Abstract

Dissipation of chlorpyriphos 20 EC was studied in/on curry leaf (Murraya koenigii). Two rounds of sprays were given at 10 days interval using knapsack sprayer at the rate of 2 ml l-1 of water. Leaf samples were collected at different days (0, 1,3,5,7,10,15,20, 30and 35 days) until it reached below detection level (BDL). Recoveries of chlorpyriphos 20EC were 102, 118 and 108% from the samples fortified at 0.05, 0.25, and 0.5 µg g-1,respectively. Initial deposits were found to be 12.60 µg g-1and 26.14 µg g-1 in recommended and double the recommended dose. More than 80% of initial deposit was dissipated within three days both in recommended and double the recommended dose and reached BDL by 30thand 35thday, respectively. Half life of chlorpyriphos 20EC residues were 4.15 and 4.4 days in recommended and double the recommended dose, respectively.

Keywords: Curryleaf, Chlorpyriphos 20EC, Residues, QuECHERS method