Zineb (0.2%) and Copper oxychloride spray are two fungicides, which help in curtailing of the disease by spraying at regular interval of 15 days. A combination of Zineb with Streptocycline can also be used.
Powdery Mildew: this disease generally affects leaves covering with mycelia patches with fruiting bodies. Due to this many plants die prematurely after defoliation. Warm temperature of 33%, high humidity of 80% and bright sunshine are congenial conditions for this disease. This disease can be controlled by application of Benlate and Sulphur compounds. Powdery Mildew can be controlled by treating seeds with streptocycline (0.025%) and also spraying with combination of Streptocycline and Dinocap (both 0.01%).
Dry root rot: caused by Macrophomina phaseolina. It may occur as seedling blight on the growing cotyledons as elongated black cankers at any stage of growth. In mature plants the disease occurs as bronzing of leaf, followed by drooping of the upper tender part of the shoots. Occurrence of this disease may decrease nodule formation. This disease can be controlled by rotation with less susceptible crops like moth bean or pearl millet. Zinc or Copper (5kg/ha) or Sulphur ( 20kg/ha) is used for prevention. Bavistin seed treatment (2g/kg of seed) is also highly effective in preventing this disease.
Bacterial Leaf Blight: this disease is cause due to scattered rain, high temperature of 20 to 30oC and humidity. Plants infected at very early stage may die due to rotting of the stem. Oxidase enzymes like polyphenol oxidase and per-oxidase enzyme may help in this disease resistance.
Apart from these there are some other additional treatments for curtailing diseases:-
- The seeds can be treated with hot water at 65oC for 10 minutes before sowing.
- Spraying Streptocycline @150ppm twice at 15 days of interval.
- To check the presence of pest, fungi and bacteria during storage, Kitazin 2mg/kg of seeds with Chloropyriphos 4ml/kg and Streptocycline 1g/kg seed can be used.
- In the month of May, soil solarisation also help in disease prevention.