Among the varieties mentioned,'T 9' is early-maturing (75-80 days), dwarf,photo-insensitive and suitable for planting in all the seasons-spring summer and rainy seasons,throughout the country. It also fits well in different multiple-cropping systems.'Pusa sel 1' is high-yielding,medium in maturity (85-90 days) and fairly resistant to viral diseases.

Seeding technique
Seeding @ 15 to 25 kg/ha in rows 30 cm apart is optimum.A spacing of 5-10 cm between plants is recommended.

Application of fertilizers
A starter dose of 10 to 15 kg nitrogen and 25 to 40 kg P2O5 per hectare is adequate for blackgram. Application of 70 to 80 kg diammonium phosphate (DAP) per hectare is most convenient,as it meets adequately the total requirement of nitrogen and phosphorus. Molybdenum also helps in increasing crop production.
Weed control
When sown as a sole crop,1 or 2 weedings are needed in the initial stages to keep the field free from weeds. However,1 weeding 30-40 days after sowing is found to be enough. The pre-emergence application of Lasso @ 1.5kg ai/ha keeps the field from weeds for the first 50 days and thereafter the crop smothers the weeds.

Irrigation
Blackgram is grown purely as a rainfed crop during kharif and on residual moisture in rice fallows during rabi. In case there is a long dry spell, the crop is benefited if 1 irrigation is given. Similarly,during the winter season,if irrigation facilities are available,1 light irrigation at podding/seed-filling stage is beneficial to the crop. Excess water at any stage affects the crop adversely.

Insect pests
1.Red hairy-caterpillar (Amsacta moorei Butl.). It is a serious pest of kharif crop including blackgram in India.The adult insect is a nocturnal moth with white wings. During day-time the moths remain on the leaves which can be collected and immersed in kerosinised water to destroy them. Deep ploughing of wastelands and infested areas,and use of light traps reduce the insect population. Dusting with BHC 10% @ 25 kg/ha or spraying of 0.07% Endosulfan or 0.05% Parathion minimizes the losses.

2.Bihar hairy-caterpillar [Spilosoma obliqua (Walker)]. This is a polyphagus insect and attacks a number of crops,including greengram and blackgram. The young caterpillars feed on the leaf tisues having chlorophyll and skeletonise the leaf. The larva is black and hairy,and orange at both ends.Deep ploughing immediately after the harvest will expose the pupae and kill them.Dusting of BHC 10% @ 25 kg/ha or spraying of 0.07% Endosulfan or 0.05% Quinalphos would kill the larvae.

3.Jassids (Empoasca kerri Pruthi). Jassids are serious pests of greengram,blackgram and cowpea.They suck the juice from the mesophyll of the leaves and as a result the leaves turn brown and leaf surface becomes uneven.In case of severe infection,the leaves dry up and fall and weaken the plant.Application of Disulfoton 5G or Aldicarb 10G @ 2 kg/ha,or spraying 1.0 kg each of BHC and DDT in 500 litres of water per hactare in the beginning of August and again at the end of August controls jassids. Spraying of 0.04% Monocrotophos emulsion or 0.1% Lindane emulsion is also effective.

4.White-fly (Bemisia tabaci G.). The white-fly is a tiny, soft-bodied insect with white wings and yellow body. It causes serious damage by sucking the plant sap. Besides, it acts as a vector for yellow-mosiac virus and as such is more dnagerous than the virus it transmits. The white-fly can be controlled by a number of chemicals including systemic insectisides, like Disulfoton, Phorate or Aldicarb, which keep the crop safe for 4-6 weeks. Later, 2 or 3 sprays of 0.1% Malathion + 12% orchard oil will keep the crop safe from the pest.

5.Galerucid beetle (Madurasia obscurella Jacoby). The beetle stipples the leaves, particularly of the young plants. As a result the crop growth is retarded. The insects are more active during the cooler parts of the day, and during the night. During the hot day-time, they remain hidden in cracks on the ground or loose soil. The grubs remain in the soil near the plants and feed on the root hairs. Spraying 0.07% Endosulfan or dusting with 5% BHC controls foliage damage.

Diseases
1.Cercospora leaf-spot. The casual organism is Cercospora canescens Ellis & Mart. The disease is characterized by the production of lesions which turn brown with reddish-brown margins. Similiar spots also occur on pods. The pathogen survives on plant debris. If the infection starts early in the season, it causes heavy reduction in the yield. Spraying with Captan or Zineb @ 2 g/litre or Bavistin @ 0.5 kg in 1,000 litres of water per hectare controls the disease incidence. Blackgram variety '4-5-2' is reported to be resistant to leaf-spot.

2.Powdery-mildew (Erysiphe polygoni DC.). The disease is characterized by the production of white, powdery growth on the leaves. In case of severe infection, defoliation occurs and pods fail to develop. Sulphur dusting @ 25 kg/ha or spraying of wettable sulphur @ 3 kg/ha, 2 to 5 times during the crop season helps to check the disease. Spraying with Karathane (1 ml per litre of water), or with Bavistin (0.5 g per litre of water) twice at 15-day interval is also effective in controlling the disease.

3.Yellow-mosiac.The symptoms appear on young leaves as mild scattered yellw specks.Yellow areas go on increasing in the new growth and ultimately some of the apical leaves turn completely yellow.The diseased plants usually mature later and bear relatively few flowers and pods. The pods are stunted and mostly remain immature but whenever seeds are formed they are small.The infected leaves turn necrotic.If the infection takes place early in the season,the plants die without producing any seed. The disease is transmitted by the white fly.With a view to controlling the incidence of white fly,0.07% Endosulfan or 0.05% Malathion or 0.03% Methyl Demeton + 2% orchad oil may be sprayed.The resistant varieties, like 'Pusa 1','Mash 1-1','Mash 48','UPU 1','UPU 2','4-5-2','UG 117' and 'Pant U 26',need to be popularized.

4.Leaf-crinkle. This disease has been recorded only on blackgram The symptoms are enlargement of leaf size followed by crinkling of lamina.Young leaves show pronounced incidence. No control measures have yet been evolved. Use of disease-free seed is recommended.

5.Leaf-curl. The earliest symptoms appear on young leaves in the form of chlorosis around veins near the margin. Affected leaves become brittle and fall down with the slightest jerk. Plants generally remain stunted and majority of them die due to top-necrosis withina week or two. The use of healthy seed and resistant varieties, like 'T 27','BR 68','No. 55','Sindkheda',N 212' and 'Khargone 3, are recommended.

6.Bean-mosiac. The first symptoms appear on the young leaves in the form of irregular chlorotic areas that expand rapidly. These are soon followed by mosiac, vein-banding, puckering and distortion of leaves. In severe cases, the leaf is stunted and bleached. The seeds get shrivelled and the of seeds per pod is decreased. The disease is seed-borne, hence only certified disease-free seed should be used. Early roguing of diseased plants will appreciably reduce the infection and increase yield. Resistant blackgram varieties, like 'D 6-7','Gwalior 18','Khargone 3' and 'N 212', need to be popularized and used in breeding programmes.