Effect of weather factors on seasonal incidence of major sucking insect pests on Bt and non-Bt cotton under rainfed conditions of Odisha

Abstract

A field experiment was carried out to study the effect of weather factors on seasonal incidence of major sucking insect pests on Bt and non-Bt hybrid (Bunny) cotton during Kharif, 2013 and 2014 at Regional Research and Technology Transfer Station farm at Bhawanipatna, Kalahandi, Odisha. The incidence of sucking pests was observed from 1st week of August (32nd SMW) and continued up to last week of December (52nd SMW). The population of aphids (42.16 and 59.32/ 3 leaves) at 37th and 36th SMW; jassids (15.62 and 16.40/ 3 leaves) at 40th and 41st SMW; thrips (2.32 and 2.82/ 3 leaves) at 41st SMW and 35th SMW; whiteflies (5.72 and 5.40/ 3 leaves) at 41st and 41st SMW; and red cotton bug (7.78 and 7.96/ plant) at 48th and 48th SMW attended the peak in the year 2013 and 2014 respectively. No significant difference was observed with respect to the population of any of the sucking pests on Bt and non-Bt cotton. The population buildup of aphids, jassids and thrips were positively correlated with the mean minimum, mean maximum and mean average temperature, morning, evening and mean relative humidity and rainfall while whiteflies positively correlated with mean minimum, mean maximum and mean average temperature and rainfall. Red cotton bug showed negatively non-significant correlation with all the weather parameters.