Dissipation of Dichlorvas and Dimethoate Residue in Okra

An experiment was laid out in a randomized block design, replicated thrice using okra var., “Arka Anamika” to study the dissipation pattern of dichlorvos and dimethoate EC's @ 0.2% and 0.06%, respectively. The crop was sprayed five times at an interval of 10 d initiating 30 d after sowing. The residue estimation was done by GC-ECD for dichlorvos and GC-NPD for dimethoate. The initial deposits of 2.07 and 2.93 mg kg⁻¹ of dichlorvos and dimethoate, dissipated to 0.04 mg kg ⁻¹ (98.97%) and 0.31 mg kg⁻¹ (89.42%), respectively, in 10 d after five sprayings. The waiting periods (T₁₀₁) for dichlorvos and dimethoate were worked out to be 2.34 and 2.19 d, respectively.