Effect of age of rice plants on the development of sheath blight

摘要

Susceptibility to the sheath blight initially increased with the increasing age of rice plants and 45-day-old plants showed the maximum disease intensity. Thereafter, susceptibility decreased with the increase in age of plants. Early sowing minimizedthe disease development and gave higher yields. The maximum disease development occurred in the crop sown during 1 st July to 1 st August when average temperature, humidity and rainfall were 25.4-28.1°C, 77.4-82.3% and 6.9-15.1 cm, respectively. The disease intensity was negatively correlated (r = -9940) with the grain yield.