Select fields on which groundnut was not raised
in the previous two seasons, unless the variety was same and the crop
in the previous two seasons were certified. In addition, the field should
be well-drained and the soil preferably sandy loam, rich in humus content.
Isolation requirements
Groundnut is a completely self-fertilized
crop. The percentage of natural crossing is practically negligible.
Cross-pollination does not take place because the stigma remains enclosed
in the keel even in fully opened flowers. Hence, an isolation of three
meters from other fields of groundnut is considered sufficient for pure
seed production.
Brief cultural practices
Preparation of land
One ploughing and three to four harrowings, followed
by levelling, brings the field to desired tilth for planting.
Time of sowing
Mid June to first week of July.
Source of seed
Obtain nucleus/breeder’s/foundation seed from a source
approved by a seed certification agency. Before planting make sure that
seed is treated with mercurial fungicides.
Method of sowing
The sowing should be done in lines either behind the
plough in 5 to 8 cm deep furrows, or by seed planter. The depth of seeding
varies from 5 to 8 cm, depending upon soil type and moisture conditions.
Spacing
Row to row, Spreading varieties 45 to 60 cm; Bunch varieties
30 cm; Plant to plant 10 to 15 cm (both for bunchy and spreading type).
Seed rate
Bunch type – 80 to 100 kg per hectare depending upon
seed size, Spreading type –60 to80 kg per ha depending upon seed size.
Fertilization
The usual requirement for a good crop is 25 kg
nitrogen, 50 to 80 kg phosphorus and 30 to 40 kg potash.
Fertilizers such as ammonium sulphate, potassium
chloride and single superphosphate should be chosen to meet fertilizer
requirements.
In soils which are not rich in organic matter a
part of the fertilizer requirement should be met by applying farm yard
manure or compost.
Irrigation
Being a kharif crop, groundnut usually
does not require irrigation. However, in situations of prolonged drought
one to two irrigation may be necessary.
Adequate moisture supply at flowering, seed development
and maturation is necessary to obtain higher seed yields.
Interculture
Weeding when crop is two to three weeks old, at
flowering stage and at the time when pegs begin to enter into the soil
is necessary.
The use of herbicides such as prometrin, lasso
(1 to 2 kg active compound dissolved in 500 to 600 litres of water per
hectare) immediately after sowing has been found useful.
Interculture is necessary to keep soil in a friable
condition. Earthing may also be done to facilitate penetration of pegs
into the soil for bunch and semi-spreading types.
Plant protection
For controlling hairy caterpillar, spray thiodan 35
E.C. (0.5 per cent solution, 800 litres of water per hectare), for aphids
spray metasystoc 25 E.C. (1 litre, dissolved in 1000 litres of water
per hectare) and for control of grubs apply carbofuran ten per cent
granules (12 kg per hectare) at the time of sowing, or dust 40 to 60
kg lindane, one per cent per hectare.
For control of tikka disease spray 0.25 per cent
solution of dithane M-45 or 0.075 per cent duter solution soon after
the symptoms are noticed on plants. Three to four such sprays at intervals
of fifteen days are adequate to control the disease.
Rouging
Off-type plants, easily distinguishable
on the basis of plant size, colour of leaflets, flower colour, etc.,
and diseased plants affected by rosette, mosaic and root rot, etc.,
should be removed from time to time as required.
Harvesting and threshing
When leaves start yellowing and fall down,
the crop is ready for harvest.
At this stage the pods become reticulated and within
it the seed is separated from the shell of the pod.
The plants could be either pulled or dug out and
left in the field for two or three days for sun drying.
Long sun drying should be avoided as it is detrimental
and may result in split seed cotyledons.
Threshing is done either by hand picking or with
the help of suitable machines.
Picking should be done when pods readily separate
from stalks, and the seed rattles in the pods.
After threshing, the pods should be further sun
dried for three to four days to reduce the seed moisture content to
eight to nine per cent.
The shelling of pods should be done with sufficient
care so as to prevent chipping and nicking.
After shelling and cleaning, the seeds should be
stored in a cool dry place.
Seed yield
Average seed yield varies from 15 to 20
qtl per hectare.
Seed Production
