Submitted to: Western Society of Weed Science Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2000
Publication Date: 3/1/2001
Citation: BOYDSTON, R.A., HUTCHINSON, P.J., RANSOM, C.V., WELCH, L.L., KNABKE, J.J. WEED CONTROL WITH SULFENTRAZONE AND FLUMIOXAXIN IN PACIFIC NORTHWEST POTATO PRODUCTION. PROCEEDINGS OF WESTERN SOCIETY OF WEED SCIENCE, 54:3, #22. 2001. Interpretive Summary:
Technical Abstract: Sulfentrazone and flumioxazin were tested in Russet Burbank potatoes for crop tolerance and weed control at three locations in 2000 representing major potato growing regions in Idaho, Oregon, and Washington State. In all three trials herbicides were applied after the final hilling and prior to potato and weed emergence. Flumioxazin applied at rates ranging from 0.05 to 0.13 lb ai/a controlled hairy nightshade and common lambsquarters in late June from 85 to 91% and redroot pigweed from 63 to 80% in Idaho trials. Flumioxazin did not control tame oats. In Oregon, flumioxazin controlled redroot pigweed in early June from 56 to 85% and control increased as flumioxazin rate increased from 0.05 to 0.13 lb/a. Early season common lambsquarters and hairy nightshade control ranged from 75 to 100%. Flumioxazin failed to control barnyardgrass. In Washington, flumioxazin controlled redroot pigweed, common lambsquarters, and hairy nightshade for the entire season at rates from 0.05 to 0.13 lb/a. Flumioxazin failed to control large crabgrass, which was controlled well by a postemergence application of clethodim. In Idaho, sulfentrazone applied alone from 0.06 to 0.13 lb/a controlled common lambsquarters, redroot pigweed, and hairy nightshade greater than 95%. Tame oats were not controlled well by sulfentrazone. In Oregon trials, sulfentrazone applied alone from 0.09 to 0.25 lb/a controlled common lambsquarters, redroot pigweed, and hairy nightshade greater than 90%. Sulfentrazone controlled barnyardgrass greater than 90% at 0.188 and 0.25 lb/a. In Washington, sulfentrazone controlled hairy nightshade, and sparse populations of common lambsquarters, and redroot pigweed greater than 99% at rates ranging from 0.09 to 0.25 lb/a but failed to control large crabgrass.