Distribution and persistence of aerially sprayed permethrin in some terrestrial components of a boreal plantation forest

Abstract

An aqueous emulsion of permethrin was applied aerially at a dosage rate of 70 g of active ingredient (ai)/ha over a mixed boreal plantation forest near Sault Ste. Marie, ON, Canada. The initial residues after spray in soil and litter were low, 0.025 and 0.033 μg/g, respectively, and dissipated to levels below 0.005 μg/g within 6 days in soil and 16 days in litter. Initial residues (micrograms per gram) in foliage of four tree species were ca. 100 times higher than those in soil and litter. The broad leaves of aspen showed, on average, slightly higher residues than the conifer needles, probably due to a higher surface area-to-mass ratio