BENTAZON TANK-MIXTURES FOR IMPROVED REDROOT PIGWEED (AMARANTHUS-RETROFLEXUS) AND COMMON LAMBSQUARTERS (CHENOPODIUM-ALBUM) CONTROL IN NAVY BEAN (PHASEOLUS-VULGARIS)

Field studies were conducted from 1991 to 1994 to investigate the effe ctiveness of reduced rates of bentazon in tank-mixtures with imazethap yr, thifensulfuron, or HOE 075032 for improved control of redroot pigw eed and common lambsquarters in navy bean. Tank-mixtures of bentazon a t 600 g ai/ha plus imazethapyr at 25 g/ha or HOE 075032 at 5 to 15 g/h a controlled both redroot pigweed and common lambsquarters. These rate s represent an approximate 45% reduction in total amount of active ing redient needed to control these weeds compared with full label rates. Bentazon tank-mixtures with 2 or 4 g/ha of thifensulfuron controlled t hese weeds but caused severe injury and delayed crop maturity. In gree nhouse studies, the GR(25) for HOE 075032 in navy bean was > 90 g/ha, while in soybean it was 16 to 24 g/ha.