Study on Dissipation and Decontamination of Dichlorvos and Monocrotophos Residues in Grape Berries

A Study was carried out for dissipation and decontamination of dichlorvos (0.1%) and monocrotophos (0.05%) on Thompson Seedless grapes at experimental plot, Bolaram, Ranga Reddy District, Andhra Pradesh, India during October to March. Residue analysis by GLC revealed that the initial deposits of dichlorvos and monocrotophos recorded as 0.57 and 1.43 mg/kg, respectively dissipated to 0.03 (93.88%) and 0.25 (82.26%) mg/kg by 20^th day after eighteenth spraying. The half-life and waiting periods worked out to be 5.00 and 8.69 days, respectively for dichlorvos and 9.67 and 23.70 days, respectively for monocrotophos. Dipping of grape berries in one per cent acetic acid (vinegar) solution for 10 min followed by washing in plain water and dipping in two per cent salt solution for 10 min followed by plain water wash proved effective in removing dichlorvos and monocrotophos residues, respectively from grape berries.