Abstract:
The persistence of dichlorvos, carbaryl, pirimicarb and cypermethrin insecticides was studied on the alfalfa crop. Dichlorvos, carbaryl and cypermethrin, each at 0.2% and pirimicarb at 0.1% concentration were applied to the leaves of the crop. Samples for residue analysis were collected at 0, 1, 2, 4, 8, 10, 14 and 17 days post-treatment. The samples were extracted for residues and analysed on gas liquid chromatograph. The degree of persistence, in terms of residual life, amongst the insecticides tested was on cypermethrin > carbaryl > pirimicarb > dichlorvos. Residues of carbaryl subsided well below the tolerance limit (100 ppm) one day after application while that of dichlorvos reached the tolerance limit (0.5 ppm) 2 days after application to the alfalfa crop.
Page(s):
132-135
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Scientific and Industrial Research, Volume: 30, Issue: 2, Year: 1987