What is Jatropha Curcas?
In Cambodia, Jatropha Curcas is found in all over the country and is generally grown as a live fence for protection of agricultural fields against damage by livestock as it is unpalatable to cattle. It is known in Khmer as "lahong kwong" .
Jatropha Curcas grows almost anywhere, even on gravelly, sandy and saline soils. It can thrive on the poorest stony soil. It can grow even in the crevices of rocks. The leaves shed during the winter months form mulch around the base of the plant. The organic matter from the shed leaves enhance earth-worm activity in the soil around the root-zone of the plants, which improves the fertility of the soil. It grows on well-drained soils with good aeration and is well adapted to marginal soils with low nutrient content. On heavy soils, root formation is reduced. Jatropha is a highly adaptable species, but its strength as a crop comes from its ability to grow on very poor and dry sites.
Regarding climate, Jatropha Curcas is found in the tropics and subtropics and likes heat, although it does well even in lower temperatures and can withstand a light frost. Its water requirement is extremely low and it can stand long periods of drought by shedding most of its leaves to reduce transpiration loss. Jatropha is also suitable for preventing soil erosion.
It is a small tree or shrub with smooth gray bark, which exudes whitish colored, watery latex when cut. Normally, it grows between three and five meters in height, but can attain a height of up to eight or ten meters under favourable conditions.
It can be easily propagated by seeds or cuttings.
The trees are deciduous, shedding the leaves in the dry season. Flowering occurs during the wet season and two flowering peaks are often seen. In permanently humid regions, flowering occurs throughout the year. The seeds mature about three months after flowering. Early growth is fast and with good rainfall conditions nursery plants may bear fruits after the first rainy season, direct sown plants after the second rainy season. The flowers are pollinated by insects especially honey bees.
Fruits are produced in winter when the shrub is leafless, or it may produce several crops during the year if soil moisture is good and temperatures are sufficiently high. Each inflorescence yields a bunch of approximately 10 or more fruits. The seeds become mature when the capsule changes from green to yellow, after two to four months. The plants 1st year yields increases until it reaches its optimum yield in the 6th year.
Two by two metre spacing can accommodate 2500 plants per hectare. The seeds are crushed to extract raw oil, a process that also provides organic fertilizer from the husks. Jatropha seeds contain about 35% of non-edible oil. And the annual nut yield ranges from 0.5 to 12 tons.
Jatropha oil is used for making soap, candles, and biodiesel, and can be used as a varnish, a lubricant, hydraulic oil etc. Jatropha oil is an environmentally safe, cost-effective, renewable source of non-conventional energy.