Effects of 0.1 M ammonium sulfate, 0.1 M potassium phosphate, and 7 g/ha of the isopropylamine salt of imazapyr {(+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridinecarboxylic acid} were evaluated on the phytotoxicity of the ammonium salt of imazaquin {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid} and the ammonium salt of imazethapyr {(+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid} applied postemergence to pitted morningglory (Ipomoea lacunosa L. #3 IPOLA). While each of these salts and imazapyr applied alone had no effect, combining them with imazaquin or imazethapyr significantly increased control of pitted morningglory.
