Dissipation of Cypermethrin Residue on Chickpea

Dissipation of cypermethrin residue on chickpea was studied following its application at the rate of 60 and 90 g a.i. ha⁻¹ twice, first at pod initiation stage of the crop and second 15d after the first application. The initial deposits of cypermethrin on green pods were 0.42 and d.60 mg kg⁻¹ at low and high doses respectively. These dissipated with half-lives of 8.4 and 9.4 d to the extent of 73.81 and 70.00% respectively in 15 days. The safe waiting periods were found to be 25.8 and 33.8 d for the two treatments. At harvest, residue of cypermethrin in chickpea dry pod covers and straw were 0.05 and 0.06 mg kg⁻¹ at low and 0.09 and 0.09 mg kg⁻¹ at the high dose respectively. However, residue of cypermethrin in chickpea grains were 0.02 and 0.03 mg kg⁻¹ at low and high doses, respectively and were well below MRL. Washing of chickpea pods with water removed 32.0 to 45.0% and cooking 44.0 to 60.0% of the residue.