Submitted to: Extension Service Bulletins
Publication Type: Other
Publication Acceptance Date: 12/1/2004
Publication Date: 1/1/2005
Citation: Hutchinson, P.J., Boydston, R.A., Ransom, C. 2005. Weed management in potatoes with spartan herbicide. Pacific Northwest Extension Bulletin. 577:6.
Technical Abstract: Spartan (sulfentrazone) is a new herbicide for weed management in potatoes. Sulfentrazone applied preemergence controls hairy and black nightshade, redroot pigweed, common lambsquarters, and kochia in potatoes. Spartan may be tank mixed with metribuzin, s-metolachlor, rimsulfuron, pendimethalin, or EPTC to control grass weeds and broaden the spectrum of broadleaf weeds controlled. Sulfentrazone has a different mode of action from other potato herbicides making it a valuable tool for herbicide-resistant weed management. Sulfentrazone may be applied in center pivot irrigation systems, by ground driven sprayers, and by aircraft. All major potato varieties grown in the PNW exhibited tolerance to sulfentrazone. Some foliar injury was observed occasionally consisting of slight plant height reduction, transient black discoloration on foliage, and/or chlorosis on foliage. Minor injury observed did not relate to loss in tuber yield or tuber quality. Reduced plant vigor or heat stress combined with herbicide injury may result in reduced potato tuber quality and yield. Sulfentrazone can be more mobile in coarse, low organic matter soils with pH above 7.0. Sulfentrazone is degraded in the soil primarily by microbial activity. Drought or cooler than normal conditions may extend the half-life of sulfentrazone in soils. Plant back guidelines to rotation crops range from none for tolerant crops, such as mint to 18 and 24 months for sweet corn and canola, respectively.