In laboratory incubation studies with 32 farm soils, the initial half-
life of freshly-applied phorate ranged from less than 1 to more than 1
6 weeks. Accelerated degradation was stimulated by a single applicatio
n of the recommended dose and occurred most readily at pH levels > 7.4
. It is recommended that the degradative properties of soils are estab
lished before insecticide treatments are selected. (C) 1997 Elsevier S
cience Ltd.