Measurement of aminocarb in long-distance drift following aerial application to forests.

Abstract

A major concern associated with aerial forest spraying programs has been the extent of offtarget loss of insecticide due to vo la t i l i za t ion and aerial d r i f t (Ecobichon 1982). Early deposition studies with DDT revealed that only about 40% of the applied material reached the ground in cleared areas (Symons 1977). The aerial d r i f t of fenitrothion was reported as early as 197]; fenitrothion was detected at considerable distances from the si te of application (Yule et al. 1971). Poor deposition of aerially-applied fenii-~ot-~Tion was confirmed in deposition studies that detected levels of 0.8 ug cm -2 on collector plates when, in theory, at an application rate of 210 g ha -l , the concentration should have approached 2.1 ug cm -2 (Wood and Stewart 1976). Fenitrothion residues of the order of 0.02 0.15 g ha l have been measured in blueberry f ie lds at distances of 3 8 km downwind of sprayed forest tracts (Wood and Stewart 1976). More recent studies with a pesticide simulant revealed airborne concentrations of 6 16% of the amount applied at a distance of 7.5 km from the spray si te (Crabbe et al. 1980a).