1Deptt. of Entomology, HPKV, Palampur, 176062, (H.P.).
Studies on persistence and effect of processing on monocrotophos residues in potato tubers were carried out at Palampur, District Kangra (H.P.) during 1990. The residues were estimated on 10, 20 and 30 days after foliar spray of monocrotophos by bioassay and chemical assay. Monocrotophos residues persisted above the tolerance level of 0.05 ppm on 20th day after application at both the dosages i.e. 0.5 and 1.0 kg a.i./ha both in processed and unprocessed potato tubers. Whereas on 30th day the residues were below the detectable limit even in unprocessed tubers at both the doses. The half life values obtained with recommended and double the recommended doses were 5.82 days and 5.97 days, respectively. At least 30 days safety interval should be required with both the doses for the consumption of potato tubers without any appreciable risk.
