Epidemiology of Cercospora Leaf Spot of Black Gram

Leaf spot of black gram caused by Cercospora canescens Ell. and Mart. is an important disease of black gram in Tamil Nadu. Studies were undertaken on the role of abiotic factors in disease development, and to find out suitable dates of plaptlng to avoid losses due to leaf spot disease in black gram. First two sowings during June suffered low disease incidence. Higher temperatures are correlated with low disease index while higher RH and rainfall are associated with high disease Index. Greater Inoculum load during the later part of the year also plays a major role in disease development.