Corynespora Leaf Spot of Blackgram (Vigna mungo (L.) WileaeK)

Abstract

A new leaf spot disease of black gram was found at Chainat Field Crops Research Center on hybird lines limported from India, Pakistan and the Philippines. The symptomns on the leaf were reddish brown, circular or irregularly shaped zonate sports. The morphology of the causal agent was studied in detail and identified as the fungus Corynespora cassiicola (Berk, & Curt.) Wei, Artificial inoculation was conducted on 4 lines of one month old black gram hybrids, namely lines 280/20013 (India), 293/24001 (Afghanistan), 266/14001 (Philippines) and 265 (Kolodal). All plants were obviously infected 2 days after inoculation. Symoptoms on line 293/24001 Afghanistan were more severe than the others.