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INTRODUCTION
Jatropha
curcus is a drought-resistant perennial, growing well in marginal/poor
soil. It is easy to establish, grows relatively quickly and lives,
producing seeds for 50 years.
Jatropha the wonder plant produces seeds with an oil content of 37%. The
oil can be combusted as fuel without being refined. It burns with clear
smoke-free flame, tested successfully as fuel for simple diesel engine.
The by-products are press cake a good organic fertilizer, oil contains
also insecticide.
It is found to be growing in many parts of the country, rugged in nature
and can survive with minimum inputs and easy to propagate.
Medically it is used for diseases like cancer, piles, snakebite,
paralysis, dropsy etc.
Jatropha grows wild in many areas of India and even thrives on infertile
soil. A good crop can be obtained with little effort. Depending on soil
quality and rainfall, oil can be extracted from the Jatropha nuts after
two to five years. The annual nut yield ranges from 0.5 to 12 tons. The
kernels consist of oil to about 60 percent; this can be transformed into
biodiesel fuel through Estrification.
Family: Euphorbiaceae Synonyms: Curcas purgans Medic. Vernacular/common
names: English- physic nut, purging nut; Hindi - Ratanjyot Jangli erandi;
Malayalam - Katamanak; Tamil - Kattamanakku; Telugu - Pepalam; Kannada -
Kadaharalu; Gujarathi - Jepal; Sanskrit - Kanana randa.
Distribution and habitat
It
is still uncertain where the centre of origin is, but it is believed to
be Mexico and Central America. It has been introduced to Africa and Asia
and is now culti-vated world-wide. This highly drought-resistant
spe-cies is adapted to arid and semi-arid conditions. The current
distribution shows that introduction has been most successful in the
drier regions of the tropics with annual rainfall of 300-1000 mm. It
occurs mainly at lower altitudes (0-500 m) in areas with average an-nual
temperatures well above 20°C but can grow at higher altitudes and
tolerates slight frost. It grows on well-drained soils with good
aeration and is well adapted to marginal soils with low nutrient
content.
Botanical Features
It
is a small tree or shrub with smooth gray bark, which exudes a 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.
Leaves
It
has large green to pale-green leaves, alternate to sub-opposite,
three-to five-lobed with a spiral phyllotaxis.
Flowers
The
petiole length ranges between 6-23 mm. The inflorescence is formed in
the leaf axil. Flowers are formed terminally, individually, with female
flowers usually slightly larger and occurs in the hot seasons. In
conditions where continuous growth occurs, an unbalance of pistillate or
staminate flower production results in a higher number of female
flowers.
Fruits
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
ovoid fruits. A three, bi-valved cocci is formed after the seeds mature
and the fleshy exocarp dries

Seeds
The seeds become mature when the capsule changes from green to yellow,
after two to four months.

Flowering and fruiting habit
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 hu-mid 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.
Ecological Requirements
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 shed leaves
enhance earth-worm activity in the soil around the root-zone of the
plants, which improves the fertility of the soil.
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 and shifting of sand dunes.
Biophysical limits
Altitude:
0-500 m, Mean annual temperature: 20-28 deg. C, Mean annual rainfall:
300-1000 mm or more.
Soil type: 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.
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