Influence of weather parameters on the occurrence of major insect-pests in conventional rice ecosystem

摘要

To assess the impact of weather parameters on rice pests, a field experiment was conducted in rice ecosystem during 2013-2014 at Agricultural Research Station, Gangavathi, Koppal district of Karnataka. The rice insect-pests infestation was monitored through light trap catches during 52 standard weeks of the study period and correlated with weather parameters. Results indicated high pest incidence during the months of October (Rabi, 2014). The favourable weather conditions for high incidence of rice leaf folder, leaf and plant hoppers were 38.80"C mean temperature with a corresponding relative humidity that ranged between 85.30 to 92.80per cent during the rabi season. The correlation studies made between BPH, WBPH and weather parameters revealed a positive relationship with morning relative humidity (r = 0.04 and r = 0.19) and evening relative humidity (r = 0.09 and r = 0.17), respectively. Whereas, high incidence of yellow stem borer (YSB) was observed in the second fortnight of April with a 37.43°C and 52.71 per cent mean temperature and relative humidity, respectively. Maximum temperature had a positive effect on male (r= 0.31) andfemale (r= 0.24) moth of the yellow stem borer population.