Pesticide Residue Laboratory Indian Institute of Horticultural Research, Hessaraghatta, Bangalore-560 089.
The persistence and dissipation of the residues of dimethoate and fenthion on mango fruits following their foliar spray applications for control of fruitfly and stone weevil infestations was studied. Dimethoate residues dissipated at the half life of 3.1 days to persist for 10 days and fenthion dissipated at the half life of 3.7 and 5.6 days to persist for 10 to 15 days respectively from their two application rates reflecting faster decay of dimethoate residues. Based on the peresistence pattern and prescribed MRL values for the two insecticides, the waiting periods of 0–1 days was worked out for their residues to reduce to safe limits.
