Origin and Distribution:
Jatropha curcas is a tropical shrub native to Mexico and Central America, but it is widely distributed in wild or semi cultivated lands in Latin Amercia, Africa, India and south East Asia. In India, Portuguese navigator introduced it in the 16th century. It is drought resistance and this can grown on waste lands. The genus is comopolitan on distribution except in the artic region but they are the genus is distrubuted in the tropical and subtropical Himalayas and the mountains of western and eastern ghats and the plains of South India.
Leaves:
The leaves are usually simple deeply palmately 3-5 lobed. The stipules are usually represented by ciliate glands. The venation is palmate. The leaves are green to pale green broad and glabrous
Inflorescence:
The inflorescence is complex. The first branching is recemose and subsequent branching are cymose. Inflorescence are formed terminally or axillary, with female flowers usually slightly larger. It is formed in the leaf axil small yellowish green flowers are born in loose panicles of cymes.
Fruits:
After pollination fruit is usually a three chambered formed and schizocrpic capsule splitting in to three one seeded cocci. The seeds are often with conspicuous caruncle. Seeds resemble castor in seed in shape, Ovoid, oblong and black in color. The seeds become mature when the capsules from green to yellow, after two to four months after fertilization.
Climatic Requirement:
Jatorpha curcas grows on a wide range of climate and soils. This tree can be established on degraded, gravelly, sandy or saline soils with low nutrient contents. The distribution of jatropha curcas shows that its introduction has been most successful in drier regions of the tropics with an average annual rainfall between 300 and 100 mm. however, Its grows well in areas with higher rainfall. As jatropha curcas occurs mainly at lower altitudes (0-500mm). It is non sensitive to day length being a species or arid and semi arid tropics, it survives on areas receiving very low rainfall. However, it does well even on slightly cool conditions and can withstand and a light frost. jatropha curcas is highly adaptable species, but its strength as a crop comes from its ability to grow on poor and dry sites.
Variety:
For evolving a variety, mass selection and single tree selection followed by progeny evaluation are ideal methods. For this , seeds should be collected from superior seed sources from the natural stand with more than 10 years ago. This represents fair genetic ｅxpression and results in better growth and development. The seeds must contain more than 30% oil only then extraction of oil is economical. High yielding types have been collected and are being evaluated at Tamilnadu Agricultural University, which is ideal for cultivation. At present, superior performing cultures have been identified after conduction performance trails. Such identified cultures are being used for Intra and Inter specific hybridization in order to develop new varieties and hybrids in Jatropha. Besides this, induction of mutation to existing cultures shall pave way for enhancing the existing natural variability. All the techniques are adapted by this institute to develop superior performing varieties with high yield and oil content.
