Laserfiche WebLink
Page 12 of 23 <br />Appendix 1 <br />Management <br />Diffuse and spotted lrnapweed can be managed similarly. They are readily controlled with herbicides. <br />However, the weeds will reinvade unless cultural techniques aze used. <br />Chemical Control of Spotted Knapweed <br />Research conducted at Colorado State University indicates that Tordon 22K (picloram} at 1 to 2 pt/A, <br />Transline (clopyralid) at 0.67 to 1 pt/A, Curtail (cJopyralid + 2,4-D) at 4 to G pt/A, or <br />BanvelNanquish/Clarity (dicarnba) at 1 to 2 pt/A control diffuse knapweed. Tank mixes of <br />BanvelNanquish/Clarity plus 2,4-D at 1 pt + 2 pt/A or BanvelNanquish/Clarity plus Tordon 22K at 1 to 2 <br />pt + 0.5 to 1 pt/A or Tordon plus 2,4-D at 0.75 pt + 2 pt/A all control diffuse knapweed. These tank-mixes <br />may save money and reduce grass injury resulting from higher use rates of a single herbicide. <br />Spotted knapweed and diffuse knapweed generally occupy the same areas in Colorado, so the same <br />herbicide treatments can be applied, Weed scientists at Montana State University indicate that 1 pt/A of <br />Tordon (0.25 Ib) controls spotted knapweed for two to three years, but the weed will reinvade the area <br />unless other management techniques are used. <br />Mechanical Control of Spotted Knapweed <br />If desirable grass competition is evident in diffuse or spotted knapweed stands, judicious herbicide <br />application that does not injure grasses may allow them to compete effectively with the weeds. Irrigation <br />(where possible) may help stimulate grass competition in these cases. However, infested rangeland or <br />pastures often are degraded, allowing knapweed invasion, and herbicides alone will not restore the land to a <br />productive state. Seeding suitable perennial grasses is necessary to prevent weed reinvasion. <br />• <br /> <br />Diffuse knapweed <br />