Dissipation of endosulfan and dichlorvos residues in/on cauliflower curds

Dissipation behaviour of endosulfan and dichlorvos in/on cauliflower, variety Snowball-16, was studied during rabi season (Sep.-March) 2003-2004. Endosulfan and dichlorvos were sprayed @ 350 and 110g a.i. with 115 g a.i., respectively, 80 days after transplanting. Samples were taken at the interval of 0 (1h after spray), 3, 5, 7, and 10 days after spray (DAS) in triplicate and residues were estimated on GC-ECD system equipped with capillary column. The initial deposits of 3.452 and 0.295microg g(-1) of endosulfan and dichlorvos dissipated to 0.084 (97.56%) and 0.009 (96.95%), respectively after 10 DAS. Residues of endosulfan reached below maximum residue limit of 2microg g(-1) one day after spray and of dichlorvos were below MRL value of 0.5microg g(-1) even on 0 day. Dissipation pattern followed first order kinetics for both the insecticides with half life periods of 1.81 and 2.08 days for endosulfan and dichlorvos, respectively.