Dissipation and decontamination of acephate residues in grapes

A study was conducted on Thompson Seedless grape on dissipation of acephate applied @ 0.75 kg a.i/ha (2 g L⁻¹). It was sprayed at weekly intervals starting from day 3 to 122 days after pruning (October). The initial deposits of 4.61 and 1.40 mg/kg of acephate and methamidophos (toxic metabolite of acephate) on grape berries, were detected, respectively. The half-life of acephate and methamidophos worked out to be 3.01 and 2.60 days, respectively and waiting periods for harvesting the grape berries were 5.13 and 10.04 days. Dipping of grape berries in 2% salt solution for 30 min followed by washing facilitated the removal of acephate residues to an extent of 72.74 and 45.36 % correspondingly at 1 and 5 days after spraying.