Dept. of Entomology, A.P. Agricultural University, Hyderabad-500 030, Andhra Pradesh.
1 Directorate of Rice Research, Rajendranagar, Hyderabad-500 030, A.P.
During 1980, when quinalphos at 0.075 per cent was sprayed twice on rainted ground-nut crop the initial deposit was estimated as 4.5 and 4.3 ppm for the two sprays by microbioassay while by chemical assay the levels were 4.3 and 4.2 ppm respectively. In 1980–81 (irrigated conditions), when quinalphos sprayed at three concentrations the initial deposit as per microbioassay was 5.4, 6.0 and 9.3 ppm and 5.5, 6.4, 11.3 ppm for first and second sprays respectively and by chemical assay it was 5.0, 5.7, 9.0 and 5.2,5.9 11.0 ppm for the respective sprays and spray concentrations. The residues were below tolerance limit by 15 days after spraying in both the seasons. The half life values during 1980 (unirrigated) was 3.7 and 5.5 days and during 1980–81 (irrigated) they were ranging between 4.5–5.7 days. The groundnut dried plants, kernel and oil did not record any detectable residues during both the seasons.
