Prediction of damage and yield loss caused by rice leaffolder at different crop periods in a susceptible rice cultivar (IR 50)

Abstract

Abstract: The predicted damage and yield loss under field conditions caused by rice leaffolder (Cnaphalocrocis medinalis) Guenee to the rice cultivar IR 50 was more in the unprotected crop than in protected crop. The yield loss was more when the infestation occurred at 40 days after sowing (DAS) than at 30, 60 and 80 DAS. The damage and yield loss was not concomitant with the larval population. The economics of protection of grain crop showed that the protection was not necessary when the crop was infested at 30, 60 and 80 DAS while at 40 DAS the protection was necessary. A seed crop may warrant protection of the crop at both 30 and 40 DAS.