Effects of seven herbicides and two herbicide formulations on the phytotoxicity of glyphosate {[N-(phosphonomethyl)glycine]} were studied in the greenhouse. All herbicide formulations tested reduced glyphosate toxicity; the degree of reduction among herbicides varied. Type of formulation did not alter the reducing effects of propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine] or propachlor (2-chloro-N-isopropylacetanilide). Liquid formulations of cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl] amino]-2-methylpropionitrile} and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] caused less reduction than the wettable powder formulations, but the liquid formulation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] caused greater reduction than the wettable powder. Inert ingredients of the herbicide formulations were primarily responsible for reduced glyphosate toxicity.
