Bioefficacy and residues of spinosad and emamectin benzoate on brinjal

In the present study, bioefficacy of spinosad (56.25, 72 and 90 g a.i. ha-1) and emamectin benzoate (5, 6.25 and 12.5 g a.i.ha-1) was studied in comparison to cypermethrin (50 g a.i. ha-1) and self-formulated neem seed extract (5 %). Field experiments were undertaken for two cropping seasons during kharif 2005 and summer 2006. From the study it was found that spinosad afforded moderate control of jassid, whitefly and aphid. However, it was found to be the most effective against BSFB. Although corresponding yield recorded in cypermethrin (check treatment) was higher (16.30 and 21.01 t ha-1) it was not significantly different than that noticed in spinosad and emamectin benzoate. Residues of spinosad and emamectin benzoate were studied by the validated analytical method using high performance liquid chromatograph with UV detector. Based on the dissipation of residues on fruit after last spray of spinosad (90 and 180 g a.i. ha-1) and emamectin benzoate (12.5 and 25.0 g a.i. ha-1), initial residues reached below detection limit (TBDL) in about 14 to 16 and 2 to 6 days, respectively.