|FELIX, JOEL - Oregon State University|
Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2010
Publication Date: 10/3/2010
Citation: Felix, J., Boydston, R.A. 2010. Evaluation of Imazosulfuron for Yellow Nutsedge (Cyperus esculentus) and Broadleaf Weed Control in Potato. Weed Technology. 24:4 471-477.
Interpretive Summary: Yellow nutsedge is a difficult to manage perennial weed and present in many potato production areas of the Pacific Northwest. Yellow nutsedge reduces potato tuber yield and quality and when not controlled and greatly reduces yield of rotational crops and land values. Partial control of yellow nutsedge has primarily been accomplished through the use of soil-active herbicides, which are applied before the weed emerges. These studies determined the most effective rates and timings of a new herbicide, imazosulfuron, for yellow nutsedge and broadleaf control in potato, Imazosulfuron slightly injured potato soon after application and potato grew normally and produced high yield and quality of tubers thereafter. Imazosulfuron controlled yellow nutsedge equal to or better than currently registered herbicides in potato. Imazosulfuron appears to be safe for use on potato and a promising tool for yellow nutsedge management in potato-based cropping systems.
Technical Abstract: Field studies were conducted in 2007 and 2008 near Nyssa, OR, Pasco, and Paterson, WA to evaluate yellow nutsedge and broadleaf weed control and potato tolerance to imazosulfuron. No injury symptoms from imazosulfuron were evident on potato at Nyssa whereas in Washington studies, imazosulfuron caused some chlorosis of potato foliage ranging from 6 to 15% and <4% at 6 and 15 days after POST application, respectively. Sequential applications of imazosulfuron controlled yellow nutsedge better than a single PRE application. Sequential applications of imazosulfuron or imazosulfuron in combination with s-metolachlor controlled yellow nutsedge 92 and 89% at 21 and 42 days after POST applications, respectively. Imazosulfuron controlled 98% of common lambsquarters and 100% of pigweed species. Imazosulfuron provided season long control of common mallow at Nyssa. However, imazosulfuron failed to control Russian thistle at Paterson, and only partially controlled hairy nightshade. Yield of U. S. no. 1 potato at Nyssa ranged from 44.4 to 54.2 T/ha and 42.1 to 52 T/ha for imazosulfuron PRE and imazosulfuron sequential treatments in 2007 and 2008, respectively. U. S. no. 1 potato yield following imazosulfuron PRE and sequential treatments at Pasco ranged from 48.5 to 57.4 T/ha in 2007, and at Paterson from 35.8 to 54.3 T/ha in 2008. Lower yields in 2008 were attributed to poor control of hairy nightshade. Imazosulfuron has potential to become a valuable tool for yellow nutsedge management in potato. Studies are needed to evaluate the soil persistence for imazosulfuron in order to determine safety to crops grown in rotation with potato.