Agroforestree Database

Local names:
 Afrikaans (purgeerboontjie), Arabic (habel meluk,dand barri), Bengali (bagbherenda,erandagachh), Chinese (yu-lu-tzu), Creole (fey medsen,gran medsinye), Dutch (purgeernoot), English (curcas,Barbados nut,pig nut,physic nut,castor oil,purging nut,fig nut,w

Jatropha curcas is a perennial, monoecious shrub or small tree up to 6 m high; bark pale brown, papery, peeling; slash exudes a copious watery latex, soapy to tough but soon becoming brittle and brownish when dry; branches glabrous, ascending, stout.

Leaves alternate, palmate, petiolate, stipulate; stipules minute; petiole 2-20 cm long, blade 3-5 lobed, 12.5-18 x 11-16 cm, lobes acute or shortly acuminate at the apex, margins entire or undulating, leaf base deeply cordate, glabrous or pubescent only on the veins below, basal veins 7-9, prominent, venation reticulate. 

Inflorescence a cyme formed terminally on branches and complex, possessing main and co-florescences with paracladia. The plant is monoecious and flowers are unisexual; occasionally hermaphroditic flowers occur; 10 stamens arranged in 2 distinct whorls of 5 each in a single column in the androecium and in close proximity to each other. In the gynaecium, the 3 slender styles are connate to about 2/3 of their length, dilating to a massive bifurcate stigma. Female flowers with sepals up to 18 mm long, persistent; ovary 3-locular, ellipsoid, 1.5-2 mm in diameter, style bifid.

Fruit an ellipsoid capsule 2.5-3 cm long, 2-3 cm in diameter, yellow, turning black. Seeds black, 2 per cell, ellipsoid, triangular-convex, 1.5-2 x 1-1.1 cm.

The meaning of the specific name ‘curcas’ is not known. It was first given 400 years ago to ‘certain seeds’ by the Portuguese doctor Garcia de Orto, who published a work on Indian medicinal and drug plants in 1563.

Ecology

As a succulent that sheds its leaves during the dry season, J. curcas is best adapted to arid and semi-arid conditions. Most Jatropha spp. occur in the following seasonally dry areas: grassland-savannah and thorn forest scrub but, are completely lacking from the moist Amazon region. The current distribution of J. curcas shows that introduction has been most successful in drier regions of the tropics. It is very tolerant and thrives under a wide range of climatic and edaphic conditions. It is particularly hardy at medium altitude and in humid zones. It is not sensitive to day length.

J. curcas is a highly adaptable species, but its strength as a crop comes from its ability to grow on poor, dry sites. It is very drought tolerant and can withstand slight frost.

Native range
Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama

Tree management

Seedlings are susceptible to competition from weeds during their early development. Therefore weed control, either mechanical or with herbicides, is required during the establishment phase. Satisfactory planting widths are 2 x 2 m, 2.5 x 2.5 m, and 3 x 3 m. This is equivalent to crop densities of 2500, 1600 and 1111 plants/ha, respectively. Under good rainfall conditions, nursery plants bear fruit after the 1st rainy season, while directly seeded plants bear for the 1st time after the 2nd rainy season. With vegetative propagation, the 1st seed yield is higher. At least 2-3 t of seeds/ha can be achieved in semi-arid areas. 

Live fences can be established quickly by planting cuttings directly in the field. Pruning as a hedge is a frequent practice. J. curcas has a productive life of 40-50 years without necessitating replanting or tending.

Seeds are oily and do not store for long. Seeds older than 15 months show viability below 50%. High levels of viability and low levels of germination shortly after harvest indicate innate (primary) dormancy.

As a succulent that sheds its leaves during the dry season, J. curcas is best adapted to arid and semi-arid conditions. Most Jatropha spp. occur in the following seasonally dry areas: grassland-savannah and thorn forest scrub but, are completely lacking from the moist Amazon region. The current distribution of J. curcas shows that introduction has been most successful in drier regions of the tropics. It is very tolerant and thrives under a wide range of climatic and edaphic conditions. It is particularly hardy at medium altitude and in humid zones. It is not sensitive to day length.

J. curcas is a highly adaptable species, but its strength as a crop comes from its ability to grow on poor, dry sites. It is very drought tolerant and can withstand slight frost.

The species is easily propagated by direct seeding, precultivation of seedlings, transplanting of spontaneous wild plants and direct planting of cuttings. Seed should be collected when capsules split open. Use of fresh seeds improves germination. Intervals of presoaking and drying, or partial removal of the testa, are more successful than presoaking alone. With good moisture conditions, germination takes 10 days. The seed shell splits, the radicula emerges and 4 small peripheral roots are formed. Soon after development of the 1st leaves, the cotyledons wither and fall off. Further growth is sympodial.

Wax: The bark contains a wax composed of a mixture of ‘melissyl alcohol’ and its melissimic acid ester.

Poison: Curcas oil contains a toxin, curcasin. The albumen of the kernel is a poison, toxalbumen cursin, most abundant in the embryo. Another poison, a croton resin, occurs in the seeds and causes redness and pustular eruptions of the skin. The plant is listed as a fish poison. Aqueous extracts of J. curcas leaves were effective in controlling Sclerotium spp., an Azolla fungal pathogen. The seed oil, extracts of J. curcas seeds and phorbol esters from the oil have been used to control various pests, often with successful results. In Gabon, the seeds, ground and mixed with palm oil, are used to kill rats. The oil has purgative properties, but seeds are poisonous; even the remains from pressed seeds can be fatal.

Erosion control: In Cape Verde, J. curcas was recently planted in arid areas for soil-erosion control.

 In Guinea, ashes from the roots and branches are used as cooking salt. Young leaves may be safely eaten when steamed or stewed. Cooked nuts are eaten in certain regions of Mexico

Jatropha oil is an environmentally safe, cost-effective renewable source of non-conventional energy and a promising substitute for diesel, kerosene and other fuels. Physic nut oil was used in engines in Segou, Mali, during World War II. The oil burns without smoke and has been employed for street lighting near Rio de Janeiro. Fruit hulls and seed shells can be used as a fuel. Dried seeds dipped into palm oil are used as torches, which will keep alight even in a strong wind. The wood was used as fuel, though of poor quality, in Cape Verde.

Tannin or dyestuff: Leaf juice stains red and marks linen an indelible black. The 37% tannin found in bark is said to yield a dark blue dye; latex also contains 10% tannin and can be used as marking ink. Ashes from the roots and branches are used in the dyeing industry, and pounded seeds in tanning in Ghana. 

Lipids: The seeds yield up to 31-37% of a valuable oil. It is used to prepare varnish after calcination with iron oxides. Hardened physic nut oil could be a satisfactory substitute for tallow or hardened rice bran oil. In Europe it is used in wool spinning and textile manufacture. Along with burnt plantain ashes, oil is used in making hard homemade soap.

Medicine: Seeds were formerly exported from the Cape Verde Islands to Portugal and the ‘curcas’, or purging oil, from them is a drastic purgative. They resemble groundnuts in flavour, and 15-20 seeds will cause griping, purging and vomiting for 30 minutes. It is reported from Gabon that 1-2 roasted seeds are sufficient to act as a purgative; larger doses may be dangerous. The seeds have been substituted for castor oil and are sometimes called ‘larger castor oil’. The oil is widely used for skin diseases and to soothe pain such as that caused by rheumatism; it is an ingredient in the oily extract, known in Hausa as ‘kufi’, which is a rubifacient for rheumatism and for parasitic skin conditions. The oil is used to stimulate hair growth. The seeds are also used in the treatment of syphilis.  Juice or latex is applied directly to wounds and cuts as a styptic and astringent to clean teeth, gums, and to treat sores on the tongue and in the mouth. Branches are used as a chewing stick in Nigeria. Latex has antibiotic properties against Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Streptococcus pyogens. It also has coagulating effects on blood plasma. A methanol extract of physic nut leaves afforded moderate protection for cultured human lymphoblastoid cells against the cytopathic effects of the human immunodeficiency virus. Preparations of the plant, including seeds, leaves and bark, fresh or as a decoction, are used in traditional medicine and for veterinary purposes. A leaf infusion is used as a diuretic, for bathing, to treat coughs, and as an enema in treating convulsions and fits. Leaves are also used to treat jaundice, fevers, rheumatic pains, guinea worm sores and poor development of the fetus in pregnant women. The leaves produce a sap that has haemostatic properties; it is used to dress wounds. In Ghana the ashes from the burnt leaves are applied by rectal injection for haemorrhoids. The root bark is used to relieve the spasms of infantile tetanus and is used for sores, dysentery and jaundice. The juice of the flowers has numerous medicinal qualities.

Widely cultivated in the tropics as a living fence in fields and settlements. J. curcas is not browsed by cattle; it can grow without protection and can be used as a hedge to protect fields.

Soil improver: Press cake cannot be used in animal feed because of its toxic properties, but it is valuable as organic manure due to a nitrogen content similar to that of seed cake from castor bean and chicken manure.  The nitrogen content ranges from 3.2 to 3.8%, depending on the source. Tender branches and leaves are used as a green manure for coconut trees. All plant parts can be used as a green manure.

Intercropping: In Madagascar, the plant is used as a support for vanilla.