16
million kg). In time, India became second to China in lychee
production, total plantings covering about 30,000 acres (12,500 ha).
There are also extensive plantings in Pakistan, Bangladesh, Burma,
former Indochina, Taiwan, Japan, the Philippines, Queensland,
Madagascar, Brazil and South Africa. Lychees are grown mostly in
dooryards from northern Queensland to New South Wales, but commercial
orchards have been established in the past 20 years, some consisting of
5,000 trees.
Madagascar began experimental refrigerated
shipments of lychees to France in 1960. It is recorded that there were
2 trees about 6 years old in Natal, South Africa, in 1875. Others were
introduced from Mauritius in 1876. Layers from these latter trees were
distributed by the Durban Botanical Gardens and lychee-growing expanded
steadily until in 1947 there were 5,000 bearing trees on one estate and
5,000 newly planted on another property, a total of 40,000 in all.
In
Hawaii, there are many dooryard trees but commercial plantings are
small. The fruit appears on local markets and small quantities are
exported to the mainland but the lychee is too undependable to be
classed as a crop of serious economic potential there. Rather, it is
regarded as a combination ornamental and fruit tree.
There are
only a few scattered trees in the West Indies and Central America apart
from some groves in Cuba, Honduras and Guatemala. In California, the
lychee will grow and fruit only in protected locations and the climate
is generally too dry for it. There are a few very old trees and one
small commercial grove. In the early 1960's, interest in this crop was
renewed and some new plantings were being made on irrigated land.
At
first it was believed that the lychee was not well suited to Florida
because of the lack of winter dormancy, exposing successive flushes of
tender new growth to the occasional periods of low temperature from
December to March. The earliest plantings at Sanford and Oviedo were
killed by severe freezes. A step forward came with the importation of
young lychee trees from Fukien, China, by the Rev. W.M. Brewster
between 1903 and 1906. This cultivar, the centuries-old 'Chen-Tze' or
'Royal Chen Purple', renamed 'Brewster' in Florida, from the northern
limit of the lychee-growing area in China, withstands light frost and
proved to be very successful in the Lake Placid area–the "Ridge"
section of Central Florida.
Layered trees were available from
Reasoner's Royal Palm Nurseries in the early 1920's, and the Reasoner's
and the U.S. Department of Agriculture made many new introductions for
trial. But there were no large plantings until an improved method of
propagation was developed by Col. William R. Grove who became
acquainted with the lychee during military service in the Orient,
retired from the Army, made his home at Laurel (14 miles south of
Sarasota, Florida) and was encouraged by knowledgeable Prof. G. Weidman
Groff, who had spent 20 years at Canton Christian College. Col. Grove
made arrangements to air-layer hundreds of branches on some of the old,
flourishing 'Brewster' trees in Sebring and Babson Park and thus
acquired the stock to establish his lychee grove. He planted the first
tree in 1938, and by 1940 was selling lychee plants and promoting the
lychee as a commercial crop. Many small orchards were planted from
Merritt's Island to Homestead and the Florida Lychee Growers'
Association was founded in 1952, especially to organize cooperative
marketing. The spelling "lychee" was officially adopted by the
association upon the strong recommendation of Professor Groff.
In
1960, over 6,000 lbs (2,720 kg) were shipped to New York, 4,000 lbs
(1,814 kg) to California, nearly 6,000 lbs (2,720 kg) to Canada, and
3,900 lbs (1, 769 kg) were consumed in Florida, though this was far
from a record year. The commercial lychee crop in Florida has
fluctuated with weather conditions, being affected not only by freezes
but also by drought and strong winds. Production was greatly reduced in
1959, to a lesser extent in 1963, fell drastically in 1965, reached a
high of 50,770 lbs (22,727 kg) in 1970, and a low of 7,200 lbs (3,273
kg) in 1974. Some growers lost up to 70% of their crop because of
severe cold in the winter of 1979-80. Of course, there are many bearing
trees in home gardens that are not represented in production figures.
The fruit from these trees may be merely for household consumption or
may be purchased at the site by Chinese grocers or restaurant
operators, or sold at roadside stands.
Though the Florida lychee
industry is small, mainly because of weather hazards, irregular bearing
and labor of hand-harvesting, it has attracted much attention to the
crop and has contributed to the dissemination of planting material to
other areas of the Western Hemisphere. Escalating land values will
probably limit the expansion of lychee plantings in this rapidly
developing state. Another limiting factor is that much land suitable
for lychee culture is already devoted to citrus groves.
Varieties
Professor
Groff, in his book, The lychee and the lungan, tells us that the
production of superior types of lychee is a matter of great family
pride and local rivalry in China, where the fruit is esteemed as no
other. In 1492, a list of 40 lychee varieties, mostly named for
families, was published in the Annals of Fukien. In the Kwang provinces
there were 22 types, 30 were listed in the Annals of Kwangtung, and 70
were tallied as varieties of Ling Nam. The Chinese claim that the
lychee is highly variable under different cultural and soil conditions.
Professor Groff concluded that one could catalog 40 or 50 varieties as
recognized in Kwangtung, but there were only 15 distinct, widely-known
and commercial varieties grown in that province, half of them marketed
in season in the City of Canton. Some of these are classed as
"mountain" types; the majority are "water types" (grown in low,
well-irrigated land). There is a special distinction between the kinds
of lychee that leak juice when the skin is broken and those that retain
the juice within the flesh. The latter are called "dry- and -clean" and
are highly prized. There is much variation in form (round, egg-shaped
or heart-shaped), skin color and texture, the fragrance and flavor and
even the color, of the flesh; and the amount of "rag" in the seed
cavity; and, of prime importance, the size and form of the seed.
The following are the 15 cultivars recognized by Professor Groff:
'No Mai Tsze',
or 'No mi ts 'z' (glutinous rice) is the leading variety in China;
large, red, "dry-and-clean"; seeds often small and shriveled. It is one
of the best for drying, and is late in season. It does best when
grafted onto the 'Mountain' lychee.
'Kwa Iuk'
or 'Kua lu' (hanging green) is a famous lychee; large, red with a green
tip and a typical green line; "dry-and-clean"; of outstanding flavor
and fragrance. It was, in olden times, a special fruit for presentation
to high officials and other persons in positions of honor. Professor
Groff was given a single fruit in a little red box!
'Kwai mi'
or 'Kuei Wei', (cinnamon flavor) which came to be called 'Mauritius' is
smaller, heart-shaped, with rough red skin tinged with green on the
shoulders and usually having a thin line running around the fruit. The
seed is small and the flesh very sweet and fragrant. The branches of
the tree curve upward at the tips and the leaflets curl inward from the
midrib.
'Hsiang li', or
'Heung lai' (fragrant lychee) is home by a tree with distinctive erect
habit having upward-pointing leaves. The fruit is small, very rough and
prickly, deep-red, with the smallest seeds of all, and the flesh is of
superior flavor and fragrance. It is late in season. Those grown in Sin
Hsing are better than those grown in other locations.
'Hsi Chio tsu',
or 'Sai kok tsz' (rhinoceros horn) is borne by a large-growing tree.
The fruit is large, rough, broad at the base and narrow at the apex;
has somewhat tough and fibrous, but fragrant, sweet, flesh. It ripens
early.
'Hak ip', or 'Hei
yeh', (black leaf) is borne by a densely-branched tree with large,
pointed, slightly curled, dark-green leaflets. The fruit is medium-red,
sometimes with green tinges, broad-shouldered, with thin, soft skin and
the flesh, occasionally pinkish, is crisp and sweet. This is rated as
"one of the best 'water' lychees."
'Fei tsu hsiao',
or 'Fi tsz siu' (imperial concubine's laugh, or smile) is large,
amber-colored, thin-skinned, with very sweet, very fragrant flesh.
Seeds vary from large to very small. It ripens early.
'T' ang po',
or 'T' ong pok' (pond embankment) is from a small-leaved tree. The
fruit is small, red, rough, with thin, juicy acid flesh and very little
rag. It is a very early variety.
'Sheung shu wai'
or'Shang hou huai', (President of a Board's embrace) is borne on a
small-leaved tree. The fruit is large, rounded, red, with many dark
spots. It has sweet flesh with little scent and the seed size is
variable. It is rather late in season.
'Ch'u ma lsu',
or 'Chu ma lsz' (China grass fiber) has distinctive, lush foliage. The
leaves are large, overlapping, with long petioles. The fruits are large
with prominent shoulders and rough skin, deep red inside. While very
fragrant, the flesh is of inferior flavor and clings to the seed which
varies from large to small.
'Ta tsao',
or 'Tai tso' (large crop) is widely grown around Canton; somewhat
egg-shaped; skin rough, bright-red with many small, dense dots; flesh
firm, crisp, sweet, faintly streaked with yellow near the large seed.
The juice leaks when the skin is broken. The fruit ripens early.
'Huai chih',
or 'Wai chi' (the Wai River lychee) has medium-sized, blunt leaves. The
fruit is round with medium-smooth skin, a rich red outside, pink
inside; and leaking juice. This is not a high class variety but the
most commonly grown, high yielding, and late in season.
'San yueh hung',
or 'Sam ut hung' (third month red), also called 'Ma yuen', 'Ma un',
'Tsao kuo', 'Tso kwo', 'Tsao li', or 'Tsoli' (early lychee) is grown
along dykes. The branches are brittle and break readily; the leaves are
long, pointed, and thick. The fruit is very large, with red, thick,
tough skin and thick, medium-sweet flesh with much rag. The seeds are
long but aborted. This variety is popular mainly because it comes into
season very early.
'Pai la li chih',
or 'Pak lap lai chi' (white wax lychee), also called 'Po le tzu', or
'Pak lik tsz (white fragrant plant), is large, pink, rough, with
pinkish, fibrous, not very sweet flesh and large seeds. It ripens very
late, after 'Huai chih'.
'Shan chi',
or 'Shan chih' (mountain lychee), also called 'Suan chih', or 'Sun chi'
(sour lychee) grows wild in the hills and is often planted as a
rootstock for better varieties. The tree is of erect habit with erect
twigs and large, pointed, short-petioled leaves. The fruit is
bright-red, elongated, very rough, with thin flesh, acid flavor and
large seed.
'T'im ngam',
or 'T'ien yeh' (sweet cliff) is a common variety of lychee which
Professor Groff reported to be quite widely grown in Kwantung, but not
really on a commercial basis.
In his book, The Litchi, Dr. Lal
Behari Singh wrote that Bihar is the center of lychee culture in India,
producing 33 selected varieties classified into 15 groups. His
extremely detailed descriptions of the 10 cultivars recommended for
large-scale cultivation I have abbreviated (with a few bracketed
additions from other sources):
'Early Seedless',
or 'Early Bedana'. Fruit 1 1/3 in (3.4 cm) long, heart-shaped to oval;
rough, red, with green interspaces; skin firm and leathery; flesh
[ivory] to white, soft, sweet; seed shrunken, like a dog's tooth. Of
good quality. The tree bears a moderate crop, early in season.
'Rose-scented'.
Fruit 1 1/4 in (3.2 cm) long; rounded-heart-shaped; slightly rough,
purplish-rose, slightly firm skin; flesh gray-white, soft, very sweet.
Seed round-ovate, fully developed. Of good quality. [Tree bears a
moderate crop] in midseason.
'Early Large Red'.
Fruit slightly more than 1 1/3 in (3.4 cm) long, usually obliquely
heart-shaped; crimson [to carmine], with green interspaces; very rough;
skin very firm and leathery, adhering slightly to the flesh. Flesh
grayish-white, firm, sweet and flavorful. Of very good quality. [Tree
is a moderate bearer], early in season.
'Dehra Dun',
[or 'Dehra Dhun']. Fruit less than 1 1/2 in (4 cm) long; obliquely
heart-shaped to conical; a blend of red and orange-red; skin rough,
leathery; flesh gray-white, soft, of good, sweet flavor. Seed often
shrunken, occasionally very small. Of good quality; midseason. [This is
grown extensively in Uttar Pradesh and is the most satisfactory lychee
in Pakistan.]
'Late Long Red',
or 'Muzaffarpur'. Fruit less than 1 1/2 in (4 cm) long; usually
oblong-conical; dark-red with greenish interspaces; skin rough, firm
and leathery, slightly adhering to the flesh; flesh grayish-white,
soft, of good, sweet flavor. Seed cylindrical, fully developed. Of good
quality. [Tree is a heavy bearer], late in season.
'Pyazi'.
Fruit 1 1/3 in (3.4 cm) long; oblong-conical to heart-shaped; a blend
of orange and orange-red, with yellowish-red, not very prominent,
tubercles. Skin leathery, adhering; flesh gray-white, firm, slightly
sweet, with flavor reminiscent of "boiled onion". Seed cylindrical,
fully developed. Of poor quality. Early in season.
'Extra Early Green'.
Fruit 1 1/4 in (3.2 cm) long; mostly heart-shaped, rarely rounded or
oblong; yellowish-red with green interspaces; skin slightly rough,
leathery, slightly adhering; flesh creamy-white, [firm, of good,
slightly acid flavor]; seed oblong, cylindrical or flat. Of indifferent
quality. Very early in season.
'Kalkattia',
['Calcuttia', or 'Calcutta']. Fruit 1 1/2 in (4 cm) long; oblong or
lopsided; rose-red with darker tubercles; skin very rough, leathery,
slightly adhering; flesh grayish ivory, firm, of very sweet, good
flavor. Seed oblong or concave. Of very good quality. [A heavy bearer;
withstands hot winds]. Very late in season.
'Gulabi'.
Fruit 1 1/3 in (3.4 cm) long; heart-shaped, oval or oblong; pink-red to
carmine with orange-red tubercles; skin very rough, leathery,
non-adherent; flesh gray-white, firm, of good subacid flavor; seed
oblong-cylindrical, fully developed. Of very good quality. Late in
season.
'Late Seedless',
or 'Late Bedana'. Fruit less than 1 3/8 in (3.65 cm) long; mainly
conical, rarely ovate; orange-red to carmine with blackish-brown
tubercles; skin rough, firm, non-adherent; flesh creamy-white, soft;
very sweet, of very good flavor except for slight bitterness near the
seed. Seed slightly spindle-shaped, or like a dog's tooth;
underdeveloped. Of very good quality. [Tree bears heavily. Withstands
hot winds.] Late in season.
There are numerous lychee orchards in the submontane region of the Punjab. The leading variety is:
'Panjore common'.
Fruit is large, heart-shaped, deep-orange to pink; skin is rough, very
thin, apt to split. Tree bears heavily and has the longest fruiting
season-for an entire month beginning near the end of May. Six other
varieties commonly grown there are: 'Rose-scented', 'Bhadwari',
'Seedless No. 1', 'Seedless No. 2', 'Dehra Dun', and 'Kalkattia'.
In
South Africa, only one variety is produced commercially. It is the
'Kwai Mi' but it is locally called 'Mauritius' because nearly all of
the trees are descendants of those brought in from that island. In
South Africa, the fruit is of medium size, nearly round but slightly
oval, reddish-brown. Flesh is firm, of good quality and usually
contains a medium-sized seed, but certain fruits with broad, flat
shoulders and shortened form tend to have "chicken-tongue" seeds.
There
have been many other introductions into South Africa from China and
India but most failed to survive. In 1928, 16 varieties from India were
planted at Lowe's Orchards, Southport, Natal, but the records were lost
and they remained unnamed. A Litchi Variety Orchard of 26 cultivars
from India, China, Taiwan and elsewhere was established at the
Subtropical Horticulture Research Station in Nelspruit. Tentative
classifications grouped these into 3 distinct types–'Kwai Mi'
['Mauritius'], 'Hak Ip' (of high quality and small seed but a shy
bearer in the Low-veld), and the 'Madras', a heavy bearer of choice
fruits, bright-red, very rough, and with large seeds, but very sweet,
luscious flesh.
The first lychee introduced into Hawaii was the
'Kwai Mi', as was the second introduction several years later. The high
quality of this variety (sometimes locally called 'Charlie Long')
caused the lychee to become extremely popular and widely planted. The
Hawaiian Agricultural Experiment Station imported 3 'Brewster' trees in
1907, and various efforts were made to bring other types from China but
not all survived. A total of 16 varieties became well established in
Hawaii, including 'Hak Ip' which has become second to 'Kwai Mi' in
importance.
In
1942, the Agricultural Experiment Station set out a collection of 500
seedlings of 'Kwai Mi', 'Hak Ip' and 'Brewster' with a view to
selecting the trees showing the best performance. One tree of
outstanding character (a seedling of 'Hak Ip') was first designated
H.A.E.S. Selection 1-18-3 and was given the name 'Groff' in 1953. It is
a consistent bearer, late in season. The fruit is of medium size, dark
rose-red with green or yellowish tinges on the apex of each tubercle.
The flesh is white and firm; there is no leaking juice; the flavor is
excellent, sweet and subacid; most of the fruits have abortive,
"chicken-tongue" seeds and, accordingly have 20% more flesh than if the
seeds were fully developed.
'No Mai Tsze'
has been growing in Hawaii for over 40 years but has produced very few
fruits. 'Pat Po Heung' (eight precious fragrances), erroneously called
'Pat Po Hung' (eight precious red), somewhat resembles 'No Mai Tsze'
but is smaller; the skin is purplish-red, thin and pliable; the juice
leaks when the skin is broken; the flesh is soft, juicy, sweet even
when slightly unripe; the seed varies from medium to large. The tree is
slow-growing and of weak, spreading habit; it bears well in Hawaii.
Nevertheless, it is not commonly planted.
'Kaimana',
or 'Poamoho', an open-pollinated seedling of 'Hak Ip', developed by Dr.
R.A. Hamilton at the Poamoho Experiment Station of the University of
Hawaii, was released in 1982. The fruit resembled 'Kwai Mi' but is
twice as large, deep-red, of high quality, and the tree is a regular
bearer.
'Brewster' is
large, conical or wedge-shaped, red, with soft flesh, more acid than
that of 'Kwai mi', and the seeds are very often fully formed and large.
The leaflets are flat with slightly recurved margins and taper to a
sharp point.
There were many other introductions of seeds,
seedlings, cuttings or air-layers into the United States, from 1902 to
1924, mostly from China; also from India and Hawaii, and a few from
Java, Cuba, and Trinidad; and these were distributed to experimenters
in Florida and California, and some to botanical gardens in other
states, and to Cuba, Puerto Rico, Panama, Honduras, Costa Rica and
Brazil. Many were killed by cold weather in California and Florida.
In
1908, the United States Department of Agriculture brought in 27 plants
of 'Kwai mi'. At the same time, 20 plants of 'Hak Ip' were imported and
these were sent to George B. Cellon in Miami in 1918. A tree of the
'Bedana' was introduced from India in 1913. In 1920, Professor Groff
obtained seedlings of 'Shan Chi' (mountain lychee) from Kwantung
Province, together with air-layers of 'Sheung shu wai', 'No mai ts 'z',
and 'T' im ngam' (sweet cliff). The latter was found to bear more
regularly than 'Brewster' but exhibited nutritional deficiencies in
limestone soil.
Most of the various plants and rooted cuttings
from them were distributed for trial; the rest were kept in U.S.
Department of Agriculture greenhouses in Maryland.
'Bengal'–In
1929, the U.S. Department of Agriculture received a small lychee plant,
supposedly a seedling of 'Rose-scented', from Calcutta. It was planted
at the Plant Introduction Station in Miami and began bearing in 1940.
The fruits resembled 'Brewster' but were more elongated, were home in
large clusters, and the flesh was firm, not leaking juice when peeled.
All the fruits had fully developed seeds but smaller in proportion to
flesh than those of 'Brewster'. The habit of the tree is more spreading
than that of 'Brewster'; it has larger, more leathery, darker green
leave's, and the bark is smoother and paler. The original tree and its
air-layered progeny have shown no chlorosis on limestone in contrast to
'Brewster' trees growing nearby.
'Peerless',
believed to be a seedling of 'Brewster', originated at the Royal Palm
Nursery at Oneco; was transplanted to the T.R. Palmer Estate in
Belleair where C.E. Ware noticed from 1936 to 1938 that it bore fruit
of larger size, brighter color and higher percentage of abortive seed
than 'Brewster'. In 1938, Ware air-layered and removed 200 branches,
purchased the tree and moved it to his property in Clearwater. It
resumed fruiting in 1940 and annual crops recorded to 1956 showed good
productivity-averaging 383.4 lbs (174 kg) per year, and the rate of
abortive seeds ranged from 62% to 85%. The 200 air-layers were planted
out by Ware in 1942 and began bearing in 1946. Most of the fruits had
fully developed seeds but the rate of abortive seeds increased year by
year and in 1950 was 61% to 70%. The cultivar was named with the
approval of the Florida Lychee Growers Association. Two seedling
selections by Col. Grove, 'Yellow Red' and 'Late Globe', Prof. Groff
believed to be natural hybrids of 'Brewster' ´ 'Mountain'.
In
northern Queensland, 'Kwai Mi' is the earliest cultivar grown, and
about 10% of the fruits have "chicken tongue" seeds. 'Brewster' bears
in mid-season and is important though the seed is nearly always fully
formed and large. 'Hak Ip' is also midseason and large-seeded there.
'Bedana' is grown only in home gardens and the fruits have large seeds
unlike the usual "chicken tongue" seeds of the fruits of this cultivar
borne in India.
'Wai Chi'
is late in season (December), has small, round fruits, basically yellow
overlaid with red; the seed is small and oval. The tree is very compact
with upright branches, and prefers a cooler climate than that of
coastal north Queensland where it does not fruit heavily. The leaflets
are concave like those of 'Kwai Mi'.
A very similar, perhaps
identical, cultivar called 'Hong Kong' is grown in South Queensland.
'No Mai' bears poorly in Queensland and seems better adapted to cooler
areas.
Blooming and Pollination
There
are 3 types of flowers appearing in irregular sequence or, at times,
simultaneously, in the lychee inflorescence: a) male; b) hermaphrodite,
fruiting as female (about 30% of the total); c) hermaphrodite fruiting
as male. The latter tend to possess the most viable pollen. Many of the
flowers have defective pollen and this fact probably is the main cause
of the abortive seeds and also the common problem of shedding of young
fruits. The flowers require transfer of pollen by insects.
In
India, L.B. Singh recorded 11 species of bees, flies, wasps and other
insects as visiting lychee flowers for nectar. But honeybees, mostly Apis cerana indica, A. dorsata and A. florea, constitute 78% of the lychee-pollinating insects and they work the flowers for pollen and nectar from sunrise to sundown. A. cerana is the only hive bee and is essential in commercial orchards for maximum fruit production.
A
6-week survey in Florida revealed 27 species of lychee-flower visitors,
representing 6 different insect Orders. Most abundant, morning and
afternoon, was the secondary screw-worm fly (Callitroga macellaria), an undesirable pest. Next was the imported honeybee (Apis mellifera)
seeking nectar daily but only during the morning and apparently not
interested in the pollen. No wild bees were seen on the lychee flowers,
though wild bees were found in large numbers collecting pollen in an
adjacent fruit-tree planting a few weeks later. Third in order, but not
abundant, was the soldier beetle (Chauliognathus marginatus).
The rest of the insect visitors were present only in insignificant
number. Maintenance of bee hives in Florida lychee groves is necessary
to enhance fruit set and development. The fruits mature 2 months after
flowering.
In India and Hawaii, there has been some interest in
possible cross-breeding of the lychee and pollen storage tests have
been conducted. Lychee pollen has remained viable at room temperature
for 10 to 30 days in petri dishes; for 3 to 5 months in desiccators; 15
months at 32° F (0° C) and 25% relative humidity in
desiccators; and 31 months under deep-freeze, -9.4° F (-23° C).
There is considerable variation in the germination rates of pollen from
different cultivars. In India, 'Rose Scented' has shown mean viability
of 61.99% compared with 42.52% in 'Khattl'.
Climate
Groff
provided a clear view of the climatic requirements of the lychee. He
said that it thrives best in regions "not subject to heavy frost but
cool and dry enough in the winter months to provide a period of rest."
In China and India, it is grown between 15° and 30° N. "The
Canton delta ... is crossed by the Tropic of Cancer and is a
subtropical area of considerable range in climate. Great fluctuations
of temperature are common throughout the fall and winter months. In the
winter sudden rises of temperature will at times cause the lychee ...
to flush forth ... new growth. This new growth is seldom subject to a
freeze about Canton. On the higher elevations of the mountain regions
which are subject to frost the lychee is seldom grown . . . The more
hardy mountainous types of the lychee are very sour and those grown
near salt water are said to be likewise. The lychee thrives best on the
lower plains where the summer months are hot and wet and the winter
months are dry and cool."
Heavy frosts will kill young trees but
mature trees can withstand light frosts. Cold tolerance of the lychee
is intermediate between that of the sweet orange on one hand and mango
and avocado on the other. Location, land slope, and proximity to bodies
of water can make a great difference in degree of damage by freezing
weather. In the severe low temperature crisis during the winter of
1957-58, the effects ranged from minimal to total throughout central
and southern Florida. A grove of 12-to 14-year-old trees south of
Sanford was killed back nearly to the ground; on Merritt Island trees
of the same age were virtually undamaged, while a commercial mango
planting was totally destroyed. L.B. Singh resists the common belief
that the lychee needs winter cold spells that provide periods of
temperature between 30° and 40° F (-1.11° and 4.44° C)
because it does well in Mauritius where the temperature is never below
40° F (-1.11° C). However, lychee trees in Panama, Jamaica, and
other tropical areas set fruit only occasionally or not at all.
Heavy
rain or fog during the flowering period is detrimental, as are hot,
dry, strong winds which cause shedding of flowers, also splitting of
the fruit skin. Splitting occurs, too, during spells of alternating
rain and hot, dry periods, especially on the sunny side of the tree.
Spraying with Ethephon at 10 ppm reduced splitting in 'Early Large Red'
in experiments in Nepal.
Soil
The
lychee grows well on a wide range of soils. In China it is cultivated
in sandy or clayey loam, "river mud", moist sandy clay, and even heavy
clay. The pH should be between 6 and 7. If the soil is deficient in
lime, this must be added. However, in an early experiment in a
greenhouse in Washington, D.C., seedlings planted in acid soil showed
superior growth and the roots had many nodules filled with mycorrhizal
fungi. This caused some to speculate that inoculation might be
desirable. Later, in Florida, profuse nodulation was observed on roots
of lychee seedlings that had not been inoculated but merely grown in
pots of sphagnum moss and given a well-balanced nutrient solution.
The
lychee attains maximum growth and productivity on deep alluvial loam
but flourishes in extreme southern Florida on oolitic limestone
providing it is put in an adequate hole and irrigated in dry seasons.
The
Chinese often plant the lychee on the banks of ponds and streams. In
low, wet land, they dig ditches 10 to 15 ft (3-4.5 m) wide and 30 to 40
ft (9-12 m) apart, using the excavated soil to form raised beds on
which they plant lychee trees, so that they have perfect drainage but
the soil is always moist. Though the lychee has a high water
requirement, it cannot stand water-logging. The water table should be
at least 4 to 6 ft (1.2-1.8 m) below the surface and the underground
water should be moving inasmuch as stagnant water induces root rot. The
lychee can stand occasionally brief flooding better than citrus. It
will not thrive under saline conditions.
Propagation
Lychees
do not reproduce faithfully from seed, and the choicest have abortive,
not viable, seed. Furthermore, lychee seeds remain viable only 4 to 5
days, and seedling trees will not bear until they are 5 to 12, or even
25, years old. For these reasons, seeds are planted mostly for
selection and breeding purposes or for rootstock.
Attempts to
grow the lychee from cuttings have been generally discouraging, though
80% success has been claimed with spring cuttings in full sun, under
constant mist and given weekly liquid nutrients. Ground-layering has
been practiced to some extent. In China, air-layering (marcotting, or
gootee) is the most popular means of propagation and has been practiced
for ages. By their method, a branch of a chosen tree is girdled,
allowed to callus for 1 to 2 days and then is enclosed in a ball of
sticky mud mixed with chopped straw or dry leaves and wrapped with
burlap. With frequent watering, roots develop in the mud and, in about
100 days, the branch is cut off, the ball of earth is increased to
about 12 in (30 cm) in width, and the air-layer is kept in a sheltered
nursery for a little over a year, then gradually exposed to full sun
before it is set out in the orchard. Some air-layers are planted in
large clay pots and grown as ornamentals.
The Chinese method of
air-layering has many variations. In fact, 92 modifications have been
recorded and experimented with in Hawaii. Inarching is also an ancient
custom, selected cultivars being joined to 'Mountain' lychee rootstock.
In
order to make air-layering less labor-intensive, to eliminate the
watering, and also to produce portable, shippable layers, Colonel
Grove, after much experimentation, developed the technique of packing
the girdle with wet sphagnum moss and soil, wrapping it in
moisture-proof clear plastic that permits exchange of air and gasses,
and tightly securing it above and below. In about 6 weeks, sufficient
roots are formed to permit detaching of the layer, removal of the
plastic wrap, and planting in soil in nursery containers. It is
possible to air-layer branches up to 4 in (10 cm) thick, and to take
200 to 300 layers from a large tree.
Studies in Mexico have led
to the conclusion that, for maximum root formation, branches to be
air-layered should not be less than 5/8 in (15 mm) in diameter, and, to
avoid undue defoliation of the parent tree, should not exceed 3/4 in
(20 mm). The branches, of any age, around the periphery of the canopy
and exposed to the sun, make better air-layers with greater root
development than branches taken from shaded positions on the tree. The
application of growth regulators, at various rates, has shown no
significant effect on root development in the Mexican experiments. In
India, certain of the various auxins tried stimulated root formation,
forced early maturity of the layers, but contributed to high mortality.
South African horticulturists believe that tying the branch up so that
it is nearly vertical induces vigorous rooting.
The
new trees, with about half of the top trimmed off and supported by
stakes, are kept in a shade house for 6 weeks before setting out.
Improvements in Colonel Grove's system later included the use of
constant mist in the shade house. Also, it was found that birds pecked
at the young roots showing through the transparent wrapping, made holes
in the plastic and caused dehydration. It became necessary to shield
the air-layers with a cylinder of newspaper or aluminum foil. As time
went on, some people switched to foil in place of plastic for wrapping
the air-layers.
The air-layered trees will fruit in 2 to 5 years
after planting, Professor Groff said that a lychee tree is not in its
prime until it is 20 to 40 years old; will continue bearing a good crop
for 100 years or longer. One disadvantage of air-layering is that the
resultant trees have weak root systems. In China, a crude method of
cleft-grafting has long been employed for special purposes, but,
generally speaking, the lychee has been considered very difficult to
graft. Bark, tongue, cleft, and side-veneer grafting, also chip-and
shield-budding, have been tried by various experimenters in Florida,
Hawaii, South Africa and elsewhere with varing degrees of success. The
lychee is peculiar in that the entire cambium is active only during the
earliest phases of secondary growth. The use of very young rootstocks,
only 1/4 in (6 mm) in diameter and wrapping the union with strips of
vinyl plastic film, have given good results. A 70% success rate has
been achieved in splice-grafting in South Africa. Hardened-off, not
terminal, wood of young branches 1/4 in (6 mm) thick is first ringed
and the bark-ring removed. After a delay of 21 days, the branch is cut
off at the ring, defoliated but leaving the base of each petiole, then
a slanting cut is made in the rootstock 1 ft (30 cm) above the soil, at
the point where it matches the thickness of the graftwood (scion), and
retaining as many leaves as possible. The cut is trimmed to a perfectly
smooth surface 1 in (2.5 cm) long; the scion is then trimmed to 4 in
(10 cm) long, making a slanting cut to match that on the rootstock. The
scion should have 2 slightly swollen buds. After joining the scion and
the rootstock, the union is wrapped with plastic grafting tape and the
scion is completely covered with grafting strips to prevent
dehydration. In 6 weeks the buds begin to swell, and the plastic is
slit just above the bud to permit sprouting. When the new growth has
hardened off, all the grafting tape is removed. The grafting is
performed in a moist, warm atmosphere. The grafted plants are
maintained in containers for 2 years or more before planting out, and
they develop strong taproots.
In India, a more recent
development is propagation by stooling, which has been found "simpler,
quicker and more economical" there than air-layering. First, air-layers
from superior trees are planted 4 ft (1.2 m) apart in "stool beds"
where enriched holes have been prepared and left open for 2 weeks.
Fertilizer is applied when planting (at the beginning of September) and
the air-layers are well established by mid-October and putting out new
flushes of growth in November. Fertilizer is applied again in
February-March and June-July. Shallow cultivation is performed to keep
the plot weed-free. At the end of 2 1/2 years, in mid-February, the
plants are cut back to 10 in (25 cm) from the ground. New shoots from
the trunk are allowed to grow for 4 months. In mid-June, a ring of bark
is removed from all shoots except one on each plant and lanolin paste
containing IBA (2,500 ppm) is applied to the upper portion of the
ringed area. Ten days later, earth is heaped up to cover 4 to 6 in
(10-15 cm) of the stem above the ring. This causes the shoots to root
profusely in 2 months. The rooted shoots are separated from the plant
and are immediately planted in nursery beds or pots. Those which do not
wilt in 3 weeks are judged suitable for setting out in the field. The
earth around the parent plants is leveled and the process of
fertilization, cultivation, ringing and earthing-up and harvesting of
stools is repeated over and over for years until the parent plants have
lost their vitality. It is reported that the transplanted shoots have a
survival rate of 81-82% as compared with 40% to 50% in air-layers.
Culture
Spacing:
For a permanent orchard, the trees are best spaced 40 ft (12 m) apart
each way. In India, a 30 ft spacing is considered adequate, probably
because the drier climate limits the overall growth. Portions of the
tree shaded by other trees will not bear fruit. For maximum
productivity, there must be full exposure to light on all sides.
In
the Cook Islands, the trees are planted on a 40 x 20 ft (12 x 6 m)
spacing–56 trees per acre (134 per ha)–but in the 15th
year, the plantation is thinned to 40 x 40 ft (12 x l2 m).
Wind protection:
Young trees benefit greatly by wind protection. This can be provided by
placing stakes around each small tree and stretching cloth around them
as a windscreen. In very windy locations, the entire plantation may be
protected by trees planted as windbreaks but these should not be so
close as to shade the lychees. The lychee tree is structurally highly
wind-resistant, having withstood typhoons, but shelter may be needed to
safeguard the crop. During dry, hot months, lychee trees of any age
will benefit from overhead sprinkling; they are seriously retarded by
water stress.
Fertilization
Newly planted trees must be watered but not fertilized beyond the
enrichment of the hole well in advance of planting. In China, lychee
trees are fertilized only twice a year and only organic material is
used, principally night soil, sometimes with the addition of soybean or
peanut residue after oil extraction, or mud from canals and fish ponds.
There is no great emphasis on fertilization in India. It has been
established that a harvest of 1,000 lbs (454.5 kg) removes
approximately 3 lbs (1,361 g) K2O, 1 lb (454 g) P2O5, 1 lb (454 g) N,
3/4 lb (340 g) CaO, and 1/2 lb (228 g) MgO from the soil. It is judged,
therefore, that applications of potash, phosphate, lime and magnesium
should be made to restore these elements.
Fertilizer experiments
on fine sand in central Florida have shown that medium rates of N
(either sulfate of ammonia or ammonium nitrate), P2O5, K2O, and MgO,
together with one application of dolomite limestone at 2 tons/acre (4.8
tons/ha) are beneficial in counteracting chlorosis and promoting
growth, flowering and fruit-set and reducing early fruit shedding.
Excessive use of nitrogen suppresses growth and interferes with the
uptake of other nutrients. If vegetative dormancy is to be encouraged
in bearing trees, fertilizer should be withheld in fall and early
winter.
In limestone soil, it may be necessary to spread
chelated iron 2 or 3 times a year to avoid chlorosis. Zinc deficiency
is evidenced by bronzing of the leaves. It is corrected by a foliar
spray of 8 lbs (3.5 kg) zinc sulphate and 4 lbs (1.8 kg) hydrated lime
in 48 qts (45 liters) of water. Because of the very shallow root system
of the lychee, a surface mulch is very beneficial in hot weather.
Pruning
Ordinarily, the tree is not pruned after the judicious shaping of the
young plant, because the clipping off of a branch tip with each cluster
of fruits is sufficient to promote new growth for the next crop. Severe
pruning of old trees may be done to increase fruit size and yield for
at least a few years.
Girdling
The Indian farmer may girdle the
branches or trunk of his lychee trees in September to enhance flowering
and fruiting. Tests on 'Brewster' in Hawaii confirmed the much higher
yield obtained from branches girdled in September. Girdling of trees
that begin to flush in October and November is ineffective. Similar
trials in Florida showed increased yield of trees that had poor crops
the previous year, but there was no significant increase in trees that
had been heavy bearers. Furthermore, many branches were weakened or
killed by girdling. Repeated girdling as a regular practice would
probably seriously interfere with overall growth and productivity.
Indian
horticulturists warn that girdling in alternate years, or girdling just
half of the tree, may be preferable to annual girdling and that, in any
case, heavy fertilization and irrigation should precede girdling. Fall
spraying of growth inhibitors has not been found to increase yields.
Harvesting
For
home use or for local markets, lychees are harvested when fully
colored; for shipment, when only partly colored. The final swelling of
the fruit causes the protuberances on the skin to be less crowded and
to slightly flatten out, thus an experienced picker will recognize the
stage of full maturity. The fruits are rarely picked singly except for
immediate eating out-of-hand, because the stem does not normally detach
without breaking the skin and that causes the fruit to spoil quickly.
The clusters are usually clipped with a portion of stem and a few
leaves attached to prolong freshness. Individual fruits are later
clipped from the cluster leaving a stub of stem attached. Harvesting
may need to be done every 3 to 4 days over a period of 3-4 weeks. It is
never done right after rain, as the wet fruit is very perishable. The
lychee tree is not very suitable for the use of ladders. High clusters
are usually harvested by metal or bamboo pruning poles. A worker can
harvest 55 lbs (25 kg) of fruits per hour.
Yield
The
yield varies with the cultivar, age, weather, presence of pollinators,
and cultural practices. In India, a 5-year-old tree may produce 500
fruits, a 20-year-old tree 4,000 to 5,000 fruits–160 to 330 lbs
(72.5-149.6 kg). Exceptional trees have borne 1,000 lbs (455 kg) of
fruit per year. One tree in Florida has borne 1,200 lbs (544 kg). In
China, there are reports of 1,500 lb crops (680 kg). In South Africa,
trees 25 years old have averaged 600 lbs (272 kg) each in good years;
and an average yield per acre is approximately 10,000 lbs annually
(roughly equivalent to 10,000 kg per hectare).
Keeping Quality, Storage and Shipping
Freshly
picked lychees keep their color and quality only 3 to 5 days at room
temperature. If pre-treated with 0.5% copper sulphate solution and kept
in perforated polyethylene bags, they will remain fresh somewhat longer.
Fresh
fruits, picked individually by snapping the stems and later de-stemmed
during grading, and packed in shallow, ventilated cartons with
shredded-paper cushioning, have been successfully shipped by air from
Florida to markets throughout the United States and also to Canada. In
South Africa, freshly picked lychees have been placed on trays in
ventilated sheds, dusted with sulphur and left overnight, and then
allowed to "wilt" in lugs for 24 to 48 hours to permit any infested or
injured fruits to become conspicuous before grading and packing. It is
said that fruits so treated retain their fresh color and are unaffected
by fungi or pests for several weeks.
In China and India, lychees
are packed in baskets or crates lined with leaves or other cushioning.
The clusters or loose fruits are best packed in trays with protective
sheets between the layers and no more than 5 single layers or 3 double
layers are joined together. The pack should not be too tight.
Containers for stacked trays or fruits not so arranged, must be fairly
shallow to avoid too much weight and crushing. Spoilage may be retarded
by moistening the fruits with a salt solution.
In the Cook
Islands, the fruits are removed from the clusters, dipped in Benlate to
control fungal growth, dried on racks, then packed in cartons for
shipment to New Zealand. South African shippers immerse the fruits for
10 minutes in a suspension of 0.375 dicloran 50% wp plus 0.625 g
benomyl 50% wp per liter of water warmed to 125.6º F (52º C).
Tests at CSIRO, Div. of Food Research, New South Wales, Australia, in
1982, showed good color retention, retardation of weight loss and
fungal spoilage in lychees dipped in hot benomyl 0.05% at 125.6º F
(52º C) for two minutes and packed in trays with PVC "skrink" film
covering. The chemical treatment had not yet been approved by health
authorities.
Lychee clusters shipped to France by air from
Madagascar have arrived in fresh condition when packed 13 lbs (6 kg) to
the carton and cushioned with leaves of the traveler's tree (Ravenala
madagascariensis Sonn.).
Boat shipment requires hydrocooling at
the plantation at 32º-35.6º F (0º-2º C), packing in
sealed polyethylene bags, storing and conveying to the port at -4º
to -13º F (-20º--25º C) and shipping at 32º to
35.6º F (0º-2º C).
In Florida, fresh lychees in
sealed, heavy-gauge polyethylene bags keep their color for 7 days in
storage or transit at 35º to 50º F (1.67º-10º C).
Each bag should contain no more than 15 lbs (6.8 kg) of fruit.
Lychees
placed in polyethylene bags with moss, leaves, paper shavings or cotton
packing have retained fresh color and quality for 2 weeks in storage at
45º F (7.22º C); for a month at 40º F (4.44º C). At
32º to 35º F(0º-1.67º C) and 85% to 90% relative
humidity, untreated lychees, can be stored for 10 weeks; the skin will
turn brown but the flesh will be virtually in fresh condition but
sweeter.
Frozen, peeled or unpeeled, lychees in moisture-vapor-proof containers keep for 2 years.
Plate XXXIII: LYCHEE, Litchi chinensis: dried
Drying of Lychees
Lychees
dehydrate naturally. The skin loses its original color, becomes
cinnamon-brown, and turns brittle. The flesh turns dark-brown to nearly
black as it shrivels and becomes very much like a raisin. The skin of
'Kwai Mi' becomes very tough when dried; that of 'Madras' less so. The
fruits will dry perfectly if clusters are merely hung in a closed,
air-conditioned room.
In China, lychees are preferably dried in
the sun on hanging wire trays and brought inside at night and during
showers. Some are dried by means of brick stoves during humid weather.
When
exports of dried fruits from China to the United States were suspended,
India welcomed the opportunity to supply the market. Experimental
drying involved preliminary disinfection by immersing the fruits in
0.5% copper sulphate solution for 2 minutes. Sun-drying on coir-mesh
trays took 15 days and the results were good except that thin-skinned
fruits tended to crack. It was found that shade-drying for 2 days
before full exposure to the sun prevented cracking.
Electric-oven
drying of single layers arranged in tiers, at 122º to 140º F
(50º-65º C), requires only 4 days. Hot-air-blast at 160º
F(70º C) dries seedless fruits in 48 hours. Fire-oven and
vacuum-oven drying were found unsatisfactory. Florida researchers have
demonstrated the feasibility of drying untreated lychees at 120º F
(48.8º C) with free-stream air flow rates above 35 CMF/f2. Drying
at higher temperatures gave the fruits a bitter flavor.
The best
quality and light color of flesh instead of dark-brown is achieved by
first blanching in boiling water for 5 minutes, immersing in a solution
of 2% potassium metabisulphite for 48 hours, and dipping in citric acid
prior to drying.
Dried fruits can be stored in tins at room temperature for about a year with no change in texture or flavor.
Pests
In most areas where lychees are grown, the most serious foliage pest is the erinose, or leaf-curl, mite, Aceria litchii,
which attacks the new growth causing hairy, blister-like galls on the
upperside of the leaves, thickening, wrinkling and distorting them, and
brown, felt-like wool on the underside. The mite apparently came to
Florida on plants from Hawaii in 1953 but has been effectively
eradicated. A leaf-webber, Dudua aprobola, attacks the new growth of all lychee trees in the Punjab.
The most destructive enemy of the lychee in China is a stinkbug (Tessaratoma papillosa)
with bright-red markings. It sucks the sap from young twigs and they
often die; at least there is a high rate of fruit-shedding. This pest
is combatted by shaking the trees in winter, collecting the bugs and
dropping them into kerosene. Without such efforts, it works havoc. A
stinkbug (Banasa lenticularis) has been found on lychee foliage in Florida. The leaf-eating false-unicorn caterpillar (Schizura ipomeae), which is parasitized by a tachinid fly (Thorocera floridensis) feeds on the leaves. The foliage is sometimes infested with red spider mites (Paratetranychus hawaiiensis). The citrus aphid (Toxoptera aurantii) preys on flush foliage. Two leaf rollers, Argyroploce leucaspis, and A. aprobola, are active on lychee trees in India. Thrips (Dolicothrips idicus) attack the foliage and Megalurothrips (Taeniothrips) distalis and Lymantria mathura damage the flowers.
A twig-pruner, Hypermallus villosus, has damaged lychee trees in Florida and a twig borer, Proteoteras implicata, has killed twigs of new growth on Florida lychees. The larvae of a native leaf beetle, Exema nodulosa,
has been found puncturing and girdling lychee branchlets 1/8 to 1/4 in
(3-6 mm) thick. Ambrosia beetles bore into the stems of young trees and
fungi enter through their holes. A shoot-borer, Chlumetia transversa, is found on lychee trees all over India. Two bark-boring caterpillars, Indarbela quadrinotata and I. tetraonis, bore rings around the trunk underneath the bark of older trees. The larvae of a small moth, Acrocerops cramerella,
eat developing seeds and the pith of young twigs. A small parasitic
wasp helps to control this predator, as does the sanitary practice of
burning the fallen lychee leaves.
The aphid (Aphis spiraecola) occurs on young plants in shaded nurseries, as does the armored scale, or lychee bark scale, Pseudaulacaspis major, and white peach scale, P. pentagona. The Florida red scale, Chrysomphalus aonidum, has been seen on lychee trees, also the banana-shaped scale, Coccus acutissimus, and green-shield scale, Pulvinaria psidii. The latter is the second most serious pest in Florida. Others are the six-spotted mite, Eotetranychus sexmaculatus, the leaf-footed bug, Leptoglossus phyllopus,
and less troublesome creatures such as the several species of
Scarabaeidae (related to June bugs) which attack leaves and flower buds.
In South Africa, the parasitic nematode Hemicriconemoides mangiferae and Xiphinema brevicolle cause die-back, decline and ultimately death of lychee trees, sometimes devastating orchards. The root-knot nematode, Meloidogyne javanica, also attacks the lychee in South Africa but is less prevalent.
In Florida, the southern green stinkbug, Nezara viridula, and the larvae of the cotton square borer, Strymon metinus, attack the fruit. Seed-feeding Lepidoptera, especially Cryptophlebia ombrodelta and Lobesia
sp. cause much fruit damage and falling in northern Queensland.
Carbaryl sprays considerably reduce the losses. In South Africa, a
moth, Argyroploce peltastica,
lays eggs on the surface of the fruit and the larvae may penetrate weak
areas of the skin and infest the flesh. The fruit flies, Ceratites capitata and Pterandrus rosa make minute holes and cracks in the skin and cause internal decay.
These
pests are so detrimental that growers have adopted the practice of
enclosing bunches of clusters (with most of the leaves removed) in bags
made of "wet-strength" paper or unbleached calico 6 to 8 weeks before
harvest-time. The Caribbean fruit fly, Anastrepha suspensa, has attacked lychee fruits in Florida.
Birds,
bats and bees damage ripe fruits on the trees in China and sometimes a
stilt house is built beside a choice lychee tree for a watchman to keep
guard and ward off these predators, or a large net may be thrown over
the tree. In Florida, birds, squirrels, raccoons and rats are prime
enemies. Birds have been repelled by hanging on the branches thin
metallic ribbons which move, gleam and rattle in the wind.
Grasshoppers, crickets, and katydids may, at times, feed heavily on the
foliage.
Diseases
Few
diseases have been reported from any lychee-growing locality. The
glossy leaves are very resistant to fungi. In Florida, lychee trees are
occasionally subject to green scurf, or algal leaf spot (Cephaleuros virescens), leaf blight (Gleosporium sp.), die-back, caused by Phomopsis sp., and mushroom root rot (Clitocybe tabescens)
which is most likely to attack lychee trees planted where oak trees
formerly stood. Old oak roots and stumps have been found thoroughly
infected with the fungus.
In India, leaf spot caused by Pestalotia pauciseta may be prevalent in December and can be controlled by lime-sulphur sprays. Leaf spots caused by Botryodiplodia theobromae and Colletotrichum gloeosporioides, which begin at the tip of the leaflet, were first noticed in India in 1962.
Lichens and algae commonly grow on the trunks and branches of lychee trees.
The
main post-harvest problem is spoilage by the yeast-like organism, which
is quick to attack warm, moist fruits. It is important to keep the
fruits dry and cool, with good circulation of air. When conditions
favor rotting, dusting with fungicide will be necessary.
Fig. 73: Peeled, seeded, lychees (Litchi chinensis) are canned in sirup in the Orient and exported to the United States and other countries.
Food Uses
Lychees are most relished fresh, out-of-hand. Peeled and pitted, they are commonly added to fruit cups and fruit salads.
Lychees
stuffed with cottage cheese are served as salad topped with dressing
and pecans. Or the fruit may be stuffed with a blend of cream cheese
and mayonnaise, or stuffed with pecan meats, and garnished with whipped
cream.
Sliced lychees, congealed in lime gelatin, are served on
lettuce with whipped cream or mayonnaise. The fruits may be layered
with pistachio ice cream and whipped cream in parfait glasses, as
dessert. Halved lychees have been placed on top of ham during the last
hour of baking, or grilled on top of steak.
Pureed lychees are
added to ice cream mix. Sherbet is made by extracting the juice from
fresh, seeded lychees and adding it to a mixture of prepared plain
gelatin, hot milk, light cream, sugar and a little lemon juice, and
freezing.
Peeled, seeded lychees are canned in sugar sirup in
India and China and have been exported from China for many years.
Browning, or pink discoloration, of the flesh is prevented by the
addition of 4% tartaric acid solution, or by using 30º Brix sirup
containing 0.1% to 0.15% citric acid to achieve a pH of about 4.5,
processing for a maximum of 10 minutes in boiling water, and chilling
immediately.
| Food
Value Per
100 g of Edible Portion* |
| Fresh | Dried | | Calories | 63-64 | 277 | | Moisture | 81.9-84.83% | 17.90-22.3% | | Protein | 0.68-1.0 g | 2.90-3.8 g | | Fat | 0.3-0.58 g | 0.20-1.2 g | | Carbohydrates | 13.31-16.4 g | 70.7-77.5 g | | Fiber | 0.23-0.4 g | 1.4 g | | Ash | 0.37-0.5 g | 1.5-2.0 g | | Calcium | 8-10 mg | 33 mg | | Phosphorus | 30-42 mg | | | Iron | 0.4 mg | 1.7 mg | | Sodium | 3 mg | 3 mg | | Potassium | 170 mg | 1,100 mg | | Thiamine | 28 mcg | | | Nicotinic Acid | 0.4 mg | | | Riboflavin | 0.05 mg | 0.05 mg | | Ascorbic Acid | 24-60 mg | 42 mg |
*According to analyses made in China, India and the Philippines. |
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The lychee is low in phenols and non-astringent in all stages of maturity.
To
a small extent, lychees are also spiced or pickled, or made into sauce,
preserves or wine. Lychee jelly has been made from blanched, minced
lychees and their accompanying juice, with 1% pectin, and combined
phosphoric and citric acid added to enhance the flavor.
The
flesh of dried lychees is eaten like raisins. Chinese people enjoy
using the dried flesh in their tea as a sweetener in place of sugar.
Whole frozen lychees are thawed in tepid water. They must be consumed very soon, as they discolor and spoil quickly.
Other Uses
In
China, great quantities of honey are harvested from hives near lychee
trees. Honey from bee colonies in lychee groves in Florida is light
amber, of the highest quality, with a rich, delicious flavor like that
of the juice which leaks when the fruit is peeled, and the honey does
not granulate.
Medicinal Uses: Ingested in moderate amounts, the
lychee is said to relieve coughing and to have a beneficial effect on
gastralgia, tumors and enlargements of the glands. One stomach-ulcer
patient in Florida, has reported that, after eating several fresh
lychees he was able to enjoy a large meal that, ordinarily, would have
caused great discomfort. Chinese people believe that excessive
consumption of raw lychees causes fever and nosebleed. According to
legends, ancient devotees have consumed from 300 to 1,000 per day.
In
China, the seeds are credited with an analgesic action and they are
given in neuralgia and orchitis. A tea of the fruit peel is taken to
overcome smallpox eruptions and diarrhea. In India, the seeds are
powdered and, because of their astringency, administered in intestinal
troubles, and they have the reputation there, as in China, of relieving
neuralgic pains. Decoctions of the root, bark and flowers are gargled
to alleviate ailments of the throat. Lychee roots have shown activity
against one type of tumor in experimental animals in the United States
Department of Agriculture/National Cancer Institute Cancer Chemotherapy
Screening Program.
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