Everything you need to know about greengram cultivation, harvest and growth. Learn about:- 1. Introduction to Greengram 2. Geographic Distribution of Greengram 3. Climate Required for Cultivation 4. Soil Required for Cultivation 5. Field Preparation 6. Sowing Time 7. Manures and Fertilizers Required for Cultivation 8. Water Management 9. Weed Management 10. Cropping Systems and Few Others.
- Introduction to Greengram
- Geographic Distribution of Greengram
- Climate Required for Cultivating Greengram
- Soil Required for Cultivating Greengram
- Field Preparation of Greengram
- Sowing Time of Greengram
- Manures and Fertilizers Required for Greengram Cultivation
- Water Management of Greengram
- Weed Management of Greengram
- Cropping Systems of Greengram
- Harvesting and Threshing of Greengram
- Yields and Storage of Greengram
1. Introduction to Greengram:
Greengram is popularly known as mungbean or golden gram is one of the most important short duration pulse crops grown in India. The seeds are highly nutritious as it contains about 23.86% protein, 62.6% carbohydrates, 1.15% fat, 5.27% crude fibre, 3.32% ash besides rich in lysine (436 mg/g).
It is also rich in Ca, Fe, K and is a good source of vitamins such as thamin, niacin and vitamin A. Mungbean seeds are sprouted for fresh use or canned for shipment to restaurants. Sprouts are high in protein (21-28%), calcium, phosphorus and certain vitamins, besides they also synthesize ascorbic acid (vitamin C).
Qualitatively, mungbean has higher digestibility coefficient (79 %) and biological value. Unlike other pulses, it does not produce heaviness or flatulence. The whole or split grains are used as a daI or made into flour. The straw and husk are used as fodder for cattle. Grains are also used in many Indian dishes.
Being a legume, it has the capacity to fix the atmospheric nitrogen (30-50 kg/ha). After picking of pods, green gram plants may be used as green manure. It also helps in preventing soil erosion because of its spreading growth habit. Greengram provides quality green fodder to the cattle.
After harvesting the pods, green plants are uprooted or cut from ground level and chopped into small pieces and fed to the cattle. The straw and husks are also used as fodder for animals. Seed coat, cotyledons and broken parts of embryo, after soaking in water, can be used as high quality cattle feed.
With the availability of short duration and photo-insensitive varieties, it has become possible to cultivate mungbean as a catch crop as well as a summer crop. Its cultivation is highly beneficial in areas where turn around period is about 60-70 days, viz., rice-wheat cropping sequence of N-W India, where field remain vacant for about 60-70 days and 90- 100 days after the harvest of wheat in April and potato, mustard and sugarcane in March, respectively. This period may be well utilized by summer cultivation of mungbean in irrigated areas.
Greengram is believed to be a native of India and central Asia as Vigna radiata var. sublobata found in wild state in India and Indonesia is the closest relative of blackgram and believed to be the progenitor of greengram. From India it spread to China, Japan, Iran, and Africa etc.
Greengram belongs to the Legume family of plants and are closely related to cowpea (in the same genus but different species). They are warm season annuals, highly branched and having trifoliate leaves like the other legumes. Both upright and vine types of growth habit occurs in mungbean, while plants varying from 45-120 cm in length with slight tendency of twining. It possesses highly proliferated deep root system with maximum root mass found in the first 30 cm depth.
The stems are ridged and succulent having 6-9 branches on them. The central stem is more or less erect, while side branches are semi-erect. The leaves are alternate, trifoliate, and dark-green with scattered hairs on both sides on a long petiole. Both the stems and leaves are covered with short hair, generally shorter than those of blackgram.
The flowers are pale yellow in colour, appear in axillary raceme in clusters of 10-25 in number. They are self-pollinated and develop into 6-10 cm long hairy pods, which are variable in colour (yellowish brown to black) and contain 10-15 oblong seeds in them.
The seeds are small and nearly globular. Mature seed colours can be yellow, brown, mottled black or green, depending upon variety- The hilum is white, more or less flat. The 100-seed weight varies from 1.56 to 4.0 g depending on the variety. Germination of greengram is epigeal with the cotyledons and stem emerging from the seedbed.
2. Geographic Distribution of Greengram:
Greengram is an important crop of India and south East Asia. It is widely cultivated in India, Sri Lanka, Pakistan, Bangladesh, Thailand, Cambodia, Vietnam, Malaysia, China, Fiji, Australia, America and Africa.
India is the major producer of green gram in the world and has about 31.088 thousand ha area and produces about 9.463 thousand tonnes with an average productivity of 304 kg/ha during 2005-06. Major green gram growing states are Maharashtra, Rajasthan, Andhra Pradesh, Uttar Pradesh, Orissa, Madhya Pradesh, Bihar and Karnataka.
3. Climate Required for Cultivating Greengram:
Greengram can be grown from sea level to an altitude of 2,000 metre. Due to the availability of both short-day and long-day varieties, greengram can be grown successfully in almost all the season. In southern parts of India, it can be grown throughout the year as the variation in temperature is not much. Generally it is cultivated in winter season in peninsular India and is mostly grown during kharif, spring and summer seasons in north-India.
Other than kharif seasons, irrigation is necessary for its cultivation. Adequate rainfall is required from flowering to late pod fill in order to ensure good yield. It is grown in the areas receiving a well distributed annual rainfall of 50-75 cm. Rains during flowering are detrimental as they affect pollination and fertilization. The crop is drought resistant but frost, waterlogging and salinity is very harmful to greengram. It can tolerate higher temperature up to 40°C but does well in temperature range of 30-35°C is the optimum.
A hot humid climate with sufficient soil moisture is ideally suited for better growth and development of the crop. It is a short day plant and required 12-13 hours of photoperiod for flowering and increase in photoperiod above this range delays reproductive phase. Warmth environment and bright sunshine are beneficial for flowering. High humidity and excess rainfall late in the season can result in disease problems and harvesting losses due to delayed maturity.
4. Soil Required for Cultivating Greengram:
Greengram do best on fertile sandy, loam soils with good internal drainage. However, it can be raised on a wide array of soils ranging from red laterite soils of south India to heavy black cotton soils of Madhya Pradesh, and sandy soils of Rajasthan. In general, deep, well- drained loam soils of the alluvial tracts are ideal for mungbean cultivation.
The crop can be grown on shallow eroded soils and is considered as a good cover crop. Acidic, saline and waterlogged soils are not suitable for its cultivation. Performance is best on soils with a pH range between 6.2-7.2 and plants can chow severe iron chlorosis symptoms and certain micronutrient deficiencies on more alkaline soils.
5. Field Preparation of Greengram:
Tillage operation to prepare seed-bed for greengram depends on the soil type, cropping system and season of planting. The soil should be tilled to remove weeds and to prepare a seed-bed which will provide good seed-soil contact. The final seed-bed needs to firm with a surface free of clods and debris to allow a good distribution of seeds. Normally, the crop does not require a fine seed-bed.
Depending upon the soil type and preceding crop, 2-3 ploughings or harrowings followed by planking are adequate. It is essential to have a weed-free seed-bed with adequate provision for quick drainage during kharif. For spring and summer mungbean, a pre-sowing irrigation is needed soon after harvesting of rabi crop. When soil attains proper tilth, the land should be prepared with cross harrowing. Land levelling is required for uniform distribution of irrigation water.
When crop is sown in post-monsoon season on residual moisture conditions, care should be taken to conserve moisture by way of minimum cultivation just to make a proper seeding condition at uniform depth. In other words, if moisture is short, keep pre-plant tillage to minimum to prevent drying the top 5-7.5 cm soil layer. When the crop is sown as intercrop, the tillage requirement of the main crop decides the field operation. In kharif rice fallows (utera system), it is raised without tillage.
6. Sowing Time of Greengram:
In kharif, greengram sowing depends on onset of monsoon, preferably be sown in between the first week of June to mid-July. In any case, sowing should not be done beyond July end. In Rabi sowing should be done from September to October or January, depending upon the time of rice harvest and availability of irrigation. In the states of Orissa, Andhra Pradesh, greengram is sown in standing crop of rice, 7-10 days before harvest.
Spring mungbean is sown in the month of February after harvest of early rabi crops of potato, and toria in north India. Similarly after harvest of rabi crops of wheat, rapeseed and mustard etc. in the months of March-April, summer mungbean is sown. In any case, summer sowings should not be delayed beyond April, because reproductive phase will coincide with rains leading to prolonged vegetative growth and delayed maturity.
Cultivation of greengram during summer has several advantages viz. it is less prone to the attack of insect-pests and diseases, besides improving the fertility status of the soil through biological N fixation, control weeds and check wind erosion. Being a short duration crop, it suits well in various cropping rotation, thus cropping intensity can be increased by growing of summer mungbean.
It improves the physico-chemical and biological properties of the soil. Moreover, mungbean acts as a multipurpose crop, because after picking of pods, the foliage can be incorporated into the soil as green manure in order to boost the soil fertility and reduce the N requirement of succeeding crops.
Only certified seed should be used so that quality and variety purity are guaranteed. During kharif season, greengram makes luxuriant vegetative growth with lateral spreading of branches and hence requires wider spacing than other seasons. In kharif, and rabi seasons, mungbean is sown in rows 30-45 cm apart. The plants are thinned to a distance of 5.0-7.5 cm.
Thus the optimum population varies from 3-7 lakh/ha that would require a seed rate of 20-25 kg/ha. In other seasons (spring or summer), the crop is sown in rows 25-30 cm apart with an intra- row spacing of 5 cm. The optimum population thus varies from 6-8 lakh/ha and would require 30-35 kg seed/ha. Broadcast sown crop in rice fallows requires still higher seed rate.
Treat the seeds with carbendazim or thiram @ 2 g/kg of seed 24 hours before sowing (or) with talc formulation of Trichoderma viride @ 4g/kg of seed (or) Pseudomonas fluorescens @ 10 g/kg seed. Bio control agents are compatible with bio-fertilizers. First treat the seeds with bio-control agents and then with Rhizobium. Fungicides and bio-control agents are incompatible.
Treat the seeds with 3 packets (600 g/ha) of Rhizobial culture and 3 packets (600 g/ha) of Phosphobacteria. If the seed treatment is not carried out apply 10 packets of Rhizobium (2000 g/ha) and 10 packets (2000 g) of Phosphobacteria with 25 kg of FYM and 25 kg of soil before sowing.
The seeds are sown in furrows opened by plough or line sown using seed drill. Careful adjustment in seed-drills must be made to properly deliver and distribute the small seeds of mungbean. Seeds should be planted 2-5-3.5 cm deep in a well prepared seedbed with good moisture content.
If the surface layers are dry this depth can be increased to 6-7 cm if the soil type is one which does not crust easily. The seedlings of mungbean can have a hard time breaking through a thick crust and stands will be reduced.
In utera cropping, seeds are broadcast in standing rice crop from flowering to 2-3 days before its harvest.
7. Manures and Fertilizers Required for Greengram Cultivation:
Greengram is generally raised on the residual fertility of soil. If available, 8-10 tonnes of FYM or compost should be applied 15 days before sowing. If organic manure is not available, fertilizer application is necessary. On an average 10 quintals of greengram removes about 40 kg N, 4-5 kg P, 10-12 kg K, 1-1.5 kg Ca, 1.5 to 2 kg each of S and Mg per ha. Therefore, these nutrients must be supplied through organic or inorganic sources.
Mungbeans require phosphorus, potassium and certain micronutrients at levels similar to other pulse crops. The amount to add as fertilizer should be based on soil test levels, organic matter content and projected yield level. Long duration varieties and the crop grown under irrigated conditions respond to higher doses of fertilizer. Mungbean fixes atmospheric nitrogen in association with Rhizobium. If the field has been previously inoculated with the proper Rhizobium for nitrogen fixation, additional nitrogen is not required.
However, the N fixation starts from 2nd week after sowing with its peak at 40-50 DAS. To meet the initial requirement of N before start of N fixation, 15-20 kg N/ha is applied along with 40-60 kg P2O5/ha as basal at the time of last ploughing.
For the growth and development of root nodules, phosphorus application is essential. In general, 100 kg di-ammonium phosphate (DAP)/ha would meet the nutrient needs of the crop. Use of PSB culture with phosphatic fertilizer improves the yield and available phosphorus status in the soil. Foliar sprays of 2% DAP at flowering and pod filling stages is promising.
The response of crop to K fertilization is rare. However, in deficient soils, soil test based K fertilization is necessary. If soil pH is below 6.3, lime should be added to raise pH to the desired level. For best results, lime should be applied one year prior to growing mungbeans and thoroughly incorporated. In saline soils and intensive cropping systems, crop responds to Zn and S fertilization.
Application of 20 kg each of zinc sulphate and sulphur is recommended for higher yields. P fertilization through single super phosphate would take care of S needs of the crop. Zinc fertilization is needed once in 3 years. In addition to these fertilizers application of 0.5 kg manganese, 1 kg copper, 0.6 kg boron, 0.1 kg molybdenum and 1 kg iron enhance the yield of mungbean considerably.
8. Water Management of Greengram:
Mungbean is predominantly grown as a rainfed crop during kharif season and requires irrigation only when monsoon rain fails or long dry spell is observed at flowering or grain development stage. Water requirement of green gram is 15-30 cm. One to two irrigations (5- 7 cm water per irrigation) at flowering and pod formation stages are required to boost the yield. In rice fallows, under utera cropping, the crop faces severe moisture stress at reproductive stage. Thus irrigation at flowering or early podding is highly beneficial.
During other seasons, the crop is grown under irrigated conditions. Besides a pre-sowing irrigation, 3-4 irrigations at 15-20 days interval are optimum for summer mungbean and water should be applied at 50 % soil water depletion from its maximum root zone depth.
In summer season (grown after wheat), no irrigation should be given after 40-45 days of sowing. Waterlogging should be avoided at flowering and pod filling stages, especially during rainy season as it may cause drastic reduction in yield.
9. Weed Management of Greengram:
Initial 30-40 days after sowing is critical period of crop-weed competition. During this period, crop should be kept with minimum competition from weeds. Due to continuous rains in kharif and broadcast sowing in utera cropping, mungbean suffers from intense weed competition than other seasons.
The major weed flora of greengram includes Trianthema monogyna; Portulaca oleracea, Eargrostis riparia, Cyperus rotundus, Cynodon dactylon, Dactyloctenium aegipticum, Echinochloa colonum; Digitaria sanguinalis, etc. Rotary hoeing and/or field cultivation should be used as required to remove weed competition until flowering begins. Later emerging weeds are not as damaging to yield as the early ones.
Avoid cultivation in the field when the plants are still damp because this can spread bacterial and fungal disease. Farmers planting mungbean for the first time should plan on using wider row spacings so that cultivation can be done if weeds become a problem.
The crop requires 2 hand weedings, first at 20-25 days after sowing (DAS) and the later at 40-45 DAS. In summer, one weeding is sufficient. During kharif season, use of herbicides is ideal, as utility of manual weeding is limited by continuous rains.
Pre-plant incorporation of fluchloralin (Basalin 45 EC) @ 0.70 kg/ha or Trifluralin (Treflan 48 EC) @ 0.96 kg/ha or pre-emergence application of pendimethalin (Stomp 30 EC) @ 0.75 kg/ha has been found effective in control of weeds.
Application of pendimethalin (Stomp 30 EC) @ 0.45 kg/ha as pre-emergence integrated with one hand weeding gives best results. Post-emergence herbicides like fluazifop @ 0.5 kg/ha or haloxyfop-methyl @ 0.24 kg/ha 20 DAS for grasses have proved effective in weed management in utera cropping, where hand weedings are not possible.
10. Cropping Systems of Greengram:
Green gram is mainly grown as rainfed crop during kharif. It is also grown as rabi crop after rice in Maharashtra, Andhra Pradesh and Tamil Nadu. Presently, summer cultivation is gaining popularity in northern India to utilize the available period in between the harvest of rabi crop and sowing of kharif crop. Short duration varieties of green gram matures in 60-70 DAS and can be well fitted between rabi and kharif cereal crops. Greengram is grown as relay cropping, intercropping and mixed cropping.
Greengram is a promising inter or mixed crop for kharif as well as long duration crops. Greengram is grown mixed with sorghum, pearl millet, maize, pigeonpea and cotton during kharif season. Intercropping of greengram can also be done with spring planted sugarcane. In this way, an additional grain yield of 0.5-0.6 tonnes/ha may be obtained without any adverse effect on the performance of sugarcane.
Sugarcane is planted at a distance of 90 cm from row to row. Two rows of greengram 30 cm apart in the center of sugarcane rows leaving 30 cm distance between sugarcane and greengram rows are sown with a seed rate of 7-8 kg/ha. Pigeonpea intercropped with greengram in 1:1 ratio resulted in higher yields. In Rajasthan, Pearl millet + greengram is a promising cropping system.
Mungbean matures in 80-85 days in kharif and 65-70 days in spring season. Pod maturity in mungbean is not uniform because the plants flower over an extended period. This makes it difficult to decide when to harvest. Generally harvest should begin when one half to two-thirds of the pods are mature. Seeds might be between 13%-15% moisture at this time. It is harvested when more than 80% pods mature. Shattering of pods is a great problem with this crop.
Harvesting at physiological stage is beneficial and this stage is recognized by uniform shedding of leaves and brown colour of pods with hard seed. If the variety does not have synchronous maturity, pods have to be harvested manually as and when they mature. Two to three rounds of picking of pods are recommended to avoid losses due to shattering.
Varieties with synchronous maturity require one or two pickings and may even be harvested with sickles. The plants are cut with sickle and dried on the threshing floor. The green crop after picking may be fed to the cattle or may be incorporated into the soil. After harvesting, the produce is threshed by beating with sticks or by treading with bullocks. Finally seeds are winnowed to separate the chaff.
12. Yields and Storage of Greengram:
The yields of greengram depends largely on weather conditions, soil, cultural practices and variety. A good crop of greengram during kharif season may yields about 12-15 q grains/ha, while summer greengram may yields 15-20 q grain/ha and nearly equal quantity of straw (bhusa). Prior to storing, proper cleaning of seeds is essential to remove all leaf material, stems, immature pods, dirt, insect parts and other debris.
Mungbeans at about 12% moisture can then be stored in regular grain bins previously fumigated to control stored pests, if grains are higher in moisture then 12% they can be dried in sun until they are near the 12% value. Because they will be sprouted and eaten direct, care should be taken to keep all possible contaminants away from the storage area.
Milling of greengram involves removal of outer husk and splitting the grain into two halves. Milling may be done either by traditional method or by alternate drying and wetting method. After proper de-husking and splitting, polishing of split pulses is done by treating them with a small quantity of oil and or water.
Yield of split pulses in traditional mills is only 65-70 % in comparison to 82-85 % potential yield. Almost 80 % of the greengram is consumed in the form of dal. The seed coat accounts for about 15 % of seed weight and the remaining 85 % is cotyledons. The average yield of dal from greengram is 72 % of raw material.