Residues of Cypermethrin and Fenvalerate on Brinjal

Single application of two synthetic pyrethroids viz., cypermethrin at 22.5, 45 and 75 g a.i. ha¹ and fenvalerate at 30, 60 and 112.5 g a.i. ha⁻¹ and endosulfan at 525 g a.i. ha⁻¹ were applied on brinjal and the residues were determined in terminal shoots at different time intervals and fruits at harvest. The initial deposits of cypermethrin at 22.5, 45 and 75 g a.i. ha⁻¹ were 0.31, 0.58 and 0.93 μg g⁻¹ and fenvalerate at 30, 60 and 112.5 g a.i. ha⁻¹ were 0.43, 0.55 and 0.94 μg g¹, respectively as compared to 1.25 μg g⁻¹, for endosulfan. The half- life values calculated were 3.30, 3.39 and 3.16 d for 22.5, 45 and 75 g a.i. ha⁻¹ cypermethrin, 2.98, 3.26 and 3.76 d for 30, 60 and 112.5 g a.i. ha⁻¹ fenvalerate and 5.29 d for endosulfan at 525 g a.i. ha⁻¹. The residue levels were found to be below MRL at 7 d for the pesticides under study.