Incidence of Cotton Thrips (Thrips tabaci Lindeman) and Its Correlation with Weather Parameters

Investigations on incidence of cotton thrips (Thrips tabaci Lindeman) on Bt and non-Bt cotton hybrid were carried out at Main Cotton Research Station, Navsari Agricultural University, Surat (Gujarat) during Kharif, 2017-18. The thrips incidence initiated from fourth week of June and it continued till first week of December in Bt and non-Bt cotton. The peak activity of thrips was observed during third week of August in Bt hybrid and the higher fluctuation of thrips was observed during the second week of August to third week of September and first week of October. Thrips population had significant negative correlation with maximum temperature in Bt cotton. In case of non-Bt, the peak activity of thrips was found during first week of September. As far as association with abiotic factors was concerned, maximum temperature and bright sunshine hours had significantly negatively correlation, while minimum temperature and morning relative humidity were positively associated.