Fate of Acephate in the Cotton Plant1

Studies using 14C acephate and thin-layer chromatography (TLC) showed that foliarly applied acephate is rapidly absorbed into cotton leaf tissue, with nearly 40% of the applied acephate present in the leaf tissue at 24 h post treatment. Successive foliar applications at 5-day intervals indicated that minute amounts of acephate are trans located into the fruiting form. Although the amount of acephate in the fruiting form increased after three successive foliar applications, the concentration of acephate probably would not be high enough to be insect toxic. Foliar applications of acephate followed by analyses of the entire cotton plant for acephate and its primary metabolite, methamidophos (O, S-dimethyl phosphoramidothioate), by using gas chromatography, indicated that acephate has a half-life of 8 days in the cotton plant.