Laserfiche WebLink
effective in dissemination of the weed seeds. Currently there is a musk thistle and Canada thistle <br />problem on the ranch property. Below is a listing of weeds present in Rio Blanco County which <br />could become a problem in the future. <br />Rio Blanco County Noxious Weed List <br />Black henbane (Hyoscyamus niger), <br />Common burdock (Arctium minus), <br />Dalmation toadflax (Linaria dalmatica) <br />Field bindweed (Convolwlus arvensis) <br />Hoary cress or White top (Cardaria draba) <br />Leafy spurge (Euphorbia esula) <br />Perennial pepperweed (Lepidium latifolium) <br />Canada thistle (Cirsium arvense), <br />Common mullein (Verbascum thapsus) <br />Diffuse knapweed (Centaurea diffusa) <br />Halogeton (Halogeton glomeratus) <br />Houndstongue (Cynoglossum officinale) <br />Musk thistle (Carduus nutans) <br />Plumeless thistle (Carduus acanthoides) <br />Russion knapweed (Centaurea repens) Spotted knapweed (Centaurea maculosa) <br />Scotch thistle (Onopordutn acanthium & tauricum) Yellow toadflax (Linaria wlgaris) <br />Canada thistle <br />Canada thistle is an aggressive creeping perennial weed that infests pastures, rangeland, <br />roadsides and non-crop areas. Generally, infestations start on disturbed ground including ditch <br />banks, overgrazed pastures, tilled fields, or open waste places. The thistle flowers in late spring <br />and early summer and grows in circular patterns. The thistle develops seed sparingly. Generally, <br />vegetative reproduction from the roots contributes to local spread and seed to long distance <br />dispersal. Seed may be transported by water, or attached to animals, clothing, farm equipment, <br />and other vehicles. Also wind may help disseminate seed. but most often, the feathery pappus <br />breaks off leaving the seed attached to the pazent plant to be disseminated by other means. Seed <br />can remain viable in the soil for up to 20 years and deep burial promotes survival longevity. <br />A successful management system combines control methods. Cultural and chemical methods can <br />be integrated in most situations to control Canada thistle. Mechanical methods can be easily <br />combined with cultural and chemical treatments in most cropping situations including pastures <br />