• Groundnut is energy rich crop but it is grown under energy starved conditions. The nutritional needs of the groundnut must be satisfied to attain maximum yields. An average crop of groundnut yielding 1900 kg/ha removes about 112 kg N, 27 kg P₂O₅ and 34 kg K₂O from one hectare of land.
• It is reported that the groundnut plant has a universal ability to utilize soil nutrients that are relatively unavailable to other crops and is very effective in extracting nutrients from sandy soils of low nutrient supply
• For obtaining higher yields through proper utilization of fertilizers, the following points should be kept in mind.
• Application of right quantity of nutrients
• Choice of right sources of fertilizers to supply the required nutrients.
• Application at right time by adopting proper methods

• Nitrogen is an essential constituent of proteins and chlorophyll and is present in many other compounds of great physiological importance in plant metabolism.
• It imparts dark green colour to plants. It promotes leaf, stem and other vegetative growth but retains small root system.
• Groundnut is a leguminous plant, which fixes atmospheric nitrogen in the root nodules and thereby the demand for applied nitrogen reduces. The contribution of biologically fixed nitrogen to the total nitrogen requirement of plant has not been completely quantified.
• There are indications that under optimum conditions groundnut plant can fix atmospheric nitrogen to an extent of 200-260 kg nitrogen/ha, eliminating or reducing the need for application of fertilizer nitrogen.
• The quantity of nitrogen to be applied depends upon the fertility of the soil, plant population, rainfall distribution, other nutrients available and contribution from symbiotically fixed nitrogen.
• Ammonium sulphate is a better source of nitrogen than urea because it also supplies sulphur to plant. Nitrogen application may be necessary in the acidic soils where functioning of rhizobia may be hampered.
• To ensure good nitrogen supply, water logging should be avoided. In well-drained soils, oxygen is available to roots for respiration. This improves the ability of roots to absorb nitrogen from soil and for rhizobia to fix more nitrogen.
• It has been observed that the pod yield of groundnut increased only with judicious combination of N and P rather than application of single nutrient.
• The following nitrogenous fertilizers are commonly used in groundnut crop.

• TIt is the oldest N-synthetic fertilizer. It contains about 20%N in ammonium form and is a white crystalline salt. It is readily soluble in water but only slightly hygroscopic. It has a strong acidifying action on the soil.
• Among the available nitrogenous fertilizers, ammonium sulphate is preferred for groundnut crop because of its sulphur content (24%). It can be used in both rainfed and irrigated conditions. In top-dressing also, it can be used before irrigation or after irrigation at the time of proper soil condition.

• It is a white granulated organic compound and contains 46% N. Urea is easily soluble in water (1.0 kg/ lit at 20°C) having low specific weight (bulk density, 0.7 kg/lit).
• Urea is very popular and commonly used in groundnut. It can be applied as basal-dressing in rainfed as well as irrigated conditions, but while top-dressing it should be applied at optimum soil moisture followed by harrowing.
• Loss of gaseous ammonia may occur under certain conditions (high soil reaction and temperature) after applying the fertilizer on the soil surface.

• It is granulated white (sometimes green or brown) water-soluble inorganic compound and contains 26% N. Due to Ca content it is an important fertilizer for groundnut crop.
• It is easily available to the plant root. It can be used in basal application as well as in top-dressing. Top-dressing should be done after irrigation at proper soil moisture.
• Split application of nitrogen is beneficial compared with the basal application of entire nitrogen for increasing pod yield of groundnut. Split application of fertilizers may be advantageous on light soils in areas with high intensity rains.
• Method of placement of fertilizer is either broadcasting or placement in the row. When low doses of fertilizer are used, it is best as side-dressed in the row.

• IPhosphorus is a constituent of nucleic acid, phytin and phospholipids. An adequate supply of phosphorus early in plant life is important in laying down the primordia for the reproductive parts of the plants.
• Phosphorus is also an essential constituent of majority of enzymes. It stimulates early root development and growth, thereby helping to establish seedlings quickly.
• It also stimulates flowering and aids in seed formation. It enhances the activity of rhizobia and increases the formation of root nodules.
• It helps in fixing more of atmospheric nitrogen in root nodules.
• With phosphorus deficiency, plants may simultaneously suffer from nitrogen as well as potassium deficiency.
• Excess of phosphorus may cause in some cases trace element deficiencies (particularly iron and zinc) but may at times alleviate the detrimental effects of over-liming.
• The total amount of phosphorus taken by the groundnut plant is relatively small as only 0.4-0.5 kg of available phosphorus is required to produce one quintal of pods. Though the amount of phosphorus required is small, large quantity of fertilizer has to be applied, as the efficiency of uptake of phosphorus from fertilizer is low.
• Groundnut can use phosphorus at the lowest levels than most crops. The groundnut plant is also able to grow normally with low levels of available soil phosphorus probably because of the formation of mycorrhizal association of the roots with soil fungi or due to phosphobacteria in the rhizosphere of the plant making unavailable phosphorus available to the groundnut plant.
• The plants grown on soils with acute phosphorus deficiency show severe stunting, leaf curl and pink or violet veination (from accumulation of anthocyanin pigments) on the stems and undersides of leaves.
• The plants however, recover when roots go deep and tap more soil. Mild symptoms of phosphorus deficiency are expressed as greener than normal leaves and stunting of plants.
• The most common source of phosphorus is single superphosphate (SSP) which contains calcium (19.5%), sulphur (12.5%) and phosphorus (16.0%). It also contains zinc and magnesium in traces.
• Response of groundnut is higher to single superphosphate application than to diammonium phosphate (DAP) because of presence of Ca, S and trace elements in SSP. * Phosphorus when applied as single superphosphate starts becoming available within 15-20 days after application if the soils are moist. The best availability of phosphorous is at pH 6.5.
• Soils should receive phosphatic fertilizers each year to build up the phosphorus level.
• Application of single superphosphate and diammonium phosphate was most effective for groundnut when applied at planting than top dressing. This should be mixed with soil just before the final land preparation. Alternatively, it can be applied in seed furrows before sowing.
• The reason for the popularity of DAP as a source of phosphorus is because it is available in granular form and so is easy to apply.
• Sources of phosphatic fertilizers commonly used in groundnut.

• It is the most commonly used phosphatic fertilizer in groundnut. It contains 16% P₂O₅ besides calcium (19.5%) and sulphur (12.5%). The P content of this fertilizer is more than 90% water soluble and thus acts immediately.
• Single superphosphate should be used as a basal-dressing only by placement method. It is not suitable for foliar spray as it contains some amount of gypsum and diphosphate which are not easily soluble in water.

• It is very popular granular fertilizer having both nitrogen (18%) and phosphorus (46% P₂O₅). Nitrogen content of this fertilizer is in ammoniacal form, and is thus immediately available to the plant root. Similarly all P content is water soluble and becomes available immediately.
• Application of di-ammonium phosphate (DAP) to the soil should be done before sowing as a basal-dressing. To minimize the fixation of P, it should be applied in furrows through placement. However, due to its high solubility in water, it may be used as foliar spray also.

• It is a concentrated form of superphosphate containing 46 to 50% P₂O₅. It is granulated, grey in colour and easily soluble in water.
• Triple superphosphate should be applied before sowing by placement method. While applying to the soil it should be placed closer to the root zone so that it becomes readily available to the root. However, it can be used for foliar spraying, as the phosphorus content is high.

• Potassium is needed by the groundnut crop from early stage of its growth to maturity.
• It imparts increased vigour and disease resistance to plants.
• It regulates water conditions within the plant cell and thus reduces tendency to wilt and helps in better utilization of available water.
• It helps in formation of proteins and chlorophyll.
• It acts as an accelerator of enzymes action.
• It counteracts the injurious effects of excess nitrogen in plants.
• A balanced ratio of nitrogen and potassium is important in plant nutrition.
• Response to application of potassium can be expected only when available potassium in the soil is less than 126 kg/ha.
• There is a mutual antagonistic effect on the uptake of potassium, calcium and magnesium. The ratio K:Ca:Mg is more important than total amount of any of them.
• Response to applied potassium is not often obtained in Indian soils as they are medium to high in potassium content and also due to antagonistic effects or deficiencies of other plant nutrients.
• The plants grown on deficient soils express symptoms of potash deficiency on the older leaves, the margins of leaflets start yellowing.
• This is usually followed by interveinal chlorosis and finally necrosis of the leaves, beginning at the margins and proceeding inwards until the leaf fall off. The youngest leaves are most affected.
• A dose of 50-100 kg of muriate of potash just before final seed bed preparation may be advantageous in areas where potash is deficient.
• A high concentration of potassium in the fruiting zone is harmful because it affects pod quality, especially at low levels of calcium.
• With regard to method and time of application, the results revealed that the split application of potash is not advantageous.
• Following potassium fertilizers are used in groundnut crop.

• It is a white or slightly coloured, granulated, water-soluble fertilizer having 60% K₂O. When applied to the soil it is readily available to the plant root. Entire quantity of fertilizer may be applied to the soil prior to or at planting time.
  

• It is a common fertilizer for groundnut which contains sulphur besides 50% K₂O. Due to its sulphur content, potassium sulphate is a better fertilizer for groundnut than potassium chloride.
• The K component is water-soluble and therefore, is readily available to the plant roots. It can be used either as basal dressing or top dressing.
• The application of potassium sulphate, generally, will be more appropriate in soils which are calcarious in nature and alkaline in reaction.
• Under wet conditions, it is preferable to apply potassium sulphate than potassium chloride, as leaching of potassium sulphate will be less. Similarly, potassium sulphate will be more effective on light and medium soils than on heavy soils.
• It is indicated the need for balanced fertilization with NPK. Combined application of 10-40 N, 10-30 and 20-40 K kg/ha was optimum for groundnut.
  

• Calcium requirement of the groundnut plant is quite heavy.
• Availability of this nutrient in the soil in adequate quantities is very essential for meeting the nutritional requirements of the crop, especially in the case of acidic soil. Even in neutral and alkaline soils of sandy texture, calcium deficiency may become serious. * It is required for good growth, improvement in the quality of nuts as evidenced by thin strong shell besides well-filled pods.
• Calcium functions both to control pH and as an essential element. The calcium absorbed through roots or tops do not translocate to pods.
• Moderate calcium deficiency appears first on fully developed leaves as localized pitted areas on lower surface of leaves which subsequently develop into brown necrotic spots.
• Such spots may have outer chlorotic halo similar to that of Cercospora leaf spot. * Severe calcium deficiency results in chlorosis, wilting and death of terminal buds. * In pods it is expressed as unfilled pods, darkening of plumule of the seed embryo and reduced pod development.
• Empty pods, normally called `pops', are frequent in calcium deficient soils, particularly in acidic soils.
• Groundnut, being a legume and oilseed crop, its calcium and sulphur requirements are quite high. About 1 meq/100 g of soil in the root zone depth and 3 meq/100 g of soil in the pod zone (5 cm suface soil) are considered to be the threshold value of calcium sufficiency.

• Gypsum application is generally recommended because it provides calcium and sulphur, it has impurities that also provide magnesium.
• It reduces pH slightly, improves soil structure, creates a favourable environment for the microflora and reduces impact of drought and the associated aflatoxin problem. * Excess of gypsum does not harm the plants.
• It is relatively soluble source of Ca and, therefore, readily available to the developing pods.
• It is subjected to almost complete loss from the soil by the time groundnut crop is harvested. Higher quantities of gypsum than necessary are, therefore, applied at early flowering stage to ensure adequate calcium supply in the pod zone.
• Since there is little residual effect of gypsum it is necessary to repeat application every season.
• Groundnut has the unique characteristic of uptake of calcium and sulphur by the developing pegs and pods.
• As calcium is relatively immobile in plant tissues and is not translocated in sufficient quantities from the roots to developing pods, calcium and sulphur have to be made available in adequate quantities in pod zone.
• Gypsum should be finely powdered and applied by banding near the plants (pegging zone) and then stirred into the soil.
• Can also be applied to groundnut by dusting on the plant at the early flowering stage when it falls around the plant and reaches the pod zone.
• The best time for application is when plants are in the full bloom stage i.e., 40 to 45 days after sowing. The pod shall absorb calcium entirely from the soil.
• Application of gypsum @ 200 kg/ha as basal (at the time of sowing) and at pegging stage (on 45 DAS) is recommended to obtain higher yield in groundnut.
• Under rainfed situation top dressing of gypsum can be extended up to 60 days after sowing depending upon the rainfall and available soil moisture.
  

• Sulphur is an essential constituent of plant proteins and amino acids and can be absorbed by roots and more rapidly by pods.
• Sulphur is directly involved in the biosynthesis of oil and is usually deficient in the groundnut soils.
• About 10 mg/lit of heat-soluble sulphur is the critical limit of available sulphur for groundnut.
• Sulphur deficiency symptoms are difficult to separate from nitrogen deficiency symptoms except that sulphur deficiency is expressed first on younger leaves while nitrogen deficiency symptoms occur on older leaves or on the entire plant. Sulphur could be absorbed by the roots and fruits.
• Sulphur application increases pod yield, shelling percentage, protein, oil content, cysteic acid and methionine content of groundnut.
• Many treatments that are commonly applied to groundnuts supply sulphur.
• Single super phosphate contains 12.5% sulphur, gypsum contains 18.6% sulphur. * Dusting of elemental sulphur to control diseases also supplies sulphur. * Ammonium sulphate in place of urea as a source of nitrogen also provides sulphur and thus is preferable.

• Iron deficiency will be further exaggerated when higher plant density and rapid plant growth is ensured.
• For correction of iron deficiency, spray of ferrous sulphate (commercial grade) @ 10 g/lit of water on 30, 40 and 50 DAS is advised.
• Ferrous sulphate is quite cheap and is readily available. The ferrous ion will cause some phytotoxicity irrespective of the concentration is used. But this is of no great concern.
• The general practice is to tie the ferrous sulphate in muslin or ordinary cloth bag and soak this bag overnight in 10 lit of water. This stock solution is then diluted to the desired quantity.
  

• When zinc deficiency is noticed in the standing crop, foliar spray of zinc sulphate 0.5%, to which lime is added to make lime strength 0.5% (100 lit of water containing 0.5 kg of ZnSO₄ plus 0.5 kg of lime). Best results are obtained when the spray is given once or twice before pod filling starts (i.e., before 40-45 DAS).

• Boron deficiency usually causes hollow heart. The threshold value for boron is 0.25 ppm. Slight excess of boron leads to toxicity as iron uptake is inhibited resulting in typical burning of the leaf margin. Apply borax 10 kg along with gypsum on 45 DAS if deficiency is observed.

• Molybdenum is perhaps, the most `micro' of the micronutrients. Molybdenum is essential for rhizobia to function properly. When molybdenum is deficient, the bacteria cannot fix sufficient nitrogen for the plant, which then shows symptoms of nitrogen deficiency.
• Molybdenum becomes unavailable in acidic soils. Liming increases the availability of molybdenum.
• Fertilization with 25 g of sodium molybdate per ha rectifies the deficiency and ensures adequate nitrogen fixation by the crop.

• The ratio of K:Ca:Mg is more important than the total amount of any of them. Increased concentration of magnesium in dilute nutrient solutions decreased the uptake of potassium by groundnut. Similarly uptake of calcium was depressed by increasing the concentration of magnesium. There is a mutual antagonistic effect on the uptake of K, Ca and Mg.

• Mix 12.5 kg/ha of micronutrient mixture developed by Department of Agriculture with enough dry sand to make a total quantity of 50 kg/ha and then broadcast evenly on the soil surface immediately after sowing. Do not incorporate the micronutrient mixture in the soil.

• Organic manures are important primarily as humus fertilizers. Humus is decomposed by soil organisms providing them with nutrients and energy. Humus also improves soil fertility by improving physical and biological characteristics.
• Farmyard manure (FYM) and compost are mainly used as organic manures in groundnut crop. In addition to serving as a source of supply of nutrients, bulky organic manures like FYM serve as a source of organic matter which influences nutrient supply to plants in many ways.
• Organic matter improves the structure and reduces compaction and crusting of the soil. It is also required as a source of energy for nodulation and nitrogen fixation by microorganisms.

• It is the most important and commonly used organic manure, which is produced by the cattle, pigs and poultry. Low moisture holding capacity of the soil, quick drying and crust formations are the problems in the lateritic soils. The hardness of soil physically restricts the full development of pods. Addition of FYM considerably reduces these problems.
• Usually 12.5 t/ha of FYM is essential because its application will improve the porocity and structure of the soil and make it less sticky. It also provides most micronutrients.
• Addition of FYM should be applied well in advance (15 to 30 days before sowing) and should be incorporated into the soil by country plough or blade harrow. FYM, besides cowdung, contains stubbles, stalks and other crop residues.
• Spreading FYM in a thin layer making it moist and covering it with thin polyethylene sheet for a period of one month in the hot sun, may induce slow, moist heating of FYM and thus kill most of the harmful organisms.
• In many villages, biogas plants have become common. The cowdung slurry is a rich source of organic matter. In some parts, farmers add single super phosphate to the slurry before it is applied to the field.
• Application of enriched farm yard manure (750 kg/ha) for rainfed groundnut particularly for red lateritic soil will be highly useful for enhancing the root growth and development and thereby the pod yield.
• To prepare enriched farmyard manure, incorporate the recommended quantity of superphosphate (10 kg P₂O₅/ha) to the well-decomposed sieved FYM (750 kg/ha) and cure it for 1 month before application.
• FYM has several beneficial effects, on light and also on heavy soils, by improving soil structure and buffering capacity, water holding capacity, availability of micro nutrients and adding some nitrogen. However, FYM is difficult to obain. An alternative to FYM is to practice green manuring with crops like sunnhemp, daincha and other legumes or by sheep penning.

• Compost is a product of the decomposition of plant and animal wastes with various additives. Well-decomposed compost should be applied about one month before sowing. It may be broadcasted and incorporated into the soil with the help of country plough or blade harrow.
• Application of flyash (20.0 t/ha) alone and with fertilizers (STCR) and compost was also found to increase the pod and haulm yield of groundnut on lateritic soils.
  

• In modern agricultural practice various chemicals in solution or aqueous suspension are sprayed onto the foliage of crop plants. Foliar nutrition is a useful method of fertilizing certain crop plants that can tolerate the aerial spray without damage.
• The spraying of foliage with nutrients is a method used to deal with special problems that cannot be solved readily by application of chemical fertilizers to the soil.
• Foliar nutrition can serve as a means of applying supplemental nutrients during critical growth periods when it is impractical to apply fertilizers to soils. This process may offer a remedy in situations in which the time lag between soil application of fertilizers and plant absorption may be too long to satisfy the needs of fast-growing annual crops during periods of intense growth.
• Foliar nutrition may also serve as a means of applying micronutrients to crops. Although micronutrients can be supplied to plants by addition of chelated salts to the soil, such addition may not be very effective in some cases.
• In groundnut, foliar nutrient spray is advocated on 25 and 35 DAS. Nutrient solution required for one hectare is prepared with ammonium sulphate 1 kg + DAP (2.5 kg) + borax (500 g) and planofix (450 ml).
• This solution is sprayed during stray flowering (25 DAS) and peak flowering (35 DAS) stage, which will enable to synchronise flowering and more pod setting and kernel development.
• Wherever zinc and iron deficiencies occur, foliar spraying of ZnSO₄ (5 g/ lit of water) and FeSO₄ (10g/lit of water) respectively can be resorted to overcome the deficiencies.
• Spraying of cytocyme (0.5 ml/lit of water) at peg formation stage enhances the groundnut yield from 18.5 to 27.9 per cent. Foliar spray of Godrej Bumper @ 125 ml/ha at 40 DAS increases the pod yield of groundnut by 26.5 per cent.

• Continuous and unbalanced use of chemical fertilizers is leading to decrease in nutrient uptake efficiency of plants resulting in stagnation or decrease in crop yield. At the same time, the use of chemical fertilizers at a very high rate also leads to the problem of soil health deterioration, groundwater and atmospheric pollution.
• There are problems of losses in fertilizers after application through leaching, volatilization and denitrification of nitrogen and fixation of phosphorus in the soil.
• The effective use of biofertilizers along with other sources of plant nutrients is playing a vital role in increasing crop productivity.
• Biofertilizers are low cost, effective and renewable sources of plant nutrients to supplement chemical fertilizers.

• Supplement of chemical fertilizers as they contribute plant nutrients through biological nitrogen fixation and solubilization of fixed phosphate.
• Cheap so can help to reduce chemical fertilizer consumption.
• Enhance plant growth due to release of hormones, vitamins and auxins, etc.
• It is reported that 10-20% of crop yield can be increased with their use.
• Control and suppress soil-borne diseases as some of the inoculants produce antibiotics.
• Help in proliferation and survival of beneficial microorganisms of soil.
• Improve soil properties and sustain soil fertility.
• Help in mineralization of plant nutrients.
• Eco-friendly and pollution free because they contain only beneficial microorganisms.

• Broadly, the biofertilizers are classified into two types. The biological nitrogen fixing biofertilizers and the phosphate solubilising or mobilising biofertilizers.
• The nitrogen fixing biofertilizers consist of microorganisms which fix atmospheric nitrogen either symbiotically or asymbiotically into the plants.
• Phosphate solubilising biofertilizers have the ability to solubilise or mobilise the fixed insoluble phosphate of soil
  

• Rhizobium, soil bacteria have the ability to fix atmospheric nitrogen in symbiotic association with host legumes. These bacteria enter into the plants through root hairs, multiply there, form nodules and fix biological nitrogen in the nodules.
• To ensure effective nodules, the crop has to be provided with highly efficient Rhizobium in the vicinity of its root system. This can be achieved by artificially inoculating pre-selected effective and efficient Rhizobium.
• It is estimated that a well-nodulated groundnut under normal growth conditions is capable of fixing about 180 kg N/ha.
• Rhizobium inoculation is a cheaper and usually more effective agronomic practice for ensuring adequate nitrogen supply. Higher rate of Rhizobium inoculation is required to obtain sufficient nodulation of inoculant strain to overcome the competition by the native Rhizobium. Inoculum containing 105 cells/seed is the minimum requirement.
• An efficient strain of Rhizobium, TNAU 14 is recommended for groundnut. Seeds of groundnut required for one hectare are treated with 600 g (3 packets) of Rhizobium culture using rice gruel as a sticker. Care should be taken to avoid pealing of testa while seed inoculation.
• In the case of non-adoption of seed inoculation, apply 2 kg. (10 packets) of Rhizobium culture per hectare after mixing it with 25 kg of sand or farmyard manure at the time of sowing.

• Phosphorus is the next important nutrient for plant growth. Generally phosphorus is supplied to the plants in the form of chemical fertilizer and it has been observed that plants failed to utilize maximum part of the fertilizer.
• About 30 per cent of soluble form of phosphorus is available to the plants and rest is fixed in the soil in insoluble form. Phosphate solubilising biofertilizers have the ability to solubilise or mobilise insoluble phosphorus to the soluble form and then make it available to the plants.
• The efficient cultures have shown capacity to solubilise insoluble inorganic phosphate such as rock phosphate, tricalcium phosphate, iron and aluminium phosphate by production of organic acids.
• In acid soils, where the fixation of phosphorus is high, application of phosphatic fertilizers will be highly beneficial. This phosphobacteria is recommended both as seed and soil application to groundnut.
• For one hectare seeds, 600 g of phosphobacteria is used as seed treatment. For soil application 2 kg of phosphobacteria is applied after mixing it with 25 kg of sand or FYM.

• As the nitrogen fixation is a sensitive process the environmental factors like soil type, temperature, light and agronomic practices determine the success of inoculation. * Nodulation and nitrogen fixation show rapid decline under drought conditions. * Survival of Rhizobium under waterlogged conditions is reduced which leads to poor nitrogen fixation.
• Proper soil moisture should therefore be maintained for effective nodulation. Proper land preparation and addition of organic mater should be ensured for good plant growth and efficient nitrogen fixation.
• Low or high pH directly or indirectly affects the success of the Rhizobium inoculation, either by inhibiting the growth of Rhizobium or by making the nutrients non-available to the plants.
• Soil amendments as recommended should necessarily be used to correct the situation.
• Soil nutrients both major and minor, not only contribute to the growth of plants but also to nitrogen fixation. Hence application of nutrients must be made based on the soil-test values.
• Always treat the seeds in shade.
• Do not expose the treated seeds to direct sun rays.
• Use only specified Rhizobium meant for specific legume.
• Treat the seeds immediately or just 2-3 hours before sowing.
• Do not mix any chemical fertilizers and pesticides directly with inoculant.

• The complementary use of chemical fertilizers, biofertilizers and organic manures is referred to as `Integrated Nutrient Management' (INM). This will help to solve the problem of nutrient supply and soil productivity.
• The INM involves the intelligent use of organic, inorganic and microbial sources so as to sustain optimum yields and to improve or maintain soil chemical, physical and biological properties.
• To provide crop nutrition packages, which are technically sound, economically alternative, practically feasible and environmentally safe.

• Incorporation of haulms of groundnut crop after harvesting the pods adds substantial quantity of nutrients especially nitrogen with improvement in the organic matter level to a certain extent.
• When groundnut shells are added to soil after shelling of pods, it improves the soil fertility, water holding capacity, porosity and finally serves as mulches.
  

Use of hormone was not very much practical in the past but with the advancement of the production technology now application of certain hormones has become a common practice. Seeding the growth behaviour of the crop we find that groundnut usually suffers from two drawbacks--the first is that the crop being non-determinate keeps on flowering and production of pegs simultaneously uptil maturity and the second is that the pods start germinating at once after reaching physiological maturity, if they get water. As a result and effective pods germinate if there is rain or irrigation. Thus both the conditions lead to very poor yield and quality of the crop.

Application of L-NAA in the form of planofix (manufactured by May & Baker Ltd.) and Vaardhak (manufactured by Paushak Ltd.) at the time of flowering have been found to reduce the excessive vegetative growth and flowering period which ultimately increases the number of effective pods / plant, test weight and the yield/unit area. However, their positive effect on quality is not established. It has also been observed that their two applications at lower concentration are better than one application at higher concentration. The most ideal time for hormone application in groundnut is 40 and 80 days after sowing and the best concentration is 20 ppm.

• Foliar spray of mepiquat chloride 125 ppm enhanced the pod set and pod yield in groundnut.
• Soaking seeds in 100 ppm ethrel enhanced the germination in groundnut.
• For inducing dormancy in groundnut preharvest spray with 5 per cent Prosopis pod extract is found useful.
• Foliar spray of Brassinolide at 0.5 ppm at flowering and pod formation stages increase the pod yield in groundnut.