Field studies were conducted in 1999 and 2000 at seven locations in south Texas to evaluate flufenacet plus isoxaflutole for weed control and corn tolerance. Palmer amaranth control with flufenacent plus isoxaflutole was variable, with no greater than 60% control at one location and greater than 95% control at another. The poor control at the one location was probably due to lack of rainfall for 3 to 4 wk after corn was planted. Flufenacet plus isoxaflutole at 0.56 or 0.7 kg/ha controlled Texas panicum at least 80%, whereas flufenacet plus isoxaflutole rates lower than 0.56 kg/ha provided variable control (55 to 99%). Flufenacet plus isoxaflutole at 0.35 and 0.49 kg/ha controlled pitted morningglory at least 83%. Corn stunting (3 to 16%) with flufenacet plus isoxaflutole was noted at the one location where the soil sand content was greater than 80% and moisture was received within 48 h of herbicide application. With few exceptions, corn weed control and yield with flufenacet plus isoxaflutole combinations were generally comparable to those observed for the atrazine and acetochlor standard treatments.
Nomenclature: Flufenacet; isoxaflutole; Palmer amaranth, Amaranthus palmeri S. Wats. #3 AMAPA; pitted morningglory, Ipomoea lacunosa (L.) # IPOLA; Texas panicum, Panicum texanum Buckl. # PANTE; corn, Zea mays L., ‘AS986’, ‘DK668’, ‘Pioneer 3223’, ‘Pioneer 32K61’.
Additional index words: Corn tolerance, weed management.