POSTEMERGENCE DIRECTED APPLICATION OF BENTAZON PLUS METRIBUZIN FOR BROADLEAF WEED-CONTROL IN RUSSET BURBANK POTATOES

Field studies were conducted to evaluate potato (cv. Russet Burbank) i njury and weed control with mid- or late-postemergence directed applic ations of bentazon at 0.56, 0.84, or 1.12 kg ha(-1) + metribuzin at 0. 28 kg ha(-1) + petroleum oil concentrate (POC) at 2.3 L ha(-1). Potato injury was 5% or less when bentazon + metribuzin + POC was applied as a postemergence directed spray. Hairy nightshade, redroot pigweed, an d common lambsquarters control were excellent with all rates of the be ntazon + metribuzin + POC mixture tested at either application time. I n weed-free trials, neither U.S. No. 1 nor total tuber yield was reduc ed compared to the untreated control by any rate of the bentazon + met ribuzin + POC mixture applied as a directed spray. Thus, postemergence directed applications of bentazon + metribuzin + POC show excellent p otential for broadleaf weed control in Russet Burbank potatoes.