Field studies were conducted to determine if POST applications of the p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors mesotrione (105 g ai/ha), topramezone (18 g ai/ha), and tembotrione (92 g ai/ha) applied alone and in mixtures with the photosystem-II (PSII) inhibitors atrazine (560 g ai/ha), bentazon (560 g ai/ha), or bromoxynil (280 g ai/ha) would control volunteer potato. Mesotrione alone controlled potato 62%, but topramezone and tembotrione only provided 10 to 22% control by 6 wk after treatment (WAT). All PSII inhibitors applied alone provided less than 36% control of potato. Overall, mixtures of PSII inhibitors plus mesotrione improved initial potato control by 2 WAT; however, by 6 WAT, few differences were observed between mesotrione applied alone or in mixtures with PSII inhibitors. PSII inhibitors did not always improve activity of topramezone or tembotrione on potato, and in some instances appeared to antagonize control. HPPD inhibitors applied alone or in combinations with PSII inhibitors reduced potato yields in comparison to the untreated check.
