Bioefficacy and residues of imidacloprid in chillies used against chilli thrips

摘要

Imidacloprid an insecticide belonging to chloronicotinyl group was applied as seed treatment, root dip and foliar spray for the management of thrips on chillies. Seed treatment of imidacloprid 70 WS at 10, 20 and 30g kg~(-1) protected the seedlings in the nursery upto 45 days. The root dip of the seedlings before transplanting had no effect on the thrips population. Foliar treatment of imidacloprid 200 SL at 250, 375 and 500 ml ha~(-1) reduced the thrips population significantly and also recorded higher yield of chilli fruits. There was no phytotoxicity in the chilli plants due to the treatment of imidacloprid either as seed treatment, root dip or foliar application. Residue analysis in the chilli fruits collected in the first harvest (7 weeks after last foliar application) revealed that the residue was at below detectable limit.