Synergistic Interactions of Tebuthiuron with EPTC + R-25788 and Butylate + R-25788 in Corn (Zea mays)

Abstract

Preplant-incorporated applications of commercial formulations of EPTC (S-ethyl dipropylthiocarbamate) and butylate (S-ethyl diisobutylthiocarbamate) plus the herbicide antidote R-25788 (N,N-diallyl-2,2-dichloroacetamide) were evaluated for their interactions with preemergence applications of tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} in corn (Zea maysL., ‘Pioneer 3780’) under greenhouse conditions. The thiocarbamate herbicides plus the antidote were used at 1.1, 2.2, 3.4, and 4.5 kg/ha, and they were evaluated against 0.3, 0.6, and 1.1 kg/ha of tebuthiuron. Shoot dry weight and shoot height of corn seedlings were measured at 24 days after treatment. Growth responses of corn to combination treatments of these herbicides were significantly reduced. Statistical analysis of the data showed that tebuthiuron interacted synergistically with both EPTC and butylate in the presence of the herbicide-antidote R-25788.