Scientific name: Arachis hypogaea Linnaeus
Varietal Selection for Groundnut
A number of promising varieties have been evolved in various groundnut growing states for commercial cultivation. Description of some of the important varieties is given below:
It is a bunch type of variety which was released for general cultivation in 1964-65. It matures in 100-105 days. It is suitable to grow in rainfed conditions. It is susceptible to tikka disease. It has 70 per cent shelling out turn and 49 per cent oil content. It has a yield potential of 15-20 quintals per hectare.
It is a bunch type of variety which was released for general cultivation in 1973. It matures in 95-100 days. It is recommended to grow under rainfed condition. It is susceptible to tikka disease. It has 70 per cent shelling out turn and 50 per cent oil content. Its yield potential is 15-20 quintals per hectare.
It matures in 115-125 days. Plant height is 23-18 cm. It has two seeded bold pods. Seeds are of medium size and of brownish rose colour. Its seeds contain 43.75 per cent oil and shelling percentage is 76. It has a yield potential of 17 to 20 quintals per hectare.
Kadiri-3 (Robout -33-1):
It matures in 100-110 days. Plants are smaller in size and bear pods close to root zone and can be easily uprooted by hand pulling. It bears two seeded pods. Seeds are purple in colour, medium sized and oblong in shape. Its seeds contain 44.7 per cent oil. Its shelling out turn is 72 per cent. Average crop yield is about 17-20 quintals per hectare.
It is a spreading variety. It matures in 135 days. It is suitable for rainfed conditions. It has 74 per cent shelling out turn and 50 per cent oil content. It is partially drought resistant. Its yield potential is 14-18 quintals per hectare.
It is a bunch type of variety with green foliage. It matures in 105 days. It is suitable for both rainfed as well as irrigated conditions. It has a 77 per cent shelling out turn and 49 per cent oil content. Its yield potential is 12-16 quintals per hectare.
It is a bunch type variety which matures in 105-110 days. It yields about 15-20 quintals per hectare. It has 72 per cent shelling out turn and 48 per cent oil content.
Composition & Uses
Among the oilseed crops, groundnut has first place in India. Groundnut oil is primarily used in the manufacture of vegetable oil (vanaspati ghee). Groundnut seed contains about 45 per cent oil and 26 per cent protein. Groundnut kernel as a whole is highly digestible. It is, in the first place about as concentrated a food as money can buy, one gram for supplies 5.8 food calories. This compares with 4.0 calories per gram for sugars, 3.5 calories for whole wheat, 2.6 calories for bread. The biological value of groundnut protein is among the highest of the vegetable protein, and equals that of casein. Groundnuts are a good source of all B vitamins except B12. They are a rich source of thiamin, riboflavin, nicotinic acid and vitamin E. However, they lack in vitamin A. With regard to minerals, phosphorus, calcium and iron are present in significant amount. The kernels are consumed either roasted or fried and salted.
The oilcake obtained after the extraction of the oil is a valuable organic manure and animal feed. It contains 7-8 per cent nitrogen, 1.5 per cent phosphorus and 1.5 per cent potash. It is a good rotation crop, it builds up the soil fertility by fixing atmospheric nitrogen through the root nodules and also an efficient cover crop for lands exposed to soil erosion.
Groundnut is essentially a tropical plant. It requires a long and warm growing season. The most favourable climate conditions for groundnut are a well distributed rainfall at least 50 cm during growing season, abundance of sunshine and relatively warm temperatures. It seems that plant will grow best when the mean temperature is from 21-26.5°C. Lower temperatures are not suitable for its proper development. During ripening period it requires about a month of warm and dry weather.
Groundnut thrives best in well-drained sandy and sandy loam soils, as light soil helps in easy penetration of pegs and their development and also harvesting. Clay or heavy soils are not suitable for this crop, as they interfere in penetration of pegs and make harvesting quite difficult. Groundnut gives good yields in the soil with pH between 6.0-6.5.
Rotations and Mixed Cropping
Groundnut is grown in rotation with wheat, gram, pea, barley, etc. It is grown as a mixed crop with bajra, maize, jowar, castor and cotton. Groundnut can also be followed by safflower where early varieties are grown and moisture remains in the soil at the time of harvest.
Although groundnut is a deep-rooted crop but looking to it’s under ground pod forming habit, deep ploughing should be avoided. Because deep ploughing encourages development of pods in deeper layers of soil which makes harvesting difficult. One ploughing with soil turning plough followed by two harrowings would be sufficient to achieve a good surface tilt up to 12-18 cm depth. One or two summer cultivations will minimize weeds and insect-pests to a great extent in problem areas.
Seed and Sowing
Selection and Treatment of Seed:
Quality of seeds is of utmost importance for establishing the optimum plant stand. Pods for seed purposes should be stored unshelled in a cool, dry and ventilated place. For seed purposes, pods should be shelled by hand one week before sowing. Hand shelling ensures little damage to seeds. Pods shelled long before sowing time are liable to suffer from loss of viability and storage damages. Discard very small, shriveled and diseased kernels. Only bold seeds should be used for sowing. Treat the selected kernels with 5 g of Thiram or Captan or Ceresan per kg of kernels so as to check various seed and soil borne diseases. Seed should be inoculated with proper strain of Rhizobium culture particularly in those places where groundnut is to be grown for the first time.
Time of Sowing
Sow the rainfed crop with the advent of monsoon in the last week of June or in the first week of July. Complete the sowing as early as possible as delayed sowing causes progressive reduction in the yield. Where irrigation facilities are available, sow groundnut around 20th June or 10-12 days before the onset of monsoon with a pre-sowing irrigation. This helps in best utilization of monsoon by the crop because all the germination will take place before rains start which ultimately result in a higher yield. It will also help in getting the field vacated in time for the sowing of Rabi crops. In southern part of the country where groundnut is sown in Rabi season also, it should be sown in the month of November and December.
Spacing, Seed Rate and method of Sowing
In bunch types, the row to row distance is kept 30-40 cm and in spreading types 45-60 cm. For this, 80-100 kg of seeds per hectare would be enough for bunch types and 60-80 kg for spreading types. Plant to plant distance would be 15 and 20 cm for bunch and spreading type’s respectively. Sowing should be done about 5 cm deep behind the plough or with the help of dibbler or seed planter. On a large scale, seed planter can be used.
Manures and Fertilizers
Just like the other legumes, groundnut meets the major part of nitrogen requirement through the nitrogen fixation. However, an application of 20-40 kg nitrogen per hectare as a starter dose is given to meet the nitrogen requirement of the crop in the initial stage in poor fertility soils. If farm yard manure or compost is available, 10-15 tonnes may be added per hectare about 15-20 days before sowing. If nitrogen is to be applied through fertilizer, prefer ammonium sulphate. It provides sulphur in addition to nitrogen. The soil should be tested for the availability status of phosphorus and potassium and fertilizer recommendations for groundnut are obtained. In the absence of soil test, it would be advisable to apply about 50-60 kg P2 O5 and about 30-40 kg K2O per hectare to meet the requirement of the crop. Phosphorus should be applied preferably through superphosphate. The fertilizer should be placed at the time of sowing about 4-5 cm in the side of the seed and 4-5 cm below the seed level. Calcium too has pronounced effect on proper development of pods and kernels. Therefore, care should be taken to ensure that soil has sufficient calcium. Apply gypsum at the rate of 125 kg hectare.
Being a rainy season crop, groundnut does not require irrigation. However, if dry spell occurs, irrigation may become necessary. One irrigation should be given at pod development stage. The field should be well drained. In the southern part of the country where groundnut is grown in Rabi season too, three to four irrigations are necessary. Give the first irrigation at the start of flowering and the subsequent irrigations whenever required during the fruiting period to encourage peg penetration and pod development. The last irrigation before harvesting will facilitate the full recovery of pods from the soil.
Weed Control and Earthing
Normally, one or two hand hoeings and weedings should be done, depending upon soil type and extent of weed infestation. First hoeing should be done three weeks after sowing and the second, three weeks thereafter before commencement of flowering. Care should be taken that soil should not be distributed at pod formation stage. Weeds can also be controlled effectively by the application of TOK-E-25 at the rate of 4 litres dissolved in 600 litres of water as pre-emergence spray. Basalin at the rate of 1kg a.i. per hectare dissolved in 800-1000 litres of water can also be used as pre-planting spray. The earthing up should also be taken simultaneously with intercultural operations. Basic idea of earthing up is to promote easy penetration of pegs in soil as also to provide more area to spread.
Harvesting and Threshing
It is necessary to dig the pods at the right time for obtaining higher yields of pods and oil. Nut takes two months to attain full development. A fully mature pod will be difficult to split easily with finger pressure. This stage is achieved when vine begins to turn yellow and leaves start shedding. Harvesting should be done when good percentage of nuts is fully developed and fairly intact. In case of bunch type of groundnut, the plants are harvested by pulling. Harvesting of spreading type of groundnut is done by spade, local plough or with the help of blade harrow or groundnut digger. Leave the harvested crop in small heaps for two three days for curing. After curing, collect the crop at one place and detach the pods either by hand or using groundnut plucker for separating the pods from the plants.
By adopting the above mentioned agronomical practices, it will be possible to obtain about 15-20 quintals of pods per hectare from bunch type varieties and 20-30 quintals per hectare from spreading varieties.