Synergism with Imazamox Co-applications for Red Rice Control

A study was conducted at three locations in Louisiana to evaluate the interactions of imazamox at 44 g ai ha−1mixed with propanil, thiobencarb, or with a prepackaged mixture of propanil plus thiobencarb. A synergistic response was observed for red rice control for all treatments at 14 days after treatments (DAT); however, at 21 DAT a neutral response was observed for imazamox mixed with propanil or thiobencarb. A synergistic response occurred for red rice control when imazamox was mixed with propanil plus thiobencarb at 3360 g ai ha−1for all evaluation dates; however, imazamox mixed with propanil plus thiobencarb at 1680 g ha−1resulted in synergism at the same evaluations except at 35 DAT with neutral response. Synergism was observed for barnyardgrass control with imazamox mixed with propanil plus thiobencarb at 3360 g ha−1at 35 and 49 DAT. The only antagonism observed for barnyardgrass control was at 42 DAT with imazamox plus propanil at 840 and 1680 g ha−1or mixed with the prepackage mixture at 1680 g ha−1. Rice treated with imazamox mixed with propanil plus thiobencarb at 3360 g ha−1yielded 5770 kg ha−1.