Food Plants International

51
Names
English: Peanut Scientific name: Arachis hypogea L.
Tok pisin: Pinat Synonyms:
Tok ples: Plant family: Fabaceae
Description: A spreading bushy plant that grows up to
about 40 cm high. Leaves are made up of 2 pairs of
leaflets arranged opposite each other. Flowers are
produced in the axils of leaves. Two main kinds occur.
They are often called runner and bunch types. The
runner kind has a vegetative or leafy branch between
each fruiting branch and therefore produces a more
spreading type of plant. This is called "Virginia"
peanut. The pods have 2 dark brown seeds. The other
kind produces fruiting branches in a sequence one after
the other along the branches. These are called
"Spanish-Valencia" types. They grow as a more
upright plant and grow more quickly. They have
lighter coloured leaves and the pods have 2 to 6 seeds
that are often white. Virginia types have the flowers in
alternate pairs.
Spanish and Valencia types have several flower branches one after another along the stem. Pods
are produced on long stalks that extend under the ground. The stalk or peg from the flower
grows down into the soil and then produces the pod and seed under the ground. The flower
needs to be no more than 18 cm from the soil for the seedpod to develop under ground.
Distribution: Peanuts grow well from sea level up to about 1650 metres altitude in the
equatorial tropics. They need a temperature of about 28°C and between 24°C and 33°C. The
plants get killed by frost. They need a well drained soil and cannot stand waterlogging.
Therefore they are often grown on raised garden beds. They do better in drier areas but need 300
to 500 mm of rain during the growing season. Near harvest dry weather is needed. Short season
cultivars are used in semi arid regions. It suits hardiness zones 8-12. Peanuts require soil with
good levels of calcium or they produce empty pods. Adding gypsum will improve this. If the
nutrient boron is short then flowers won't flower and fruit properly. Because peanuts are
legumes, they have root nodule bacteria that can fix their own nitrogen and this means they can
still give good yields in grassland soils where nitrogen is at a lower level
Cultivation: The seeds or nuts are normally removed from the shell before planting and are
sown 2 to 3 cm deep. The alternately branched or Virginia-type of peanuts have a dormancy
period so that they must be stored before replanting. A suitable spacing is 10 cm between plants
and 60 to 80 cm between rows. Often plants are grown in mixed cultures with other plants but
where a pure stand is used up to 250,000 plants per hectare are used. The soil needs to be
weeded and loose by the time the flowers are produced to allow the peg for the seedpods to
penetrate the soil. Normally when the whole plant dies off the plant are ready to pull. They are
left to dry in the sun for 3 or 4 days.
Production: Flowering may commence in 30 days. It takes from 3.5 to 5 months till maturity.
They are harvested when the top of the plants die. The whole plant is pulled out. Virginia
peanuts have a longer growing season and the seeds need to be stored for a while before they
will start to regrow. (30 days.)
Use: The seeds can be eaten raw, or cooked. The young leaves are edible, cooked.
Oil is extracted from the seeds and is edible. The remaining meal is also eaten.