Current Status and Prospect of Web Blight of Cowpea: A Review

Pulses in India have been considered as the poor man's only source of protein. Among them cowpea (Vigna unguiculata) is an important food legume which is also known as vegetable meat due to high amount of protein in the grain with better biological value on dry weight basis. Various factors viz., diseases and insect pests are mostly responsible for its low production. Among diseases, web blight caused by Rhizoctonia solani is one of the most important disease of cowpea. The web blight appears every year at varying intensity and causes heavy losses in yield. Web blight disease is most severe at seedling and vegetative stage. The disease is characterized by oval or spindle shaped brown black lesions having length ranging from 0.2–8 cm at soil level near collar region and girdling the basal portion of the stem and lesions developed by basidiospores of Thanatephorus cucumeris which are 2–4 mm in diameter, circular and appear as brown necrotic spots with light brown centre. Cob web like symptoms also noticed hence, the name web blight.