Effect of different leaf wetness durations and temperatures on incubation period and development of leaf blast disease of basmati rice

Effect of duration of leaf wetness on incubation period and development of rice leaf blast revealed that a minimum of 12 hours of leaf wetness was required for infection and symptoms appeared within 7 days of incubation period. The incubation period decreased while disease severity increased significantly with increase in leaf wetness from 12 to 48 hours. A positive correlation between leaf wetness duration and disease severity was observed. Maximum increase in lesion length was recorded at 25°C followed by 20°C. Increase in lesion length was minimum at 10°C.