Laserfiche WebLink
Page 13 of 23 <br />Management <br />Appendix I <br />Diffuse and spotted knapweed can be managed similarly. They are readily controlled with herbicides. <br />However, the weeds will reinvade unless cultural techniques are used. <br />Chemical Control of Diffused knapweed <br />Research conducted at Colorado State University indicates that Tordon 22K (picloram) at 1 to 2 pUA, <br />•fransline (clopyralid) at U.67 to 1 pUA, Curtail (clopyralid + 2,4-D) at 4 to 6 pU.A, or <br />Barrel/Vanyuish/C'larity (dicamba) at I to 2 pUA control diffuse knapweed. "Tank mixes of <br />Banvel/Vanquish/Clarity plus 2,4-D at 1 pt + 2 pUA or Banvel/Vanquish/C'larity plus Tordon 22K at I to 2 <br />pt + 0.5 to 1 pUA or Tordon plus 2,4-D at 0.75 pt + 2 pUA 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 Universit}• indicate that 1 pUA of <br />•Tordon (025 Ib) controls spotted knapweed for two to three years, but the weed will reim•ade the area <br />unless other management techniyues are used. <br />Mechanical Control of Uiffused Knapweed <br />If desirable grass competition is evident in ditluse or spo tted knapweed stands, judicious herbicide <br />application that does not injure grasses may allow them t o compete effectively with the weeds. Irrigat <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 lar <br />productive state- Seeding suitable perennial grasses is ne cessary to prevent weed reinvasion <br />Yellow toadflax <br />