Effect of weather parameters on the seasonal incidence of rice leaf folder (Cnaphalocrosis medinalis, Gunee)

Abstract

Study was undertaken to determine the effect of weather parameters on rice leaf folder during 2015-16 at Krishi Vigyan Kendra Jagatsinghpur, Odisha. The leaf folder infestation was monitored through light trap catches and the infestation percentage was observed during crop period and correlated with weather parameters. Results indicated that the peak activity of rice leaf folder was in the third week of September with 25.39 per cent leaf infestation. It was associated with 30.71 0C to 22.79 0C maximum and minimum temperatures and 92.00 and 45.00 per cent morning and evening relative humidity with the association of 65.8 mm rainfall. The correlation study revealed that the number of rice Leaffolder infestation were significantly correlated with maximum temperature (r= 0.465) and minimum temperature (r=0.381). Increasing temperature within upper threshold of the species promoted leaf folder growth. and showed negative and non significant correlation with average rainfall (r = - 0. 15), morning relative humidity (r = - 0.14) and evening relative humidity (r = - 0. 12).