Jatropha curcas

Jatropha curcas or Barbados nut or Physic nut is a perennial poisonous shrub (up to 5 m high^[1]]) belonging to the Euphorbiaceae or spurge family. The plant, originating in Central America, is mainly grown in Asia and in Africa, where it is known as Pourghère. It is resistant to a high degree of aridity and as such does not compete with food crops. When the seeds are crushed, the resulting jatropha oil can be processed to produce a high-quality biodiesel fuel that can be used in a standard diesel engine.

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Cultivation

  Cultivation is uncomplicated. Jatropha curcas can grow in wastelands and grows almost anywhere, even on gravelly, sandy and saline soils. It can thrive on the poorest stony soil and grow in the crevices of rocks. Complete germination is achieved within 9 days. Adding manure during the germination has negative effects during that phase, but is favourable if applied after germination is achieved. However, it is usually multiplied by cuttings, because this gives faster results than multiplication by seeds. The flowers only develop terminally, so a good ramification (plants presenting many branches) produces the greatest amount of fruits. Another productivity factor is the ratio between female and male flowers within an inflorescence (usually about 1 female to 10 male flowers - more female flowers mean more fruits)^[2]. Jatropha curcas thrives on a mere 250 mm (10 in) of rain a year, and only during its first two years does it need to be watered in the closing days of the dry season. Ploughing and planting are not needed regularly, as this shrub has a life expectancy of approximately forty years. The use of pesticides and other polluting substances are not necessary, due to the pesticidal and fungicidal properties of the plant.

In the early 1990s, a growth trial in Nicaragua covering 2000 hectares (4940 acres) did not live up to expectations, yielding only a disappointing 200 litres of Jatropha oil per hectare (21 US gallons/acre).^{[citation needed]} However, Jatropha is well able to yield as much as 1900 litres of diester per hectare (200 US gallons/acre), largely exceeding the capacity of rapeseed.^[3]

Processing

Seed extraction is made simple with the use of the Universal Nut Sheller, an appropriate technology designed by the Full Belly Project.^[4] The oily seeds are processed into oil, which may be directly used to fuel combustion engines or may be subjected to transesterification to produce biodiesel. Jatropha oil is not suitable for human consumption. A colourant can also be derived from the seed.

Biodiesel potential

Main article: Jatropha biodiesel

Other uses

(The information in this section is largely inspired from the Purdue University - Center for New Crops and Plants Products website ^[5].)

• Leaves

The young leaves may be safely eaten, steamed or stewed. Cooked with goat meat, they are said to advantageously counteract its smell.

Pounded leaves are applied near horses' eyes to repel flies in India.

• Flowers

The species is listed as a honey plant^[6].

• Nuts

Sometimes roasted and eaten, although they are purgative.

They can be burned like candlenuts when strung on grass^[7].

Used as a contraceptive in South Sudan^[8].

• Seeds

Also used as a contraceptive in South Sudan^[9].

The oil has been used for illumination, soap, candles, the adulteration of olive oil, and making Turkey red oil. Turkey red oil, also called sulphonated (or sulfated) castor oil, is the only oil that completely disperses in water. It is made by adding sulfuric acid to pure Jatropha oil^[10]. It was the first synthetic detergent after ordinary Soap, as this allows easy use for making bath oil products. It is used in formulating lubricants, softeners, and dyeing assistants^[11].

The seeds in the zone around Misantla, Veracruz are very appreciated by the population as food once they have been boiled and roasted. It is unclear if this is due to the existence of a non-toxic variety of Jatropha in Mexico and Central America, or if the seeds become eatable once processed by cooking^[12].

It is also similarly reported that Jatropha seeds are edible once the embryo has been removed^[13]. Again it may be so because of these seeds coming from a local non-toxic variety.

• Roots

Their ashes are used as a salt substitute^[14]. It can be used to kill molluscs^[15], and has been listed for homicide, piscicide, and raticide as well^[16].

• Bark

Used as a fish poison^[17].

• Latex

Strongly inhibits the watermelon mosaic virus^[18].

• Sap

It stains linen. Sometimes used for marking^[19].

• Shrub

Mexicans grow the shrub as a host for the lac insect, which is used in medicine as hepatoprotective and antiobesity drug. (Picture of lac insect here [7]; drawing of insect, its larva and a colony here[8])

Used for erosion control^[1], ^[20]

Other names

• Pinhão manso in Brazil
• Tempate in Nicaragua
• kasla in Philippines
• Purging nut

See also

• Jatropha
• Energy crop
• Non food crop

References