Seasonal incidence of yellow stem borer, Scirpophaga incertulas (Walker) in Rice

Abstract

The seasonal incidence of rice stem borer was studied in rice cv. CO 51, a short duration, high yielding variety during August 2016 to May 2017. Maximum dead heart and white ear damage was recorded during first fortnight of November (13.41%) and second fortnight of March (10.41%), respectively. Monitoring of adult yellow stem borer through light trap catches recorded the prevalence of yellow stem borer throughout the study period with its peak activity on the second fortnight of December (189 nos). Similarly less number of unhatched eggs was found during the first fortnight of December (7.69%) and more number during the first fortnight of May (100%). Studies on correlation of abiotic factors with seasonal incidence of stem borer on the cv. CO 51 showed a negative correlation to relative humidity and rainfall. Significant negative correlation was observed for minimum relative humidity and wind speed with light trap catches. The influence of previous fortnight weather parameters with light trap catches showed a significant negative correlation with maximum temperature and wind speed. Rainfall of previous fortnight data showed a significant positive correlation with the adult moth activity.