Dissipation Dynamic of 20% Dichlorvos·Fenvalerate Emulsifiable Concentrate in Peach

The dissipation dynamic of 20%dichlorvos·fenvalerate EC in peach was studied,and the safe application standards were discussed.Results of field test showed that the half life of dichlorvos and fenvalerate in peach growing statges with 200 mg/L of dichlorvos·fenvalerate EC was 1.0～1.3 days or 4.1～4.6 days,respectively.The dichlorvos and fenvalerate residue was no detection～0.023 mg/kg or 0.010～0.066 mg/kg in 7 days or14 days before harvest.The peach were treated two and three times with two dosages of 100 mg/L and 200 mg/L.Therefore it is recommended that the pre-harvestinterval(PHI)of dichlorvos·fenvalerate EC of 100 mg/L in peach was no less than 7 days.Recommend value of MRL for dichlorvos and fenvalerate both were 0.2 mg/kg.