Critical stage analysis for Alternaria leaf spot diseases against black gram under artificial inoculations

The present investigation was carried out to evaluate the critical stage for Alternaria leaf spot against black gram under artificial inoculation in pot culture. The study revealed that the susceptibility of the black gram plants to Alternaria leaf spot increased with the increase in age and it reached to maximum at the age of 40 DAS with PDI 57.60. Minimum disease was observed in the plants ageing 10 DAS with PDI 16.80. In general, as black gram plants grew older, they became more susceptible to A. alternata. The study showed no severe infection of Alternaria leaf spot in younger leaves and plants of black gram.