INFLUENCE OF ADJUVANTS ON THE ANTAGONISM OF GRAMINICIDES BY BROADLEAFHERBICIDES

Field experiments evaluated barnyardgrass, broadleaf signalgrass, and rhizomatous johnsongrass control with sethoxydim, clethodim, fluazifop -P, quizalofop-P, and fenoxaprop applied alone and with bentazon or ch lorimuron when crop oil concentrate or BCH 815 was used. Bentazon stro ngly antagonized sethoxydim and clethodim. BCH 815 partially reduced t he antagonism with sethoxydim and clethodim compared with crop oil con centrate. Chlorimuron was most antagonistic towards fluazifop-P, fenox aprop, and quizalofop-P, and BCH 815 did not reduce antagonism. Additi onal experiments evaluated Italian ryegrass control with diclofop appl ied alone and with bromoxynil, metribuzin, 2,4-D amine, or tribenuron plus thifensulfuron with these adjuvants. The amine formulation of 2,4 -D and tribenuron plus thifensulfuron reduced Italian ryegrass control with diclofop, irrespective of the adjuvant.