Interaction of Selected Insecticide-Herbicide Combinations on Soybeans (Glycine max)

Abstract

Phorate {O,O-diethylS-[(ethylthio)methyl] phosphorodithioate}, disulfoton {O,O-diethylS-[2-(ethylthio)ethyl] phosphorodithioate}, linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], or metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] when used alone did not reduce soybean [Glycine max(L.) Merr. ‘Calland’] grain yield or plant population. However, combinations of metribuzin with either phorate or disulfoton interacted synergistically to reduce both soybean grain yield and plant population significantly even at recommended rates of both chemicals. Combinations of linuron with either phorate or disulfoton at recommended rates did not reduce soybean grain yield or plant population. Greenhouse studies further substantiated the synergistic interaction of phorate or disulfoton with metribuzin.