Persistence of Quinalphos and Monocrotophos on Cotton Plant and their Effect on Pink Bollworm Incidence

Residues of quinalphos and monocrotophos were assayed in different cotton plant parts (var. H 565). The residues of quiualphos fell below detectable limit on 16th day of application and monocrotophos persisted upto 24 days. The trend of persistent was same for both the insecticides i.e. highest amount was present in leaves and bollrind followed by flowers, squares and seed cotton. No amount could be detected from all the treatments in seeds. Incidence of, pink bellworm on squires and flowers was found significantly less in all the treatments as compared to the control. On green bolls also, the infestation was found significantly less. Although both the insecticides controlled this pest effectively but monocrotophos proved better in controlling pink bollworm.