Laserfiche WebLink
Management <br />Cultural control of Plumeless Thistle <br />Maintaining pastures and rangeland in good condition is a primary factor for Plumeless thistle management. To favor <br />pasture and rangeland grass growth, do not overgraze. Fertilize only when necessary and according to soil testing <br />recommendations. To successfully manage Plumeless thistle, prevent seed formation. <br />Mechanical control of Plumeless Thistle <br />Plumeless thistle will not tolerate tillage and can be removed easily by severing its root below ground with a shovel or <br />hoe. Mowing can effectively reduce seed output if plants are cut when the terminal head is in the late - flowering stage. <br />Gather and burn mowed debris to destroy any seed that has developed. <br />Chemical Control of Plumeless Thistle <br />Several herbicides are registered in pasture, rangeland and noncrop areas to control Plumeless thistle. Tordon 22K <br />(picloram), Curtail (clopyralid +2,4-D), Banvel/Vanquish/Clarity (dicamba), 2,4D, or BanveWanquish/Clarity plus <br />2,4-D are commonly used. Apply these herbicides in spring or fall to Plumeless thistle rosettes. <br />Apply Tordon at 0.5 to 1 pint per acre (A), Curtail at 2 quarts/A, BanveWanquish/Clarity at 0.5 to 2 quarts/A, 2,4D at <br />1.5 to 2 quarts /A, or BanveWanquish/Clarity plus 2,4-D at 0.5 plus 1 quart/A. Cool temperatures (below 50 degrees F), <br />particularly in fall, may adversely affect 2,4-D control of Plumeless thistle; therefore, use 2,4-D in spring. Tordon is <br />largely unaffected by cool tom. BanveWanquish/Clarity can be adversely affected but less than 2,4-D. <br />BanveWanquish/Clarity plus 2,4-D works well in spring or fall. Apply any of these herbicides before Plumeless thistle <br />bolts or seed production still will occur. <br />Ally -Escort (metsulfuron) or Telar (chlorsulfuron) also can be used. Use Telar in noncrop areas only and Ally - Escort in <br />pastures, rangeland or noncrop areas. Research from Colorado State University and the University of Nebraska shows <br />that Telar or Ally - Escort prevents or dramatically reduces viable seed formation when applied in spring, up to early <br />flower growth stages. The latest time to apply these herbicides is when developed terminal flowers have opened up to <br />the size of a dime. <br />Apply Telar at 1 ounce/A or Ally - Escort at 0.5 ounce/A. Add a good alai surfactant at 0.25 percent v /v2 to Ally - <br />Escort or Telar treatments or control is inadequate. <br />