Abstract
A supervised trial was undertaken at Tamil Nadu Agricultural University Orchard, Coimbatore, India, to test the dissipation pattern of quinalphos insecticide on mango (Mangifera indica L cv. Neelum) fruits during the summer of 1995. Quinalphos was sprayed at 15-day intervals at rates of 0.05% and 0.1% by volume on mango when the fruits were at marble size stage. The average initial deposit of the quinalphos residues in mango fruit samples after the second application of quinalphos at a rate of 0.05% was found to be 3.76 parts per million (ppm) which was reduced to 0.14 ppm, 15 days after spraying with 96% dissipation. At the higher dose (0.10%), the initial deposit was 6.75 ppm at 0 day which was reduced to 0.23 ppm after 15 days with 97% dissipation. Hence, a waiting period of 11.5 days and 14.2 days after treatment, is required for the safe consumption of fruits at the recommended and double the recommended doses, respectively, before harvest.
