Germination and Growth of Grasses and Legumes from Seeds Treated with Glyphosate and Paraquat

Abstract

In greenhouse studies, glyphosate [N-(phosphonomethyl)glycine] at 1.0 and 3.0 kg/ha and paraquat (1,1′-dimethyl-4,4-bipyridinium ion) at 0.6 kg/ha were applied to exposed seeds of six grasses and two legume species on continuously wet soil. Glyphosate reduced germination of both legumes and three grasses and reduced seedling growth of all species. Paraquat was toxic only to the grasses. Glyphosate mainly affected germination and growth of legumes when applied directly to their seeds. Reductions also were measured, however, when untreated legume seeds were transferred to glyphosate-treated soil.