Bold pods, which are healthy, not split, not broken
or diseased, should be handpicked from the harvested crop and dried
separately for seed purpose. The kharif produce can be dried
in the sun.
As high temperatures prevail at the time of the
harvest of the summer crop, the pods have to be dried in shade to avoid
loss in viability of seeds.
The seedpods should be thoroughly dried for a week
or ten days by spreading in thin layer on the drying floor.
Trampling of pods with feet during drying has
to be avoided to prevent breakage of pods and seeds.
Storage of seed pods
After the seedpods are thoroughly dried they should
be stored in a dry place in suitable containers.
A cool, dry and well-ventilated place is considered
best for storing groundnut pods for seed purpose.
Access to moisture has to be avoided. Storage
of the seedpods can be done in baskets or pots or gunny bags depending
on the quantity to be stored.
The containers should be kept on a raised platform
and a layer of sand or ash spread on the platform to keep off ants and
other insects.
If stored in pots or baskets, the mouths of the
containers can be sealed with a mixture of cowdung and mud.
If stored in gunny bags, not more than six bags
should be piled one over the other. Otherwise, there will be loss in
viability of seeds due to heating.
The stored pods should be protected from mice,
rats, insects and other pests.
Shelling of seed pods
Shelling of seed pods should be done two to three
days before sowing as the viability of stored seeds deteriorates fast
and the seeds are also easily attacked by insect pests and fungi.
The delicate seed coat should not be injured in
shelling as this will facilitate entry of fungus and cause decay of
the seed and also reduce viability.
The seeds should be stored in a dry and well-ventilated
place away from moisture.
Shelling of groundnuts has to be done when moisture
content has been reduced to 10 per cent or less.
Shelling is done by hand or pedal operated or hands
operated shellers. Shelling by hand is an extremely tedious, time-consuming
and costly operation.
Power operated sheller has been developed at the
National Agricultural Research Project, Tirupati. This sheller causes
minimum injury to the kernels and reduces the cost of shelling considerably.
Good seed is the foundation for high yields.
Without good seed it will not be possible to establish optimum population
of healthy plants.
Purity, good viability, uniform size and free
from disease is the chief characteristics of good seed.
Purity of seed is essential as mixed seeds will
produce a crop of poor market value.
The quality of seed depends on the conditions
during the development of pod and kernel, method of curing and storage
conditions.
Viability
Germination, stand of the crop and ultimate yields
depend on the viability of the seed.
Bunch type has non-dormant seeds while semi-spreading
and spreading types have dormant seeds.
The non-dormant seeds germinate immediately after
maturity.
The dormant seeds usually require a resting period
of about 60 to 75 days before maximum germination can be obtained.
Dormancy can be broken by the use of Ethrel or
by storing seed along with ripening bananas for three to four days in
sealed airtight containers.
The non-dormant nature of the seed of bunch type
is disadvantageous because if there is a wet spell when seed has matured
and there is delay in harvesting, considerable loss of produce occurs
due to the sprouting of the kernel in the pod itself.
In the case of dormant types, the seed of the
kharif crop cannot be used for raising the rabi or summer
crop unless the interval between maturity in kharif crop and
sowing time of rabi or summer crop is atleast three months.
Soil moisture and temperature are important factors
in germination. Germination is not initiated below a seed moisture content
of 35 per cent while 50 per cent water content is necessary for radical
emergence and extension.
Normally, the germination of seeds of the bunch
type is 90 to 95 per cent and the spreading type 85 to 90 per cent.
Germination less than 85 per cent cannot be considered satisfactory
for groundnut.
Where summer is severe, the seed in unshelled pods
can retain viability for one year.
If shelling is done, the seeds lose their viability
very rapidly and are also attacked by insect pests and fungi.
Shelling of pods for seed should be done only
a few days before sowing and the seeds should be treated with non-mercurial
chemicals immediately after shelling.
The groundnut seed with its high oil content is a good substrate
for the development of pathogens that destroy the germinating
seed.
Small lesions, invisible to the naked-eye, facilitate penetration
of fungi. There are several soil and seed-borne fungal and bacterial
diseases of groundnut which cause considerable damage to seeds before
the seedling emerges from the soil and subsequently to the emerged seedlings.
The damage is less when pods are shelled with hand and is more when
shelled with machine.
It is essential to treat the seed with fungicides immediately after
shelling of pods. The pods should be shelled only a few days before
showing.
The seeds are treated with Captan or Thiram or Dithane M-45 at 3 g/kg
of seed for protecting the seeds and also controlling certain seed borne
diseases.
The treatment is done by rotating the seeds with the chemical, which
is in the form of dust, in a drum or any container until the surface
of the seeds is coated uniformly with the chemical.
This will reduce pre-emergence rots and post-germination mortality
of seedlings. Protection is afforded to the seedling for about 10 days
after emergence.
Mercurial compounds like Ceresan and Agrosan should not be used for
treating seeds as residues are left. Seed treatment does not give complete
and long lasting protection.
It prevents initial losses and ensures a good stand. The germination
and emergence of treated seed is higher than untreated seed.
In the process of shelling, the seed coat of the kernels sometimes
breaks and sometimes the kernel is damaged partly or kernels splits
into half. Even when the seed coat is broken, seed-rot fungi have easy
access to the kernel (cotyledons) and cause decreased germination. All
damaged seeds have to be picked after shelling and rejected.
Studies have shown that seeds retained on 5 mm sieve (100 kernel weight
being above 27 g) emerge early, produce vigorous plants and give higher
yield. Shrivelled and improperly filled seeds should be rejected for
seed purpose..
Seed Rate
JL 24 (zone3,4,5 and 6) : 150 kg/ha TMV - 2: 110 kg/ha KRG-1 (zone
1,2 and 3): 150 kg/ha Other areas : 113 kg/ha
Season
Time of sowing
The rainfed crop is sown with the onset of south-west monsoon, it
is necessary to sow the seeds after the soil has been well soaked with
moisture and the temperature of the soil is optimum for germination.
Seed planter
Inadequate early rains often lead to irregular germination
and emergence. Excessive long periods of drought reduce vitality
of the surviving plant.
The best period for sowing the rabi crop, which is raised on
residual moisture in the soil, is November as sowing in September and
October leads to poor growth of the crop and low yield.
The irrigated summer crop is best sown from December to end of January
for obtaining high yields.
Groundnut crop is seriously affected by curtailment of the growing
season.
Sowing rainfed and irrigated crops early in the season is most conducive
for proper growth and high yields. Late planting always results in low
Rainfed/Kharif: May-June with onset of south-west mansoons Rabi:
November Summer: December-January
The depth of sowing of the seed influences germination
largely by influencing moisture availability and temperature. Although
groundnut can emerge even from a depth of 20 cm, there is evidence that
sowing at depth greater than 10 cm results in reduced emergence.
In light soils, the seeds are sown to a depth
of 5 to 7 cm and in heavier soils to a depth of 4 to 5 cm. If the soil
contains plenty of moisture, the depth of sowing should be less than
when it is moderately dry.
Too shallow sowing limits germination as the upper
layers of the soil dry out before radical emergence.
Slight compaction of the soil over the seed is
necessary to have good contact of the seed with soil and ensure quick
and proper germination and to prevent the birds and ants from lifting
the seed.
This is done by drawing a long beam or a long
blade harrow across the line of sowing.
The methods of sowing followed in India can be broadly classified
into three categories.
Seed drill
bullock drawn or power drawn
Static or Automatic
Dropping the seed with hand in the furrow formed
by the country plough.
Hand dibbling
Seed drill
Groundnut is mostly sown under rainfed conditions with a seed drill.
The number of coulters for a seed drill varies from 3 to 6 and the distance
between the coulters 15 to 16 cm.
The seeds are either directly sown through the fixed hopper (seed
bowl) or through loose hoppers attached to draw tubes which are in turn
loosely tied with ropes to coulters.
A double seed bowl seed-drill is also used for sowing.
The depth of placement of seed is adjusted by adjusting hitching of
the bullocks or in tying the seed drill.
In automatic or mechanical seed drills, the distance between seeds
within a row and depth of planting can be adjusted as also the spacing
between two rows so that the desired spacing can be maintained.
But because of high cost, greater draft power required for drawing
the seed drill and absence of facilities for repairing these drills
in villages, the use of the automatic bullock drawn seed drills is at
present limited.
Since sowing is done in rows uniformly spaced, it is possible to work
an implement for inter-cultivation.
Sowing in the furrows
The seeds are dropped with hand in furrows formed by the country plough.
This is costlier than sowing with a seed drill. It is also not possible
to work an inter-cultivation implement between the rows as the rows
will not be having the same spacing between them all through.
Sometimes seeds are dropped in the furrow through a draw tube attached
to the plough by a rope.
The depth of planting is also difficult to regulate in this method
of sowing and usually the stand of the crop is not uniform.
Hand dibbling
Dibbling seed with hand is practiced mostly in irrigated areas. It
is laborious and time consuming.
The seed rows are opened by a seed drill or tyne hoes and the seeds
are dibbled in the rows.
Even under irrigation sowing can be done using a seed drill when
the soil is dry and then irrigation can be given after the borders or
check basins are formed.
The line sowing of groundnut with seeds drills is best whether the
seed drill used is mechanical or indigenous seed drill, power drawn
or bullock drawn.
In the mechanical seed drill, the dropping of seed is regulated precisely
and a more uniform stand of the crop can be obtained.
Even with indigenous seed drill, experienced labourers, particularly
women, drop the seeds at uniform spacing within the row ensuring uniform
stand.
When the spacing between the rows is properly fixed, the subsequent
operations like between the rows is properly fixed, the subsequent operations
like inter-cultivation and harvest can also be carried out easily with
implements resulting in considerable saving in labour charges.
One of the critical factors limiting yields of
groundnut is low plant population. Survey in farmers’ fields has revealed
that plant population is generally below optimum in most of the fields.
Recommendations for plant populations vary widely.
Most research results indicate that yields are increased mainly by reducing
spacing between rows.
Where moisture is a limiting factor when groundnut
is raised under rainfed conditions, the spacing between the rows has
to be adjusted to the amount of moisture available.
Changes in intra-row spacings have less effect
on yields than changing the spacing between the rows.
The actual spacing depends on the fertility of
the soil, size of the plants at maximum vegetative growth and the extent
they cover the soil.
Area of the soil, which is not covered by the plant,
is the area wasted.
Spacing for Spanish bunh type is 30x10 or 30x15
cm and for Virginia running type 45x15 cm.
Spanish bunch type is grown over 70 per
cent of the area under groundnut. In the bunch type, most of the pods
are formed within a radius of 10 cm from the tap root.
There is no need to provide intra row spacing of
more than 10 cm.
In assured rainfall areas and irrigated areas,
10 cm spacing from plant to plant within a row is optimum. However,
under limited moisture conditions and in soils of poor fertility, it
is necessary to give 15 cm. Spacing between plants within a row.
As groundnut is a remunerative crop, it is not uncommon to raise this
crop continuously year after year. As vines and pods are removed from
the soil, this crop will exhaust the soil.
Continuous cropping of groundnut has not lead to reduction in yield,
if manuring and fertilization is done and pests and diseases are effectively
controlled. But good rotation of crops would help to maintain the fertility
of groundnut soil, improve the organic matter level and physical condition
of the soil and increase the yield level of succeeding crop of groundnut.
Groundnut is rotated with sorghum, pearl millet, maize, gingerly,
cotton, horsegram, etc., under rainfed conditions. Under irrigated conditions,
groundnut is most usually rotated with rice.
Cereals followed by groundnut give increase yields of cereal over
cereal grown year after year without rotation.
Groundnut following cereal also gives increased yields. Groundnut
responds well to residual soil fertility.
Mixed Cropping
Mixed cropping is practiced because of the small size of average farm
holding in India preventing adoption of rotations on a large scale.
Mixed cropping acts as an insurance against vagaries of seasons and
damage due to pests and diseases.
Sorghum, pearl millet, sataria, castor, sesame, safflower, niger,
redgram, field beans, cotton, etc., are generally grown mixed with groundnut.
The yield of groundnut is very much reduced when sorghum is grown
as a mixed crop especially when the groundnut is of a spreading type.
Mixtures are not remunerative as sole crop of groundnut.
Mixtures with cotton, castor and redgram are more profitable than
with other crops.
Mixed cropping of cotton or finger millet with groundnut offers scope
for increasing production of groundnut.
Intercropping
Intercropping offers an opportunity to achieve large yield advantages
inexpensively and easily.
It is found to be advantageous under stress situations. Intercropping
combinations have a potential for better use of moisture compared to
sole cropping presumably because of complementary rooting patterns.
Intercropping pigeonpeas in bunch groundnut in the ratio of 1 : 5
or 1 : 7 has been found to be profitable.
Wherever pearl millet is grown as a pure crop under rainfed conditions,
intercropping with groundnut gives increased net return.
About 60 per cent of kharif groundnut
are grown as a sole crop, year after year on the same piece of land
in which no other crop is grown.
Continuous groundnut cultivation on the same piece
of land affects the long time sustainability of the system by exhausting
soil fertility, increasing the build up insect pests, diseases and weeds
and ultimately lowering the yield.
A sustainable system will involve the well planned
alternate uses of the land through sequential cropping intercropping
relay cropping etc., keeping groundnut as the central commodity of the
system.
Sequential cropping
In general, groundnut does well if planted
after gram crops and groundnut, wheat sequence is common mostly in eastern
(Gujarat and Maharashtra) and northern (Punjab, Haryana and Uttar Pradesh)
parts of India.
In recent years due to frequent shortage of water
supply in the command areas, rice-groundnut sequence has gained importance.
This system is found to be better than rice – rice sequence from monetary,
load of insect pest populations and total water requirement points of
view.
This system is productive also in residual moisture
conditions of the coastal areas of Karnataka. Per unit water used in
rice-rice sequence is higher than rice-groundnut sequence.
About 60 kg N and 90 kg P2O5/ha instead of 30
kg N and 40 kg P2O5/ha in case of groundnut grown in fallow fields could
be applied in high and medium texture soils to overcome the adverse
soil physical environment in the rhizosphere.
Intercropping
Area under kharif groundnut is not
likely to expand any further in India. The most potent way of increasing
the area is by finding a place for groundnut as an inter crop.
This system gives some safety to farmers against
the natural calamities and helps in better utilization of farm resources.
As a result of concerted research efforts stable
and remunerative intercropping systems with cereals, pulses and other
oilseeds have been identified for dry land area.
The most promising intercropping systems identified
in recent years are, intercropping of groundnut and pigeonpea followed
by itnercropping of groundnut with sunflower and groundnut with cereals.
Groundnut based cropping systems in different regions
of country
Soil zone and regions
Water availability period (days)
Double cropping system
Intercropping (with row ratio)
North/Central Karnataka
130-140
Groundnut-sunflower
Groundnut + pigeon pea (3 or 7 : 1)
Humid region of West Bengal Humid and Coastal belt of Andra Pradesh,
Tamil nadu, Karnataka Alfisols and related soils Southern Karnataka
Inoculation of groundnut seed with efficient strains of nitrogen,
fixing bacteria is recommended for areas where groundnut is not generally
grown. Response to inoculation of groundnut seed is not obtained in
areas where groundnut is traditionally grown. In such areas the soils
have usually the necessary nodule bacteria and inoculation has no effect
on yield.
Most of the chemicals used for seed treatment to prevent fungus and
bacterial diseases also kill the inoculating bacteria, thus rendering
artificial inoculation ineffective.
Seed inoculation and seed treatment with fungicides, therefore, tend
to be mutually exclusive. When both are essential, the seed may be treated
with fungicide and the rhizobium culture can be sprayed into the seed
row and then covered with soil.
Granulated rhizobium strains can also be sown with seed. This is done
by applying a granular inoculum to seed, the granules being made by
inoculating 1-2 mm sand particles with peat inoculum using methyl cellulose
as sticker.
Inoculation of seed with rhizobium can be done
by the following methods:
Slurry method
Slurry of 5 per cent jaggery is prepared by dissolving
5 g of jaggery in 95 ml of water. For treating 100 kg of seeds about
800 ml of slurry is necessary.
Two hundred grams of peat based rhizobium culture
is added to the cold slurry. Seed is evenly spread on a slab or cemented
surface and the slurry are poured uniformly on the seed and spread gently
on the seed without rupturing the seed coat.
Then the seeds are dried in the shade and not in
the sun. The seeds can be used immediately after they are thoroughly
dried.
Pelleting
About 200 g of peat based culture is added to 800 ml
of 5 per cent cold jaggery slurry and mixed.
This is adequate to treat 100 kg of seed. The slurry
is poured over uniformly spread seed and the seed rolled to give a coating
of slurry.
When the seed is still wet, 200 g of finely powdered
calcium carbonate is spread over the seed and rolled evenly to get uniform
coating. Pelleted seed can be dried in shade and used.
Trickle method
About 400 g of peat based rhizobium culture is suspended
in 50 litres of water and the suspension trickled into seed rows using
a hopper and bamboo tube. About 50 litres will be adequate per hectare.
All the recommended practices for improving productivity can be brought
under four groups:
Use of improved varieties
Adoption of improved seeding practices
Use of manures and fertilizers
Effective control of pests
If improved varieties adopted to the region are properly chosen, the
yield increase will be about 15 to 20 per cent over the local land races.
So far, 50 groundnut varieties have been released in India of which
10 are through hybridization.
The cost of seed varies from 37 to 50 per cent of the total cost of
cultivation of groundnut. It is, therefore, essential to follow improved
seeding practices to obtain maximum benefit from this investment.
One of the critical factors limiting yields of groundnut is low plant
population. Proper selection of seed is necessary. For this purpose,
the pods from the previous crop have to be dried in shade after harvest,
till moisture is reduced to 10 per cent.
Drying in the hot sun reduces viability of the seed. Bold pods have
to be picked and shelled. Broken, diseased and wrinkled seeds have to
be rejected.
Studies have shown that seeds retained over 5 mm sieve produce vigorous
seedlings and give high yield. Seed treatment with Dithane M-45 costs
only Rs.12 to 16 per hectare. But the benefit is greater as higher population
is obtained than in control due to effect control of seed and soil borne
fungi.
Sowing in lines with seed drill ensures higher population due to placement
of seed at optimum depth resulting in higher yields. Line sowing with
seed drills helps to regulate seed rate and cover large areas within
a short time.
Line sowing permits use of intercultivation implements. The indigenous
bullock drawn seed drills cover 1 to 2 hectares in a day but require
considerable skill and experience in operating them. The bullock drawn
mechanical seed drill is a definite improvement over the local seed
drills.
The spacing between rows can be adjusted. Seed can be covered by attaching
a beam behind the drill.
The use of this drill reduces cost of sowing. Root grub is a serious
pest reducing plant population. Application of Phorate or carbofuran
or Sevidol granules in the soil controls this pest effectively but the
cost varies from Rs.318 to 675 per hectare and this is a heavy investment
for a dryland farmer. Cheaper methods of control have to be developed.
The recommended seed rate and spacing have to be adopted.
The seed rates recommended in India are more than two to three times
the seed rates adopted in USA, Israel, Senegal and other groundnut growing
countries.
There is need to reexamine the recommendations regarding seed rates
as the cost of seed is more than Rs.10 per kg. Preparation of
a good seed bed is essential.
The influence of soil physical environment is very great especially
at the peg penetration and pod development stages. When there is a prolonged
dry spell due to long interval between two rains, the soil in the surface
5 cm depth becomes very hard preventing peg penetration and pod development
in sandy clay loams.
Studies have shown that when bulk density is 1.65 g/cc and above,
peg penetration and pod development are greatly hindered.
These aspects have not been thoroughly investigated and management
practices to prevent the hardening of the surface soil have not been
suggested to the farmers.
Application of farm yard manure, compost, powdered groundnut shells
or gypsum will prevent the soil from becoming hard.
Application of manures and fertilizers increase yield but due to uncertainty
of rainfall, the farmers are reluctant to use fertilizers. It is essential
to use fertilizers if productivity has to be improved.
Farm yard manure or compost is essential for improving the physical
condition of the soil. It supplies micro-nutrients such as iron, zinc
and also helps to improve the rhizobium multiplication in the soil.
Application of 10 t/ha of farm yard manure is beneficial.
Under optimum conditions, groundnut plants can fix atmospheric nitrogen
in their root nodules upto 200 kg N/ha.
The extent of nitrogen fixed depends on the cultivar, rhizobium strain,
soil temperature, soil moisture and nutrients.
Often, conditions are not ideal for the rainfed groundnut crop to
fix optimum quantity of nitrogen. Moreover, the nodules are formed 15
days after seeding and are effective only 30 days after seeding and
the nitrogen fixed in the nodules becomes available then only.
A starter dose of 10 kg N/ha is, therefore, necessary for the rainfed
groundnut crop.
Thirty days later, a few plants in the field can be pulled out at
random and examined for the number and effectiveness of root nodules.
Pink colouration when nodules are cut open indicates effectiveness.
If the root nodules are not in adequate number and size and effective,
it is necessary to apply 10 kg N/ha as top dressing.
There is need to apply phosphorus fertilizer only if the available
phosphorus in the soil is less than 35 kg P2O5/ha.
Single superphosphate is the best source of phosphorus as it has 50
per cent gypsum and provides 19.5 per cent calcium, 12.5 per cent sulphur
and other nutrients such as zinc and magnesium needed for groundnut.
Unless the soil has less than 150 kg K20/ha, there is no
need to apply potassium.
Fifty kg P2O5 and 30 kg K20 will
be adequate for soils deficient in phosphorus and potassium. But, the
dosage have to be decided based on soil test values.
Deficiency of calcium leads to pops. Sulphur is required for the biosynthesis
of oil.
Calcium improves the physical condition of the soil and germination
of seed, reduces respiration, incidence of pod rot, rust and seedling
blight.
Gypsum is the cheapest source of calcium and sulphur. It contains
29.20 per cent calcium and 18.60 per cent sulphur.
Calcium taken up by the roots is not translocated to the developing
pods. The developing pegs and pods take up calcium and sulphur.
Calcium has, therefore, to be made available in the pod zone which
is within 5 cm from the surface of the soil.
About 3 meq of available calcium per 100g of soil is necessary in
the pod zone. Soil usually contains on an average about 2 meq of available
calcium per 100 g of soil.
To supply 1 meq of available calcium per 100 g of soil in 0-5 cm soil
depth, about 500 kg/ha of gypsum is necessary. Powdered gypsum has to
be applied at the base of the plant when the first blooms appear.
Zinc deficiency is often noticed in groundnut soils and it can be
corrected by the application of 50 kg/ha of zinc sulphate once in three
years for rainfed groundnut.
Plant protection measures do not pay every year if adopted as a prophylactic
measure.
The threshold levels have to be determined for each pest and only
when this level is reached the appropriate pest control measure has
to be adopted.
Dust formulations can only be recommended for the rainfed crop. Though,
it pays to adopt plant protection measures the investment is heavy and
the dryland farmer is reluctant to invest. Cheaper methods of pest control
have to be worked out.
Crop Establishment
