Rhizoctonia Aerial Blight of Soybean, its Prevalence and Epidemiology: A Review

Soybean [Glycine max (L.) Merrill] is high value oilseed crop grown throughout the world as well as in few soybean growing pockets in India. The hot and humid weather conditions during the soybean cropping season favours the attack by various fungal, bacterial and viral diseases, thereby lowering the crop productivity. Rhizoctonia aerial blight or web blight disease, caused by Rhizoctonia solani is considered one of the most economically important disease of soybean in India. It causes yields losses ranging from 3560% which might reach a devastating level of 80% under favourable environmental conditions. In India, the disease has been reported from most of the soybean growing states of Uttrakhand, Rajasthan, Sikkim, Haryana, Punjab, Uttar Pradesh, Bihar, Madhya Pradesh, Chhattisgarh and Assam. Epidemiological studies prove to be very important in managing the disease as the disease severity highly depends on the weather variables prevailing in the growing season. The present review has attempted to compile findings on this devastating disease of soybean crops, its prevalence in the country, epidemiological studies and strategies on integrated disease management.