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karanja
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| Pongamia pinnata is one of the few nitrogen
fixing trees (NFTS) to produce seeds containing 30-40% oil.
It is often planted as an ornamental and shade tree but now-a-days
it is considered as alternative source for Bio- Diesel. This
species is commonly called pongam, karanja, or a derivation
of these names. |
Botany:
Pongam (Leguminoceae, subfamily Papilionoideae) is a medium
sized tree that generally attains a height of about 8 m and
a trunk diameter of more than 50 cm. The trunk is generally
short with thick branches spreading into a dense hemispherical
crown of dark green leaves. The bark is thin gray to grayish-
brown, and yellow on the inside. The taproot is thick and long;
lateral roots are numerous and well developed
The alternate, compound pinnate leaves consist of 5 or 7 leaflets
which are arranged in 2 or 3 pairs, and a single terminal leaflet.
Leaflets are 5-10 cm long, 4-6 cm wide, and pointed at the tip.
Flowers, borne on racemes, are pink, light purple, or white.
Pods are elliptical, 3-6 cm long and 2-3 cm wide, thick walled,
and usually contain a single seed. Seeds are 10-20 cm long,
oblong, and light brown in color. |
Ecology:
Native to humid and subtropical environments, pongam thrives
in areas having an annual rainfall ranging from 500 to 2500
mm. in its natural habitat, the maximum temperature ranges from
27 to 38oC and the minimum 1 to16oC. Mature trees can withstand
water logging and slight frost. This species grows to elevations
of 1200 m, but in the Himalayan foothills is not found above
600 m.
Pongam can grow on most soil types ranging from stony to sandy
to clay, including Verticals. It does not do well on dry sands.
It is highly tolerant of salinity. It is common along waterways
or seashores, with its roots in fresh or salt water. Highest
growth rates are observed on well drained soils with assured
moisture. Natural reproduction is profuse by seed and common
by root suckers |
Distribution:
The natural distribution of pongam is along coasts and river
banks in India and Burma. Native to the Asian subcontinent,
this species has been introduced to humid tropical lowlands
in the Philippines, Malaysia, Australia, the Seychelles, the
United States and Indonesia |
Uses
:
Wood: pongam is commonly used as fuel wood. Its wood
is medium to coarse textured. However, it is not durable, is
susceptible to insect attack, and tends to split when sown.
Thus the wood is not considered a quality timber. The wood is
used for cabinet making, cart wheels, posts (NAS 1980), agricultural
implements, tool handles and combs (GOI 1983).
Oil: A thick yellow-orange to brown oil is extracted
from seeds. Yields of 25% of volume are possible using a mechanical
expeller. However, village crushers average a yield of 20% (ICFRE,
undated). The oil has a bitter taste and a disagreeable aroma,
thus it is not considered edible. In India, the oil is used
as a fuel for cooking and lamps. The oil is also used as a lubricant,
water-paint binder, pesticide, and in soap making and tanning
industries. The oil is known to have value in folk medicine
for the treatment of rheumatism, as well as human and animal
skin diseases. It is effective in enhancing the pigmentation
of skin affected by leucoderma or scabies (ICFRE undated). The
oil of Pongam is also used as a substitute for diesel.
Fodder and feed: Opinions vary on the usefulness of this
species as a fodder .The leaves are eaten by cattle and readily
consumed by goats. However, in many areas it is not commonly
eaten by farm animals. Its fodder value is greatest in arid
regions. The oil cake, remaining when oil is extracted from
the seeds, is used as a poultry feed.
Other uses: Dried leaves are used as an insect repellent
in stored grains. The oil cake, when applied to the soil, has
pesticidal value, particularly against nematodes and also improve
soil fertility.
Pongam is often planted in homesteads as a shade or ornamental
tree and in avenue plantings along roadsides and canals. It
is a preferred species for controlling soil erosion and binding
sand dunes because of its dense network of lateral roots. Its
root, bark, leaf, sap, and flower also have medicinal properties. |
Agro-practices
Sowing and Germination:
Pongam is easily established by direct seeds or by planting
nursery-raised seedlings or stump cuttings of 1-2 cm root-collar
diameter. In peninsular India, the seeding season is April to
June, and the seed yield per tree ranges from about 10 kg to
more than 50 kg. There are 1500-1700 seeds per kg. Seeds, which
require no treatment before sowing, remain viable for about
a year when stored air-tight containers
Seed germinates within two weeks of sowing. Seedlings attain
a height of 25-30 cm in their first growing season.
Transplantation:
Transplanting to the field should occur at the beginning of
the next rainy season when seedlings are 60 cm in height (GOI
1983). Seedlings have large root systems. Soil should be retained
around the roots during transplantaion.
The spacing adopted in avenue plantings is about 8 m between
plants. In block planting, the spacing can range from 2 x 2
to 5 x 5 m. Pongam seedlings withstand shade very well and can
be interplanted in existing tree stands
MANAGEMENT:
Pongam should be grown in full sun or partial shade on well-drained
soil. A relatively low maintenance tree once established, is
resistant to high winds and drought but is susceptible to freezing
temperatures below 30-degrees F. Pongam will show nutritional
deficiencies if grown on soil with a pH above 7.5. Space major
limbs along the trunk to increase the structural strength of
the tree. Keep limbs less than two-thirds the diameter of the
trunk to help ensure that branches are well secured to the tree.
Pests:
No pests are of major concern, but caterpillars occasionally
cause some defoliation.
Diseases:
No diseases are of major concern.
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Petroleum Conservation Research Association, India |
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