Response of Tomato (Lycopersicon esculentum) and Onion (Allium cepa) to Several Postemergence Grass Herbicides

Abstract

Sethoxydim {2-[1-(ethoxyimino)-butyl]-5-[2-ethylthio)propyl]-3-hydroxy-2-cyclohexene-1-one}, KK 80 {ethyl-4-[4-[4-(trifluoromethyl)phenoxy] phenoxy]-2-pentenoate}, and RO-13-8895 {acetone-0-2-[D-2-[δ,δ,δ-trifluoro-p-tolyl)-oxy] phenoxy] propionyl] oxime} did not injure plants visibly or reduce the yield of tomatoes (Lycopersicon esculentumL.). Diclofop LC [2,4-(2,4-dichlorophenoxy)phenoxy] propanoic acid] and diclofop HC in combination with oil or surfactant reduced tomato yield because tomatoes retained more of these spray solutions. No herbicide treatments injured onions (Allium cepaL.). All compounds controlled most grass weeds. Tomato plants grown at 29/18 C were injured more by some diclofop treatments than plants grown at 18/7 C. Cell membrane permeability of tomato plants treated with diclofop alone or in combination with adjuvants increased as visual injury symptoms became more severe.