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Page 10 of ?3 <br />Russian knapweed <br />?'-- f <br />r I 1 <br />Awe, <br />Management <br />Appendi\ I <br />Like other creeping perennials, the key to Russian knapwced control is to stress the weed and cause it to <br />expend nutrient stores in its rout system. An integrated management plan should he developed that places <br />continual stress on the weed. Currently, the best management plan includes cultural control combined with <br />mechanical ;And or chemical control techniques. A single control strategy, such as mowing or a herbicide, <br />usually is not sufficient. <br />Russian knapwced typically invades degraded arras, dominating the plant community and desirable plants <br />(e.g. perennial grasses). Seeding competitive, perennial grass species (cultural control) after Russian <br />knapwecd has been stressed by other control measures (,set-up treatments) is essential. Set-up treatments <br />may include chemical or mechanical methods. <br />Cooperative research between Colorado State University and the University of Wb .oming showed that <br />chemical set-up treatments were superior to mowing. Curtail (clopyralid + 2,4-U), Escort (mctsulfuron), <br />and Roundup (glyphosatc) were used to suppress Russian knapwced. Then perennial grasses were sown in <br />late tall as a dormant seeding. Tillage is necessarv to overcome the residual allclopathic effects of Russian <br />knapwced. Curtail 0 quarts per acre) (A) or Escort ( I ounce A) were applied at the bud-growth stage. <br />Roundup was applied twice at I quart. A, first at the bud-growth stage and again about K weeks later. <br />Curtail controlled Russian knapwced hest, but Roundup failed to control it. <br />None of the herbicides in seeded grasses. Grasses established similarly among herbicide suppression <br />treatments, even though Russian knapwced control varied. I iowever, where Escort or Roundup ways used to <br />suppress Russian knapwecd, additional herbicide treatments would be necessary to achieve acceptable <br />control. <br />While two mowings, eight weeks apart (first at bud-growth stage), suppressed Russian knapwecd during <br />that year, the weed recovered vigorously the subsequent season. perennial grasses established in the <br />mowing treatments but much less than in herbicide treatments. Two mmkings per year for several years <br />may control RuNsian knapwecd better, but further research is needed to test this hypothesis. Currently, no <br />biological conirtil is available for this weed.