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Integrated Weed Management Recommendations <br /> Effective integrated management means using a variety of eradication methods along with restoration, prevention of <br /> seed production and dispersal, and monitoring. Maintain robust healthy native landscapes. Restore degraded sites. <br /> Avoid soil disturbance.As with most biennials,prevent seed production in the first and second year of growth. Prevent <br /> seed from dispersing,such as on contaminated equipment. Rest sites until they are effectively restored. Change land <br /> use practices. Use methods appropriate for the site. <br /> CULTURAL CONTROL METHODS <br /> Effectiveness begins with maintaining or restoring a competitive native forb and forb <br /> 4 s assemblage.Continue restoration efforts until native plants are robust and abundant.Use <br /> locally adapted native seeds whenever possible to improve competitiveness. Include cool <br /> season and warm season, as well as perennial and annual grasses in revegetation efforts. <br /> Soil may need to be restored by adding soil amendments,soil microbes,mycorrhizal fungi <br /> and nitrogen fixing plants such as legumes. Manage land uses so they do not create bare <br /> mineral soil or compact soil. Annual crop cultivation appears to be an effective control <br /> "' f 3fXt measure. <br /> BIOLOGICAL CONTROL METHODS <br /> Domestic livestock are likely to avoid this plant due the large number of spines all over the <br /> Q 3 k plant.Goats and sheep may eat flower heads if plants are small. Since most livestock and <br /> y .L herbivores avoid the leaves and stems,Scotch thistle can become an"increaser" in over- <br /> grazed systems.Properly managed grazing systems can increase desireable plant vigor and <br /> indirectly reduce Scotch thistle. There are no known biological control agents effective <br /> against scotch thistle or authorized in Colorado. For more information about biological <br /> control agents,visit the Colorado Department of Agriculture's Palisade Insectary website <br /> Q at www.colorado.goy/ag/`biocontrol. <br /> 7 Jxqui T_umer TheTimaru Herald. <br /> T3 MECHANICAL CONTROL METHODS <br /> GGn n�� C '� ^ ` Methods, such as tilling, hoeing and digging, are best for infestations smaller than 0.5 <br /> ru <br /> �jtJ F acres; weigh this against other plants present, ecology and site condition. Sever roots <br /> below the soil surface during the first year before the plant stores energy and in the second <br /> year before seed production.Mowing,chopping and deadheading stimulates more flower <br /> production;these methods require consecutive years of season-long treatments. Flower <br /> heads must be collected, bagged, and disposed of or destroyed; seeds will mature and <br /> germinate if left on the ground. Fire gives Scotch thistle a competitive advantage. Large <br /> 4-J fleshy stems and leaves would not be consumed in a low severity fire and seeds would <br /> remain unaffected. High severity fires would likely damage native plants, which favors <br /> r,B�go� <br /> O C$ Scotch thistle if seeds are not killed and this is not recommended. <br /> Q CHEMICAL <br /> ENOTE: The following are recommendations for herbicides that can be applied to pastures and rangeland. Rates are <br /> n^ approximate and based on equipment with an output of 30 gal/acre. Follow the label for exact rates. Always read, <br /> understand,and follow the label directions.The herbicide label is the LAW! <br /> L <br /> O HERBICIDE RATE APPLICATION TIMING <br /> CIL <br /> O Aminopyralid*(Milestone) 7 oz.product/acre+0.25-0.5% Apply in spring rosette to early bolting growth stages or in fall to <br /> C v/v non-ionic surfactant rosettes. *Product not permitted for use in the San Luis Valley. <br /> O Chlorsulfuron**(Telar) 1-2.6 oz.product/acre(0.75 oz. Spring from bolting to flower bud stages.**This herbicide <br /> active ingredient/acre)+0.25% has residual soil activity that will affect all broadleaf seedlings <br /> v/v non-ionic surfactant germinating after application has occurred. <br /> Metsulfuron+Chlorsulfuron 2 oz.product/acre+0.25-0.5% Apply during rosette to flower bud stages. <br /> (Cimarron X-tra) v/v non-ionic surfactant <br /> Clopyralid(Transline) 0.67-1.33 pints product/acre+ Apply to rosettes in spring or fall. <br /> 0.25%v/v non-ionic surfactant <br /> Aminocyclopyrachlor+ 4.75-8 oz.product/acre+0.25% Apply from the seedling to the bolting stage. IMPORTANT: <br /> chlorsulfuron(Perspective)* v/v non-ionic surfactant Applications greater than 5.5 oz.product/acre exceeds the <br /> *Product not permitted for threshold for selectivity.DO NOT treat in the root zone of desirable <br /> use in the San Luis Valley. trees and shrubs.Not for use on grazed or feed forage. <br /> Colorado Department of Agriculture-Conservation Services a <br /> 305 Interlocken Parkway pivmi <br /> �Broomfield,CO 80021 <br /> Rev. • (303)869-9030 <br /> 11/16 www.colorado.gov/ag/weeds <br />