Submitted to: Western Society of Weed Science Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/1/2000
Publication Date: 3/1/2001
Citation: TONKS, D.J., HUTCHINSON, P.J., RANSOM, C.V., BOYDSTON, R.A., ROSS, C.G. PACIFIC NORTHWEST POTATO TOLERANCE AND VARIETAL RESPONSE TO SULFENTRAZONE. PROCEEDINGS OF WESTERN SOCIETY OF WEED SCIENCE. 54:43, #59. 2001.
Technical Abstract: Field studies were conducted in Idaho and Oregon, in 1999 and 2000 to evaluate potato tolerance to sulfentrazone. In Oregon the soil was a Oyhee silt-loam with pH 8.0 and 1.1% o.m. and in Idaho a Declo silt-loam with pH 7.9 and 1.2% o.m. Herbicides were applied after hilling and prior to potato emergence. Sulfentrazone was applied alone at 0.7 to 0.42 kg/ha, and at 0.11 or 0.21 kg/ha in mixtures with 0.56 kg/ha metribuzin, 3.4 kg/ha EPTC, 1.1 kg/ha s-metolachor, 0.72 kg/ha BAS 656 07H, or 1.1 kg/ha pendimethalin, depending on location. In Oregon, initial injury from sulfentrazone applied alone ranged from 0 to 8%. Initial injury in the Idaho trials ranged from 4 to 18%, depending on rate. Initial injury for mixtures ranged from 0 to 3% and 3 to 15% in Oregon and Idaho, respectively. In Oregon, U.S. No. 1 tuber yield was significantly reduced by 0.42 kg/ha sulfentrazone, while total tuber yield was not reduced by sulfentrazone treatments regardless of rate or mixture. Tuber yield was not affected by sulfentrazone in Idaho regardless of rate or mixture. Sulfentrazone tank-mixed with metribuzin or pendimethalin in Washington trials caused early visual potato injury, but potato tuber yield was not affected. In a separate 2000 Idaho trial, potato cultivar tolerance was evaluated. Sulfentrazone was applied PRE at 0, 0.11, and 0.21 kg/ha to 'Russet Burbank', 'Ranger Russet', 'Russet Norkotah', and 'Shepody' potatoes. Initial injury ranged from 5 to 25% and 'Russet Burbank' exhibited greatest visual injury during the season, compared to the other cultivars. Both U.S. No. 1 and total tuber yields were reduced in sulfentrazone-treated 'Russet Burbanks' relative to the untreated "Russet Burbank' control. Tuber yield was not affected in the other potato cultivars. Tuber yield was not affected in the other potato cultivars.