Groundnut is one of a very important crops in Agriculture since it is an important source of protien and oil.
Common name of groundnut
It is commonly known as – Groundnut, Peanut, Monkey nut, Earth nut, Manila nut, moong fali etc
Meaning of the term groundnut
In Greek language ‘Arachis’ means legume and ‘hypogaea’ means below ground, referring to formation of pods in the soil.
Special name of groundnut
King of Vegetable Oilseeds in India.
Botanical name and Family
Arachis hypogaea and Leguminosae
Economic uses of groundnut
Groundnut oil is the cooking media for preparing different food items.
It is the primary source of vegetable oil requirement to the Asian people.
The groundnut seed contain 47-53% oil and 26% protein and 11.5% starch.
The groundnut kernels are good source of all B-vitamins except B12 and vitamin E.
Groundnut kernels are rich in P, Ca & Mg including micronutrients like Fe, Zn.
Nearly 81% of the kernels are used for oil extraction 12% used for seed purpose, 6% – raw materials, 1% – exported by Hand picked selections (HPS).
Groundnut kernels are also used for the preparation of food products like chikkis, Ground nut milk, G.nut butter, curd including different bakery products
G.nut oil is a major source of edible oil in India.
The inferior quality oil is used for
making soaps, detergents, Cosmetics, paints, candles, Lubricants and some of the
Groundnut oil is used for medicinal purposes especially for massaging polio patients & it is also used as a substitute for olive oil and also for preparation of glycerin.
The oil cakes are used as valuable organic manures & feeding material for live stock. It consists of 7.3% N; 1.5% P2O5 & 1.3% K2O.
The peanut haulms contain crude protein 8–5% lipids 1–3% and minerals 9– 10%.
These are used as cattle feed either in fresh or in dried stage or preparing hay or silage.
The peanut shells or pod walls which constitute nearly about 25% of total pod weight are used as bedding material for poultry or as mulching material during summer season
to reduce the evaporative losses.
Shell material is also used as filler material for making mixed fertilizers and as Insulation material for buildings or as fuel in boilers.
G.nut crop add sufficient quantity of organic matter to the soil as most of the leaves are shed just before harvesting. In some areas, Groundnut is used as a green manure crop.
Groundnut is able to fix atmospheric nitrogen @ 60 – 100 kg N /ha within a season.
Origin and history
Center of origin of Groundnut is South America i.e., Matograsso a place in Brazil.
It appeared that Portuguese introduced the groundnut plant from Brazil into Africa.
At the beginning of 16th century, groundnut was introduced into India by Jesuit fathers who followed Vasco De Gama shortly after his first landing in india
Major countries and states producing groundnut
Major groundnut producing countries are China, India, Nigeria, USA, Indonesia, Argentina, Sudan, Senegal and Myanmar.
India ranks first in area and production in the world
Groundnut accounts for 36% to 40% of total oilseed production in india
The major Groundnut producing states are Gujarat, A.P., T.N., Karnataka & Maharashtra.
Varieties grown in India
The recommended var. of groundnut are JL – 24 (Phule pragathi), TAG -24, Greeshma, Prasuna, Abhaya, Apoorva, ICGV-86590, K – 134, TPT-2, TPT -3, ICGV 86325, DRG 12, Kadiri 4,5,6, Jcc-88, ICGS 11, ICGS – 44 ICGS – 76, Kalahasti, Narayani, TG 26, TMV 2, J-11, Gaug – 1 etc.
Climate and soil
Groundnut is predominantly a crop of the tropics.
The crop can be grown successfully in places receiving a minimum of 500 mm and a maximum of 1250 mm.
From the productivity of groundnut in several countries, it is evident that
semi – arid and arid regions with 500 – 700 mm rainfall during crop period are ideal for groundnut production.
Rainfall should be adequate during flowering and pegging stages.
Ideal RF for successful groundnut crop would be 80 – 120 mm during summer to facilitate preparatory cultivation, 100 – 120 mm ? at sowing, 200 mm from flowering to peg penetration, 200 mm for early pod development to pod maturity
Rainfall is the most important factor limiting the productivity of rainfed groundnut due to variability in amount and distribution of RF.
Continuous rains leads to excessive vegetative growth resulting in poor pod yield
Rains at harvest cause germination of kernels in non-dormant Spanish and Valencia cultivars besides problem in pod drying.
Soil temperature 18 degree C delays emergence of seedlings.
The embryo is killed above 54 Degree C
G.nut performs well in dry temperature range between 24 to 33 degree C and but it can survive up to 45 degree C
Ideal temperature for reproductive stage is b/n 24 – 27
Rate of pod growth will be maximum between 30 to 34 degree C
Groundnut is day length insensitive plant.
About 60% solar radiation for 60 days after emergence appears to be critical.
Low light intensity prior to flowering slows down the vegetative growth and increases the plant height.
Low light intesnsity at early flowering leads to flower abortion
Low light intensity at pegging reduces peg and pod number and pod weight
Flowering phase is more sensitive to reduced light intensities
In the absence of soil moisture stress, clear days have greatest potential for opt. growth and development leading to high pod yield.
Groundnut can be grown on all types of soils such as sandy, sandy loam and heavy black soils.
thrives best on sandy loams.
Most suitable soils for groundnut production are well-drained light sandy loams with an ample supply of calcium and moderate organic matter.
Heavy and stiff clay soils are not desirable as they tend to become hard during dry weather thereby interfering with peg penetration into the soil and also makes the harvest extremely difficult.
Groundnut is one of the most acid tolerant crops with a critical Ph range of 5 – 5.5.
It is moderately sensitive to soil salinity and highly susceptible to waterlogging
Land preparation for groundnut depends on the soil type and onset of monsoon for rainfed crop and on the previous crop grown for irrigated crop.
Light red soils are usually ploughed twice with the summer rains followed by 2 – 3 harrowings.
In general, deep ploughing of light soil once or twice results in higher pod yield than repeated shallow ploughings for rainy season crop as deep ploughing aids in higher rainwater storage in root zone to minimize the adverse effect of drought during the crop season.
In A.P. , black soils are only harrowed (4 – 5 times) several times without any ploughing.
For irrigated crop, one light ploughing (even at high soil moisture content to hasten soilbdrying) followed by harrowing for 3 – 4 times at 2 – 3 days interval.
Optimum depth of ploughing is 15-20 cm.
If too deep ploughing is done, it leads to development of pods in deeper layers which makes the harvesting difficult
The crop growing season should be ideal for growth and development of crop for opt. yield.
90% area is under groundnut is during kharif under rainfed conditions.
Average yields are comparatively low due to erratic behaviour of monsoon i.e late onset of monsoon,
dryspell during critical crop growth stages, heavy rains at later stages or early withdrawl of monsoon.
Pest & disease incidence is also high in kharif. The climate will be cloudy with lesser sunshine.
– season extend from April to August.
– In black soils, sowings may be delayed even upto august/September to avoid heavy rains effect on germination.
G.nut cropping during rabi is limited to areas where winter is not severe and temperature does not go below 15 degree C
It is confined to states of T.N, A.P, Karnataka, Orissa, Maharashtra and Gujarat
It is grown under irrigated on uplands or with supplemental irrigation in rice fallows.
– Sowing period extend from October to December.
– Second half of November is the ideal sowing time.
G.nut yields are three times higher during summer than kharif due to ideal climate as clear sky, good light intensity and less incidence of pest and diseases.
It is also grow completely under
irrigation althrough the crop period.
Drymatter production is nearly 25.7 g/day as against 14.8 g/day in kharif.
Sowing period of mid – Dec. to mid-Jan is ideal for higher yield.
Seeds and sowing
Germination percentage less than 85 is not considered satisfactory
Selected pods are thoroughly cleaned, dried, packed preferably in gunny bags; stored in a well ventilated place.
G. nut pods for seed purpose are usually hand shelled about a week in advance of sowing.
The viability of seed will be lost if shelled long before seeding
Shellers are also used for shelling the pods to minimize the cost of groundnut production.
After shelling, shrivelled and damaged seeds are rejected by hand picking.
Seeds retained on 5mm sieve (100 Kernel wt. above 27g) germinates early and produce vigorous plants for high pod yield
Seed treatment against seed and soil born diseases is essential for stand establishment by preventing damage to seeds and seedlings emerging from soil.
Seed treatment with Thiram @ 3g/kg,
Bavistin (2g/kg) or DM – 45 (3g/kg) is effective for about 20days from sowing.
Most of the chemicals used for seed treatment against fungal bacterial diseases also affect Rhizobium, thus rendering the inoculation in effective for a short time.
When both seed treatment & inoculation are essential, seeds may be treated with fungicides & rhizobium culture is sprayed into seed rows & covered with soil.
Granulated Rhizobium strain may also be sown with seed in the furrows.
Seed rate and spacing
Cost of seed constitutes 37-50% of total cost of cultivation.
Method and depth of sowing
Groundnut seed can sown either by using mechanical or bullock drawn seed drill or by dropping the seed in plough furrow behind the country plough. Hand dibbling is also adapted to a limited extent.
drilling or dropping seed in plough furrows at 5 -7 cm soil depth.
Rabi & summer
Dropping seed in plough furrow at 4 – 5 cm soil depth.
In light, soils, the seeds are sown to a depth of 5 -7 cm and in heavier soils to a depth of 4 cms
For every tonne of pods about 63 N, 11 P2O5, 46 K2O, 27 cao and 14 Mgo kg/ha are removed by the groundnut crop.
A balanced fertilizer programme with particular emphasis on p, k, ca; mg is essential for opt. yield.
Apply 10t well decomposed FYM and incorporate it into soil just before the onset of monsoon.
The necessity for fertilizer nitrogen to groundnut is reduced because of being a leguminous crop,
it fixes atmospheric ‘N’ into the soil with root nodules. Around 200 kg N/ha can be fixed under ideal conditions.
In general, 20 kg N/ha – entire dose as basal is recommended for rainfed G.nut
30 Kg N/ha – in 2 equal splits at seeding &; 30 DAS – irrigated crop.
However the nitrogen fixation process of plant starts working at about 20-30 days after sowing, when the nodule apparatus is fully formed.
Till that time to meet the requirement for plant growth, an initial boost as starter dose of 10 kg/ha is necessary for rainfed groundnut.
Depending on the number of nodules, another 10 kg/ha at 30 DAS can be top dressed depending on the rainfall.
Nitrogen should be preferably applied in the form of Ammonium Sulphate as it also supplies the sulphur.
The total amount of ‘P’ uptake by groundnut plant is relatively small compared to N &; K.
It promotes root growth and multiplication of Rhizobium.
Opt. doses are
Rainfed – 40 kg P2O 5 /ha irrigated – 50 kg P2O5/ha
Entire dose should be applied at sowing along with N by placement preferably using ferti seed drill.
Single super phosphate is the best source as it contains 16% P2O5, 19.5% Ca &; 12.5% Sulphur along with some traces of Zn & other micronutrients traces. Therefore response to SSP is higher than
with DAP at equal nutrient basis.
Phosphobacteria as Pseudomonas striata and Bacillus polymixa solubilises the native phosphorus
and records 13-20% increase in groundnut yield.
Mychorhizal fungi inoculations have been beneficial in field tests in India
As most of the Indian soils are rich in K, groundnut in general will not show any significant response to applied potassium.
There is no necessity for potassium application to rainfed gr oundnut yielding around 1 t/ ha.
Response is observed only when the available potassium in soil is 150 kg/ha.
For rainfed groundnut – 40 kg/ha
For irrigated crop – 50 kg K2O/ha provided N is applied at recommended rate. Calcium and ;
These two nutrients are absorbed by pegs and developing pods and the common source of supply is gypsum.
Adequate calcium is essential in root and pod zones for yield and quality of kernels.
Calcium deficiency leads to unfilled pods called pops and darkening of plumules of embryo.
Sulphur is highly essential as it is directly involved in the biosynthesis of oil.
It improves nodulation of Rhizobium and prevents the premature leaf fall & increase the pod & oil yield.
Ca & S are supplied to crop through cao or gypsum & it has been observed to increasebthe yield by more than twice depending on its availability in the soil.
About 1 meq / 100 g soil in the root zone depth and 3.0 meq/100g soil in pod zone are threshold values for calcium sufficiency.
About 100 ppm of heat soluble sulphur is the critical limit of availablebsulphur for groundnut.
Gypsum application @ 500 kg/ha near pegging zone as top dressing at flowering (30 DAS) appears to be ideal .
If heavy rains occur within 2 weeks after application then a second lighter application of gypsum is necessary around 3weeks after first application.
K: Ca: Mg ratio
Groundnut is sensitive to imbalanced nutrient supply. The K:C:Mg ratio is more important than the total amount.
Increase in conc. of Mg in nutrient solution decrease K uptake by G. nut & also decreases Ca uptake.
There is a mutual antagonistic effect on the uptake of K, Ca & Mg.
The ideal ratio is 4 : 4 : 2 of Zinc, Boron and Iron
Zn def. is common on sandy & sandy loam soils.
The critical limit of available Zn in soil is 0.6 ppm.
Application of Znso4 @ 2 kg /ha once in 2 years corrects the deficiency.
If it is observed in standing crop, foliar application of 0.2% ZnSO4 along with 0.2% lime can correct the deficiency.
‘B’ def. leads to HOLLOW HEART. Deficiency has been reported in light soils of Punjab & T.N.
The threshold level of boron is 0.25 ppm.
Deficiency can be corrected by soil application of 5–10 kg/ha of boron.
In standing crop, corrected by 0.1% borax spray.
Iron chlorosis is largely due to its reduced availability in the soil. Immobilization of iron in the soil may be due to high levels of lime, high PH (>7.6) or high levels of bicarbonates in soil or irrigation.
Spraying of ferrous sulphate mixed with 1% of ammonium citrate around 50 DAS corrects iron Deficiency.
Weed competition is critical upto 35 DAS.
Yield losses may be to the extent of 70%. , especially under rainfed conditions.
When once pegging begins (40 DAS ), there should not be any disturbance to pegs through
manual or mechanical weeding.
Important weed flora in the groundnut crop are
Cyperus rotundus ; chloris barbata, celosia argentena, commelina benghalensis, Boerhaavia diffusa etc.
Hand weeding is done twice, first around 20 DAS & 2 nd at about 35 DAS.
Inter cultivation usually starts around 10 days after emergence and; continues upto 35 DAS at 7 – 10 days interval till pegging begins.
Cost effective weed management under rainfed conditions is, repeated intercultivation (harrowing) upto 35 DAS followed by hand weeding.
Use of herbicide
A mixture of oxadia zon &; Dinoseb each @ 1.7 kg /ha gives excellent control of weeds besides reducing stem rot in G.nut.
Fluazifop (150 – 250 g) is a promising post herbicide for controlling grasses, particularly cynodon dactylon, 35 – 40 DAS
IWM involving the above two appears most effective & ; economical, provided the crop is not subjected to prolonged drought or soil moisture stress during the crop
Pre-plant incorporation of Fluchloralin @ 1.25 – 1.5 kg/ha
Pre-emergence application of Pendimethalnin @0.6-1.5 kg/ha or Alachlor @ 1.5-2.0 kg/ha.
Groundnut crop is mostly cultivated during kharif under rainfed conditions.
Irrigated groundnut accounts for over 20% of the total area under the crop in the country & it yields around
The period from peak flowering to early pod development (45 – 75 DAS) is the most sensitive to soil moisture stress. In other words, flowering, peg penetration and pod
development stages are the 3 moisture sensitive stages for pod yield.
Very early growth phase (upto 20 DAS) is least sensitive.
Scheduling of irrigation:-
On sandy loam soils, scheduling irrigations at 25% DASM throughout the growth period results in high pod yield.
Irrigating the crop at 25% DASM – from pegging to early pod development
50% DASM – at other stages appear to be ideal for high WUE without significant reduction in pod yield.
An IW/CPE ratio of 1.0 at moisture sensitive stages and 0.6 during other stages leads to high WUE.
The water requirement of groundnut, on an average., ranges b/n 450 & 650 mm &; WUE is 0.6 to 0.8 kg /m
If irrigation water is not limiting , then a total of 8 irrigations are adequate for optimal yield.
pre –sowing irrigation followed by an irrigation at 25 DAS, 4 irrigations at 10 days interval & final two irrigations at 15 days interval.17
At times of deficit supplies, an irrigation at 25 DAS followed by 2 at 15 days interval b/n 45 &; 75 DAS appears to be minimum requirement &; it can minimise yield losses due to soil moisture stress.
The first irrigation is given at 25 DAS to create moisture stress in the soil which is desirable to get the good root system, to reduce excessive vegetative growth, Encourage the better nodulation, Induce heavy flowering in a single flush (synchronous flowering)
Method of Irrigation
The crop is usually irrigated by check basin method. Border strip is more suitable than other methods
Sprinkler irrigation is ideal for g. nut crop on sandy soils
The groundnut crop is predominantly raised as intercropping or sequence cropping depending upon the type of
Component crop & Rainfall distribution.
In general, g. nut crop is rotated with cereals commercial crops and oilseed crops.
Yield of cereals following g. nut is usually increased by 25%.
Important cereal crops grown with g. nut are pearlmillet, sorghum & maize.
Other long duration crops grown with g. nut as intercrops are pigeonpea, cotton and castor.
short duration intercrop with g. nut are sesame, sunflower, cowpea, green gram, black gram like
G. nut + pigeon pea ‡ 7:1 to 15:1 + Cowpea ‡ 6:1 + Castor ‡ 5:1, 7:1 + Pearlmillet ‡ 3:1.
Generally bunch and semi- spreading type comes to maturity by 100 – 105 days where as spreading type it is 125 -135 days.
The prominent symptoms of maturity are
Yellowing of leaves
Necrotic spotting on the leaves
Dropping of older leaves / leaf fall.18
The pods become very hard & tough, they give cracking sound when split open with fingers.
The inside of the shell turning dark, with netted venation
Seed coat develops pink or red colour (normal colour of the varities)
Raising of the soil to the base of the stem is observed .
Generally harvesting is done by pulling or lifting the plants from the soil with pods intact.
If soil moisture is adequate, then hand pulling. If soil is dry, tractor or bullock drawn blades are used for lifting the vines with pods.
Harvesting before maturity reduces yield & oil % & seeds are highly susceptible to afflotoxins.
If delayed, results in increased incidence of stem rot, weakening of
Gynophore/peduncle & some of the pods may remain in soil itself at the time of harvesting.
The process of separating pods from haulms in bunch type, if vines are still green, plants is knocked against a cross bar to dislodge the pods.
The most common method is stripping pods with hand.
At the time of harvest, pods usually have moisture content around 40 – 50% and hence need to be dried to 10% moisture content for safe storage.
Drying should be done rapidly to prevent fungal moulding
Sun drying is the usual method of drying.
Summer g. nut should be dried in shade to prevent loss of viability, if it is for seed purpose.
Storage at farmer level is invariably in the form of pods. Farmers usually dispose of groundnut pods within a month from drying yard itself.
A few store it for 6 months (till kharif seeding) in anticipation of high price.
Pods for seed purpose are stored for 7 – 8 months.
Pods for seed purpose are stored in earthern pots, mud bins or bamboo baskets or Gunny bags having polythene lining
If the seed moisture content is above the critical level of 9% then Aflatoxin production due to Aspergillus flavus just before the post – harvest drying & mould growth at later stage takes place.
Groundnut kernel yield is the product of pod number, number of kernels per pod and weight of kernels
Kernels per pod vary from 1-5, pods per plant from 5-105 and 100 kernel
Weight from 28 – 62 g (ICRISAT 1987).
There is a high positive correlation between the number of mature pods and pod yield.
Rainfed: – 10 – 15 q/ha
Irrigated: – 20 – 25 q/ha.
The harvest index in groundnut varies between 0.35 and 0.50 in groundnut.
Quality of groundnut is largely determined by volume weight of pods, shelling %,
100 kerenel weight, oil content, free fatty acid content, colour of pods & testa colour.
1) Volume weight of pods
It is the wt. per unit vol. of pods, which indicates maturity & development of kernels when the pods are disposed by volume.
Small pods have high volume weight than those of bigger pods
The average 100 pod weight varies from 73g (7 MV – 2 , Spanish bunch) to 107 g (M -13- virginia runner)
Volume weight is influenced by rainfall distribution at pod development & Ca & S in pod zone.
2) Shelling percentage
Shelling – separation of kernels from pods.
It is the % of kernels to pods by weight.
It ranges from 68% in M13 to 76% in TMV-2.
Irrigated crop has lower shelling % than that of rainfed crop
It depends on thickness of the shell, development of kernel & following pattern during the crop period.
It is influenced by genotype, Rainfall distribution & Ca in pod zone.
3)100 Kernel weight
It is an indication of proper kernel development.
Average 100 kernel weight ranges from 30 g (TMV 2) to 78 g (in M13).
It is a varietal character with marginal influence of Rainfall distribution, nutrient management &
Ability of translocation of photosynthates from source to sink.
4) Oil content
It generally ranges from 48 – 51 %
It depends on temperature during first 3 weeks of pod development, maturity of kernels which is influenced by Rainfall during development stage & ‘S’ content in soil root zone.
Virgina runners have higher oil content than Spanish bunch types.
5) Oil quality
The free fatty acid content in oil will decide the shelf life of oil. Higher the free Fatty acids content lesser is the quality & faster is the deterioration of oil quality.
Oil extracted from runner type have best quality due to higher concentration of Tocopherol
The ratio of saturated to unsaturated fatty acid also decide oil quality.
The ratio of oleic acid to linoleic acid should be 1.6 to have long shelf life.
Colour of pods and testa of kernel
Attractive colour of the pod & testa gets higher price in the markets especially for direct consumption.
In general, light golden yellow colour of pods are preferred & fetch more price in market.
Kernels with pink, rose or light brown testa are preferred
For easy marketing of pods & kernels the grading is done. Pods are graded into 3 categories and kernels into 4 categories based on size.
Pods and kernels
G.nut oil cake are exported to other countries.
But in recent years export of these products are drastically reduced due to increase afflatoxin load in the products and increasing demestic demand.
China is the largest exporter of kernels followed by USA & India.
G. nut cake is a good veg. protein & poultry feed.
India is exporting large quantity of
GN cake in western countries till 1980. Later on the export of G.nut cake was significantly reduced due to higher levels of alfatoxins