Persistence of O,O-diethyl S- (2-chloro-1-phthalimidoethyl) -phosphorodithioate (Torak) on and in lemons, oranges, and dried citrus pulp cattle feed, and toxicity of the residues to mites
Westlake, W.E.; Düsch, M.E.; Gunther, F.A.; Jeppson, L.R.
Journal of Agricultural and Food Chemistry 19(6): 1191-1195
Residues of dialifor (Torak) were determined on and in Valencia oranges, Eureka lemons and citrus pulp cattle feed prepared from treated oranges in California. The residue half-lives were 40-60 days on oranges and 60-80 days on lemons. Concentrate spray applications gave higher initial deposits and somewhat longer residue half-lives than did full-volume sprays. The difference in deposit may be due in part, at least, to the sampling technique used. There was a rapid penetration of the insecticide into the rind, but none into the peeled fruit. Washing was ineffective in removing dialifor residues. There was no evidence of the presence of the oxygen analogue, a potential metabolite. Evaluations were made with the citrus red mite [Panonychus citri] (M.G.) at each sampling interval to establish the effect of the type of application and kind of fruit on toxicity to mites. Low-volume applications were effective longer than the dilute applications and the residues were effective for a longer period on oranges than on lemons.