Dissipation of Endosulfan and Lindane on Sunflower Seeds and Cowpea Pods

Persistence of endosulfan and lindane in emulsifiable concentrate formulations was investigated on sunflower and cowpea at the recommended (T₁) and double the recommended (T₂), doses. The total residues of endosulfan (Endosulfan A + Endosulfan B) 2.370 μg g⁻¹ in T₁ and 3.030 μg g⁻¹ in T₂, exceeded MRL value of 2 ppm in sunflower seeds at harvest. The corresponding lindane residues of 0.197 ug g”¹ in T, and 0.680 jig g”¹ in T₂ were also above the MRL value. On cowpea pods, residues of endosulfan in T₁ and T₂ and lindane in T₁ were below their respective MRL values at one DAT. Endosulfan dissipated by about 46–92% and lindane by 26–89% by harvest. Washing and cooking of cowpea pods reduced endosulfan residue by 37–90% and 78–96% respectively. The loss of lindane residues on cooking was 87–90%. A waiting period of 3 d has been suggested for these insecticides on cowpea.