The protection of carrots against carrot fly psila rosae with granular and emulsifiable concentrate formulations of chlorfenvinphos incorporated in gels used for drilling pre germinated seed in a sandy loam
Thompson, A.R.; Suett, D.L.; Percivall, A.L.
Annals of Applied Biology 101(2): 229-238
Field experiments were done in a sandy loam in 1979 and 1980 to investigate the performance against carrot fly on carrots of e.c. [emulsifiable concentrate] and granular formulations of chlorfenvinphos incorporated in gels used for drilling pre-germinated seed. With 9.4-66.7 mg a.i.[active ingredient]/m row, the 2 formulations performed similarly in a natural hydrocolloid and a mineral colloid gel. The emergence of carrot seedlings 6-7 wk after drilling was similar on plots with untreated gel and those with insecticide-treated gel and, .apprx. 6 mo. after drilling when > 90% of carrots grown without insecticide were damaged by carrot fly larvae, an .apprx. 6-fold increase in dose of both formulations increased the estimated larval mortality from about 70 to 95%. Mean concentrations of residues of total (Z + E) isomers of chlorfenvinphos in harvested carrots treated with 9.4-56.5 mg a.i./m row were less than the proposed FAO/WHO tolerance for chlorfenvinphos (0.4 mg/kg). The initial rates of release of available chlorfenvinphos from a granular formulation immersed in the 2 types of gel differed markedly but, after 48-h immersion, > 50% of the insecticide was released into both gels.