Persistence of Cypermethrin and Fipronil in/on Chilli (Capsicum annuum Linn.)

Persistence of cypermethrin (Gold Cyp 10EC) @ 20 and 40 g ai ha−1 and fipronil (Regent 5 SC) @ 25 and 50 g ai ha−1 in/on chilli fruits following their spray application at the recommended and double the recommended doses is reported. Two foliar sprays of each insecticide were given at fortnightly interval beginning with the flowering/fruiting stage. The samples of chilli fruits drawn on 0, 1, 3,7,10, 15 and 20 days after the second spray revealed average initial deposit of cypermethrin at two respective doses as 0.230 and 0.537 μg g−1 which dissipitated to below detection limit (BDL) after 10 days of the second application. In case of fipronil the average initial deposit of 2.96 and 6.81 μg g−1 respectively dissipated to BDL and 0.001 μg g−1 on 20th day. No residues of cypermethrin and fipronil were detected in chilli fruits after 10 and 20 days respectively. Half-life of cypermethrin on fruits was in the range of 1.98–2.68 days and that of fipronil 1.71 -1.57 days.