It is a poisonous shrub that is native to central America and Mexico. However, it is now practically pan-tropical and widely-seen across Brazil, India, Salvador, Fiji, and Jamaica, among other countries.
How to Grow this Plant
This plant grows in semi-arid and arid regions, and adapts well in types of soil that are typically not conducive for cultivation, such as sandy, gravelly, or highly-saline soil. It does not require much rainfall, and survives on levels as low as 250 mm a year, though 600 mm is considered optimum and beneficial for growth.
It can also survive long periods of drought. It grows readily from cuttings as well as seeds, and flourishes in temperatures ranging from 20 to 28 °C. Its hardy nature ensures its survival even through slight frost, though this has a direct negative impact on crop levels.
Typically, this plant takes 4-5 years to achieve maturity and propagation is mainly achieved through seed plantation. The full-grown leaves are light-green in color and fairly large. Flowers grow terminally or at the end of a stem and are whitish in color. Fruits develop in winter, when the plant sheds its leaves, which collect at the base and form a mulch.
However, a well-watered plant can produce several crops in a given year when temperatures are at optimum levels. When the capsule of the fruit changes color from green to yellow, the seeds are considered mature. When shelled, the capsules yield blackish, oblong seeds, from which oil is extracted.
The seeds are high in unsaturated fatty acids, up to 79% of the oil extracted. Seeds contain 25 to 40% oil, from which a good-quality biodiesel fuel can be produced.
However, the oil content is not limited to the seeds - the kernels also possess it in high levels. However, this oil contains a compound called Cursin which is poisonous, rendering it unsuitable for human consumption.
There are a number of varieties of this plant, some of which are as follows.
- Jatropha curcas
- Pongamia pinnata
- Castor (Erand)
Uses and Importance
The uses of this hardy plant in present day conditions are many. Apart from producing biodiesel, the oil from the seeds has traditionally been used for a number of other purposes such as lighting, and making soap and candles. In India, the leaves of this plant are pounded to make a paste that is applied near the eyes of horses to repel insects and flies.
It is widely-planted for carbon sequestering. A tree that has achieved maturity can absorb close to 8 kg of carbon dioxide in a year. This translates into about 3 tons of carbon dioxide per acre per year, a property which makes planting it an effective measure for the reduction of greenhouse gas emissions.
The scope of its uses is tremendous. As the world slowly wakes up to the possibilities of this hardy plant and the sources of alternative fuel it offers, its cultivation has increased though awareness is still in the nascent stage.