Compatibility of Diclofop and BAS 9052 with Bentazon

BAS 9052 {2-[1-(ethoxyimino)-butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} effectively controlled annual grasses in soybean [ Glycine max (L.) Merr.] alone or in combination with bentazon [3-isopropyl-1 H -2,1,3-benzothiadiazin-4(3 H )-one 2,2-dioxide] in greenhouse and field experiments. The activity of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} on annual grasses was reduced if combined with bentazon in a tank mixture. The wettable powder formulation of bentazon, as well as a day temperature of 30 C, slightly reduced the antagonistic interaction from that of the emulsifiable concentrate formulation of bentazon or a day temperature of 15 C. In greenhouse studies ‘Corsoy’ soybean plants were injured by the diclofop-bentazon combination. In field studies, however, the injury was not sufficient to reduce grain yields.