Jatropha curcas is a species of flowering plant in the spurge family, Euphorbiaceae, that is native to the American tropics: Mexico, the Caribbean and Central and South America. It has been spread to tropical and subtropical regions around the world, becoming naturalized or invasive in many areas. The specific epithet, "curcas", was first used by Portuguese physician and naturalist Garcia de Orta more than 400 years ago. Common names in English include physic nut, Barbados nut, poison nut, bubble bush or purging nut. In parts of Africa and areas in Asia such as India it is often known as "castor oil plant" or "hedge castor oil plant", but it is not the same as the castor oil plant, Ricinus communis.
Jatropha curcas is a semi-evergreen shrub or small tree, reaching a height of or more. It is resistant to a high degree of aridity, allowing it to grow in deserts. It contains phorbol esters, which are considered toxic. However, edible (non-toxic) varieties native to Mexico also exist, known by the local population as piñón manso, xuta, chutacurcaste, among others.Martínez-Herrera, J., Martínez Ayala, A., Makkar, H.P.S., Francis, G., Becker, K. 2010. Agroclimatic conditions, chemical and nutritional characterization of different provenances of Jatropha curcas L. from Mexico. Journal of Food Quality 35:152-158. J. curcas also contains compounds such as trypsin inhibitors, phytate, saponins and a type of lectinMakkar, H.P.S., Francis, G., Becker, K. 2008. Protein concentrate from Jatropha curcas screw-pressed seed cake and toxic and antinutritional factors in protein concentrate. Journal of Science of Food and Agriculture 88: 1542-1548.Martínez-Herrera, J., Jiménez-Martínez, C., Martínez Ayala, A., Garduño-Siciliano, L., Mora-Escobedo, R., Dávila-Ortiz, G., Chamorro-Cevallos, G., Makkar, H.P.S., Francis, G., Becker, K. 2012. Evaluation of the nutritional quality of non-toxic kernel flour from Jatropha curcas L. in rats. Journal of Food Quality 35:152-158. known as curcin.
The seeds contain 27–40% oil (average: 34.4%) that can be processed to produce a high-quality biodiesel fuel, usable in a standard diesel engine. The oil is a strong laxative. Edible (non-toxic) varieties, as those developed by selection by ethnic Mexican natives in Veracruz, can be used for animal feed and food.Francis, G., Oliver, J., Sujatha, M. 2013. Non-toxic jatropha plants as a potential multipurpose multi-use oilseed crop. Industrial Crops and Products 42: 397-401.
Description Leaves: The leaves have significant variability in their morphology. In general, the leaves are green to pale green, alternate to subopposite, and three- to five-lobed with a spiral phyllotaxis.Nahar, K. and Ozores-Hampton, M. (2011). Jatropha: An Alternative Substitute to Fossil Fuel .(IFAS Publication Number HS1193 ). Gainesville: University of Florida, Institute of Food and Agricultural Sciences. Retrieved (12-17-2011). Flowers: male and female flowers are produced on the same inflorescence, averaging 20 male flowers to each female flower, or 10 male flowers to each female flower. The inflorescence can be formed in the leaf axil. Plants occasionally present hermaphroditic flowers. Fruits : fruits are produced in winter, or there may be several crops during the year if soil moisture is good and temperatures are sufficiently high. Most fruit production is concentrated from midsummer to late fall with variations in production peaks where some plants have two or three harvests and some produce continuously through the season. Seeds: the seeds are mature when the capsule changes from green to yellow. The seeds contain around 20% saturated fatty acids and 80% unsaturated fatty acids, and they yield 25–40% oil by weight. In addition, the seeds contain other chemical compounds, such as saccharose, raffinose, stachyose, glucose, fructose, galactose, and protein. The oil is largely made up of oleic and linoleic acids. Furthermore, the plant also contains curcasin, arachidic, myristic, palmitic, and stearic acids and curcin. Genome: the whole genome was sequenced by Kazusa DNA Research Institute, Chiba Japan in October 2010.
Propagation Jatropha curcas can easily be propagated by both seed or cuttings. Some people recommend propagation by seed for establishment of long-lived plantations. When jatropha plants develop from cuttings, they produce many branches but yield fewer seeds and do not have enough time to develop their taproot, which makes them sensitive to wind erosion. The seeds exhibit orthodox storage behaviour, that is, they can be dried for long-term storage. Propagation through seed (sexual propagation) leads to a lot of genetic variability in terms of growth, biomass, seed yield and oil content. Clonal techniques can help in overcoming these problems. Vegetative propagation has been achieved by stem cuttings, grafting, budding as well as by air layering techniques. Cuttings should be taken preferably from juvenile plants and treated with 200 micro gram per litre of IBA (rooting hormone) to ensure the highest level of rooting in stem cuttings. Cuttings strike root easily stuck in the ground without use of hormones.
Cultivation
Cultivation is uncomplicated. Jatropha curcas grows in tropical and subtropical regions. The plant can grow in wastelands and grows on almost any terrain, even on gravelly, sandy and saline soils. It can thrive in poor and stony soils, although new research suggests that the plant's ability to adapt to these poor soils is not as extensive as had been previously stated. Complete germination is achieved within 9 days. Adding manure during the germination has negative effects during that phase, but is favorable if applied after germination is achieved. It can be propagated by cuttings, which yields faster results than multiplication by seeds.
The flowers only develop terminally (at the end of a stem), so a good ramification (plants presenting many branches) produces the greatest amount of fruits. The plants are self-compatible.A.C.P. Juhász, S. Pimenta, B.O. Soares, Batista Morais de Lourdes, D., Rabello, H. de Oliveira 2009. Floral biology and artificial pollination in physic nut in the north of Minas Gerais state, Brazil [Biologia floral e polinização artificial de pinhão-manso no norte de Minas Gerais] Pesquisa Agropecuaria Brasileira, 44(9): 1073–1077 (in Portuguese). Another productivity factor is the ratio between female and male flowers within an inflorescence, more female flowers mean more fruits."Generative propagation of Jatropha curcas L. on Kalahari Sand." in The Jatropha Journal. Jatropha curcas thrives on a mere 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 is not necessary, due to the pesticidal and fungicidal properties of the plant. It is used in rural Bengal for dhobi itch (a common fungal infection of the skin).
While Jatropha curcas starts yielding from 9–12 months time, the best yields are obtained only after 2–3 years time. The seed production is around 3.5 tons per hectare (seed production ranges from about 0.4 t/ha in the first year to over 5 t/ha after 3 years). If planted in hedges, the reported productivity of Jatropha is from 0.8 to 1.0 kg of seed per meter of live fence.
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Processing Seed extraction and processing generally needs specialized facilities.
Oil content varies from 28% to 30% and 80% extraction, one hectare of plantation will give 400 to 600 litres of oil if the soil is average.
The oily seeds are processed into oil, which may be used directly ("Straight Vegetable Oil") to fuel combustion engines or may be subjected to transesterification to produce biodiesel. Jatropha oil is not suitable for human consumption, as it induces strong vomiting and diarrhea.
Biofuel
When jatropha seeds are crushed, the resulting jatropha oil can be processed to produce a high-quality biofuel or biodiesel that can be used in a standard diesel car or further processed into jet fuel, while the residue (press cake) can also be used as biomass feedstock to power electricity plants, or used as fertilizer (it contains nitrogen, phosphorus and potassium). The cake can also be used as feed in digesters and gasifiers to produce biogas.Poison plant could help to cure the planet Times Online, 28 July 2007.
There are several forms of biofuel, often manufactured using sedimentation, centrifugation, and filtration. The fats and oils are turned into esters while separating the glycerin. At the end of the process, the glycerin settles and the biofuel floats. The process through which the glycerin is separated from the biodiesel is known as transesterification. Glycerin is another by-product from Jatropha oil processing that can add value to the crop. Transesterification is a simple chemical reaction that neutralizes the free fatty acids present in any fatty substances in Jatropha. A chemical exchange takes place between the alkoxy groups of an ester compound by an alcohol. Usually, methanol and ethanol are used for the purpose. The reaction occurs in the presence of a catalyst, usually sodium hydroxide (NaOH) or caustic soda and potassium hydroxide (KOH), which forms fatty esters (e.g., methyl or ethyl esters), commonly known as biodiesel. It takes approximately 10% of methyl alcohol by weight of the fatty substance to start the transesterification process.
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 Jatrophas 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 gallons per acre). In 2009 Time magazine cited the potential for as much as 1,600 gallons of diesel fuel per acre per year. The plant may yield more than four times as much fuel per hectare as soybean, and more than ten times that of maize (corn), but at the same time it requires five times as much water per unit of energy produced as does corn (see below). A hectare of jatropha has been claimed to produce 1,892 litres of fuel. However, as it has not yet been domesticated or improved by plant breeders, yields are variable.
Jatropha can also be intercropped with other cash crops such as coffee, sugar, fruits and vegetables.
However, despite its abundance and use as an oil and reclamation plant, none of the Jatropha species has 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.World Agroforestry Centre (2007) When oil grows on trees
In 2008 researchers at Daimler Chrysler Research explored the use of jatropha oil for automotive use, concluding that although jatropha oil as fuel "has not yet reached optimal quality, ... it already fulfills the EU norm for biodiesel quality". Archer Daniels Midland Company, Bayer CropScience and Daimler AG have a joint project to develop jatropha as a biofuel.Bayer CropScience Press Release, June 18, 2008. Jatropha - This particular oil well holds a lot of future promise Three Mercedes cars powered by Jatropha diesel have already put some 30,000 kilometres behind them. The project is supported by DaimlerChrysler and by the German Association for Investment and Development (Deutschen Investitions- und Entwicklungsgesellschaft, DEG).
Jet fuel