Anacardium occidentale L.
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
Many parts of the cashew plant are used. The cashew "apple," the
enlarged fully ripe, fruit may be eaten raw, or preserved as jam or sweetmeat.
The juice is made into a beverage (Brazil cajuado) or fermented into a wine.
Fruits or seeds of the cashew are consumed whole, roasted, shelled and salted,
in Madeira wine, or mixed in chocolates. Shelling the roasted fruits yields
the cashew nut of commerce. Seeds yield about 45% of a pale yellow, bland,
edible oil, resembling almond oil. From the shells or hulls is extracted a
black, acrid, powerful vesicant oil, used as a preservative and water-proofing
agent in insulating varnishes, in manufacture of typewriter rolls, in oil- and
acid-proof cements and tiles, in brake-linings, as an excellent lubricant in
magneto armatures in airplanes, and for termite proofing timbers. Timber is
used in furniture making, boat building, packing cases and in the production of
charcoal. Bark used in tanning. Stems exude a clear gum, Cashawa gum, used in
pharmaceuticals and as substitute for gum arabic. Juice turns black on
exposure to air and provides an indelible ink. Along the coast of Orissa,
shelter belts and wind breaks, planted to stabilize sand dunes and protect the
adjacent fertile agricultural land from drifting sand, have yielded economic
cashew crops 5 years after planting (Patro and Behera, 1979).
The fruit bark juice and the nut oil are both said to be folk remedies
for calluses, corns, and warts, cancerous ulcers, and even elephantiasis.
Anacardol and anacardic acid have shown some activity against Walker
carcinosarcoma 256. Decoction of the astringent bark given for severe diarrhea
and thrush. Old leaves are applied to skin afflictions and burns (tannin
applied to burns is liepatocarcinogenic). Oily substance from pericarp used
for cracks on the feet. Cuna Indians used the bark in herb teas for asthma,
colds,and congestion. The seed oil is believed to be alexeritic and
amebicidal; used to treat gingivitis, malaria, and syphilitic ulcers.
Ayurvedic medicin recommends the fruit for anthelmintic, aphrodisiac, ascites,
dysentery, fever, inappetence, leucoderma, piles, tumors, and obstinate ulcers.
In the Gold Coast, the bark and leaves are used for sore gums and toothache.
Juice of the fruit is used for hemoptysis. Sap discutient, fungicidal,
repellent. Leaf decoction gargled for sore throat. Cubans use the resin for
cold treatments. The plant exhibits hypoglycemic acitivity. In Malaya, the
bark decoction is used for diarrhea. In Indonesia, older leaves are poulticed
onto burns and skin diseases. Juice from the apple is used to treat quinsy in
Indonesia, dysentery in the Philippines.
He who cuts the wood or eats cashew nuts or stirs his drink with a
cashew swizzle stick is possibly subject to a dermatitis.
Per 100 g, the mature seed is reported to contain 542 calories, 7.6 g H2O, 17.4 g protein, 43.4 g fat, 29.2 g total carbohydrate, 1.4 g fiber,
2.4 g ash, 76 mg Ca, 578 mg P, 18.0 mg Fe, 0.65 mg thiamine, 0.25 mg
riboflavin, 1.6 mg niacin, and 7 mg ascorbic acid. Per 100 g, the mature seed
is reported to contain 561 calories, 5.2 g H2O, 17.2 g protein, 45.7 g fat,
29.3 g total carbohydrate, 1.4 g fiber, 2.6 g ash, 38 mg Ca, 373 mg P, 3.8 mg
Fe, 15 mg Na, 464 mg K, 60 mg b-carotene equivalent, 0.43 mg thiamine, 0.25
mg riboflavin, and 1.8 mg niacin. Per 100 g, the mature seed is reported to
contain 533 calories, 2.7 g H2O, 15.2 g protein, 37.0 g fat, 42.0 g total
carbohydrate, 1.4 g fiber, 3.1 g ash, 24 mg Ca, 580 mg P, 1.8 mg Fe, 0.85 mg
thiamine, 0.32 mg riboflavin, and 2.1 mg niacin. The apple contains 87.9%
water, 0.2% protein, 0.1% fat, 11.6% carbohydrate, 0.2% ash, 0.01% Ca, 0.01% P,
.002% Fe, 0.26% vitamin C, and 0.09% carotene. The testa contains
a-catechin, b-sitosterol, and 1-epicatechin; also proanthocyanadine
leucocyanadine, and leucopelargodonidine. The dark color of the nut is due to
an iron-polyphenol complex. The shell oil contains about 90% anacardic acid
(C22H32O3 and 10% cardol (C32H27O4). It yields glycerides, linoleic,
palmitic, stearic, and lignoceric acids, and sitosterol. Examining 24
different cashews, Murthy and Yadava (1972) reported that the oil content of
the shell ranged from 16.6 to 32.9%, of the kernel from 34.5 to 46.8%.
Reducing sugars ranged from 0.9 to 3.2%, non-reducing sugars, 1.3 to 5.8%,
total sugars from 2.4 to 8.7%, starch from 4.7 to 11.2%. Gum exudates contain
arabinose, galactose, rhamnose, and xylose.
Spreading evergreen perennial tree to 12 m tall; leaves simple,
alternate, obovate, glabrous, penninerved, to 20 cm long, 15 cm wide, apically
rounded or notched, entire, short petiolate; flowers numerous in terminal
panicles, 1020 cm long, male or female, green and reddish, radially
symmetrical nearly; sepals 5; petals 5; stamens 10; ovary one-locular,
one-ovulate, style simple; fruit a reniform achene, about 3 cm long, 2.5 cm
wide, attached to the distal end of an enlarged pedicel and hypocarp, called
the cashew-apple; this shiny, red or yellowish, pear-shaped, soft, juicy, 1020
cm long, 48 cm broad; fruit reniform, edible, with two large white cotyledons
and a small embryo, surrounded by a hard pericarp which is cellular and oily,
oil is poisonous causing allergenic reactions in some humans. Fl. variable.
Several varieties have been selected based on yield and nut size.
Reported from the South America, and Middle America Centers of Diversity,
cashew or cvs thereof is reported to tolerate aluminum, drought, fire, insects,
laterite, low pH, poor soil, sand, shade, slope, and savanna. (2n = 42,
Native to tropical America, from Mexico and West Indies to Brazil and
Peru. The cashew tree is pantropical, especially in coastal areas.
Ranging from Warm Temperate Moist to Tropical Very Dry to Wet Forest
Life Zones, cashew is reported to tolerate annual precipitation of 7 to 42 dm
(mean of 32 cases = 19.6), annual temperature of 21 to 28°C (mean of 31
cases 25.2), and pH of 4.3 to 8.7 (mean of 21 cases = 64). Grows on sterile,
very shallow and impervious savanna soils, on which few other trees or crops
will grow, but is less tolerant of saline soil than most coastal plants. Does
not tolerate any frost. In Brazil, Johnson (1973) summarizes "optimal
ecological conditions;" annual rainfall 720 dm, minimum temperature 17°C,
maximum temperature 38°C; average annual temperature 2428°C, relative
humidity 6580%; insolation 1,500 to 2,000 hours per year, wind velocity 2.25
km/hr, and dry season 25 months long. It is recommended that cultivation be
limited to nearly level areas of red-yellow podzols, quartziferous sands, and
Cashew germinates slowly and poorly; several nuts are usually planted to
the hole and thinned later. Propagation is generally by seeds, but may be
vegetative from grafting, air-layering or inarching. Planting should be done
in situ as cashew seedlings do not transplant easily. Recommended spacing is
10 x 10 m, thinned to 20 x 20 m after about 10 years, with maximum planting of
250 trees/ha. Once established, field needs little care. Intercropping may be
done the first few years, with cotton, peanut, or yams. Fruits are produced
after three years, during which lower branches and suckers are removed. Full
production is attained by 10th year and continues to bear until about 30 years
old. In dry areas, like Tanzania, flowering occurs in dry season, and fruits
mature in 23 months. Flowers and fruits in various degrees of development are
often present in same panicle.
From flowering stage to ripe fruit requires about 3 months. Mature
fruit falls to the ground where the 'apple' dries away. In wet weather, they
are gathered each day and dried for 13 days. Mechanical means for shelling
have been unsuccessful, so hand labor is required. Cashews are usually roasted
in the shell (to make it brittle and oil less blistering), cracked, and nuts
removed and vacuum packed. In India part of nuts are harvested from wild trees
by people who augment their meager income from other crops grown on poor land.
Kernels extracted by people skilled in breaking open the shells with wooden
hammers without breaking the kernels. Nuts are separated from the fleshy
pedicel and receptacle, seed coat removed by hand, and nuts dried. Fresh green
nuts from Africa and the islands off southern India are shipped to precessing
plants in Western India.
Yields are said to range from 048 kg/tree/year, with an average yield
of 8001,000 kg/ha. Heavy bearing trees often produce nuts considered too
small for the trade. Indian field trials showed that fertilizers could
increase yields of 15-year-old trees from less than 1 kg/tree to >4 and
enabled 6 year olds to average 5.7. Regular applications of 250 g N, 150 g
P2O5 and 150 g K2O/tree resulted in average yield increases of 7001600 kg/ha
(Nambiar and Haridasan, 1979). In Pernambuco, trees produced 1.524.0 kg
each/year, averaging 10.3 kg per tree (Johnson, 1973). At Pacajus (Ceara,
Brazil) trees average 17.4 kg/yr with one tree bearing 48 kg/yr. Major
producers of cashew nuts are India, Tanzania, Mozambique, and Kenya. In 1968
India planted over 224,000 ha in cashews to supply over 200 processing
factories operating all year. In 1971 India produced 90,000 MT, the bulk
exported to United States and USSR. Export price at US ports was $.33/kg.
India imports green nuts from the African countries and processes them for
resale. Import prices in 1971 in India was 1730 rupees/MT. Cashawa Gum is
obtained from the West Indies, Portuguese East Africa, Tanzania and Kenya.
A perennial species, the cashew has already, in the past, yielded
alcohol from the "apple," oil from the nut, and charcoal from the wood. The
"apples" (ca 3035 kg per tree per annum) yield each 2025 cc juice, which,
rich in sugar, was once fermented in India for alcohol production.
Cashew tree has few serious diseases or pests. The following are
reported disease-causing agents, none of which are considered of economic
importance: Aspergillus chevalieri, A. niger, Atelosaccharomyces moachoi,
Balladynastrum anacardii, Botryodiplodia theobromae, Cassytha filiformis,
Cephaleuros mycoides, Ceratocystis sp., Cercospora anacardii,
Colletotrichum capsici, Cytonaema sp., Endomyces anacardii, Fusarium
decemcellulare, Gloeosporium sp., Glomerella cingulata, Meliola
anacardii, Nematospora corylii, Parasaccharomyces giganteus, Pestaliopsis
disseminata, Phyllosticta anacardicola, P. mortoni, Phytophthora palmivora,
Pythium spinosum, Schizotrichum indicum, Sclerotium rolfsii, Trichomerium
psidii, Trichothecium roseum, Valsa eugeniae. Cuscuta chinensis attacks
the tree. In Brazil, high populations of the nematodes Criconemoides,
Scutellonema, and Xiphinema are reported around cashew roots (Lima
et al, 1975). Of insects, Helopeltis spp. have been reported in
Tanzania. Four insects are considered major pests: the white fly
(Aleurodicus cocois), a caterpillar (Anthistarcha
binoculares), a red beetle (Crimissa sp.), and a thripe
(Selenothrips rubrocinctus). Flowers are visited by flies, ants and
other insects, which may serve as pollinators. Artificial pollination is
practiced in some areas.
Complete list of references for Duke, Handbook of Energy Crops
- Johnson, D. 1973. Cashew cultivation in Brazil. Agron. Mocamb. Lourenco
- Lima, J.A.A., Menezes, M., Karan, M. de Q., and Martins, O.F.G. 1975. Genera of
pathogenic nematodes isolated from the rhizophere of cashew tree, Anacardium
occidentale. Fitossanidad, Brazil 1(2):3235.
- Murthy, K.N. and Yadava, R.B.R. 1972. Indian J. Agr. Sci. 42(10):960961.
- Nambiar, M.C. and Haridasan, M. 1979. Fertilizing cashew for higher yields.
Indian Farming 28(12):1617.
- Patro, C. and Behera, R.N. 1979. Cashew helps to fix sand dunes in Orissa.
Indian Farming 28(12):3132.
Last update December 22, 1997