Persistence of Fenpyroximate in Chilli Pepper (Capsicum annum L.) and Soil and Effect of Processing on Reduction of Residues

摘要

Dissipation of fenpyroximate residues in fresh and dry chilli fruits and in red loam soil are reported following field application at single and double doses of 15 and 30 g ai ha~(-1). The residues were estimated using LC-MS/MS. The initial deposit of the acaricide on the fruit was 0.42 μg g~(-1) at single dose and 0.85 μg g~(-1) at the double dose, which dissipated below detectable level of 0.01 μg g~(-1) after 10 and 15 days, respectively. The half-life of fenpyroximate at the two doses was 2.12 and 3.13 days respectively. Processing factor due to sun drying in dry chilli fruits ranged from 2.51 to 3.33 during 0 to 10~(th) day after application. Different decontamination techniques reduced the residues on chilli fruits harvested 2 h after spraying by 21.83-65.89 per cent and 4.13-45.45 per cent on fruits plucked three days after application.