Jatropha is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas L.), from the family Euphorbiaceae. The name is derived from (Greek iatros = physician and trophe = nutrition), hence the common name physic nut. Jatropha is native to Central America and has become naturalized in many tropical and subtropical areas, including India, Africa, and North America. Originating in the Caribbean, Jatropha was spread as a valuable hedge plant to Africa and Asia by Portuguese traders. The mature small trees bear separate male and female flowers, and do not grow very tall. As with many members of the family Euphorbiaceae, Jatropha contains compounds that are highly toxic.
The hardy Jatropha is resistant to drought and pests, and produces seeds containing up to 40% oil. When the seeds are crushed and processed, the resulting oil can be used in a standard diesel engine, while the residue can also be processed into biomass to power electricity plants.
Goldman Sachs recently cited Jatropha curcas as one of the best candidates for future biodiesel production. However, despite its abundance and use as an oil and reclamation plant, none of the Jatropha species have been properly domesticated and, as a result, its productivity is variable, and the long-term impact of its large-scale use on soil quality and the environment is unknown.
Currently the oil from Jatropha curcas seeds is used for making biodiesel fuel in Philippines, promoted by a law authored by Philippine senators Miriam Defensor-Santiago and Miguel Zubiri. Likewise, jatropha oil is being promoted as an easily grown biofuel crop in hundreds of projects throughout India and other developing countries. The railway line between Mumbai and Delhi is planted with Jatropha and the train itself runs on 15-20% biodiesel. In Africa, cultivation of Jatropha is being promoted and it is grown successfully in countries such as Mali. In the Gran Chaco of Paraguay, where also a native variety (Jatropha matacensis) grows, studies have shown suitability of Jatropha cultivation and agro producers are starting to consider planting in the region.
Estimates of Jatropha seed yield vary widely, due to a lack of research data, the genetic diversity of the crop, the range of environments in which it is grown, and Jatropha's perennial life cycle. Seed yields under cultivation can range from 1,500 to 2,000 kilograms per hectare, corresponding to extractable oil yields of 540 to 680 litres per hectare (58 to 73 US gallons per acre).
Jatropha can also be intercropped with other cash crops such as coffee, sugar, fruits and vegetables.
Air New Zealand is planning a 747 jumbo jet flight from Auckland in the fall of 2008 with one of the four engines being powered by fuel refined from the seed of the fast-growing plant. The three-hour test flight could mark one of the more promising -- and more unusual -- steps by the financially strapped airline industry to find cheaper and more environmentally friendly alternatives to fossil fuel. The airline announced plans to use the new fuel for 10% of its needs by 2013. The jatropha oil is also significantly cheaper than crude oil. It could cost an estimated $43 a barrel, or about one-third of June 4, 2008 closing price of $122.30 for a barrel of crude oil.
Species of Jatropha include: