Best Management Practices for Noxious Weeds of Mesa County General rules for management practices for noxious weeds of Mesa County. Control recommendations for species on the Mesa County Noxious Weed List and Noxious Weed Biology Table.

Gray Rabbitbrush Control Following Applications of Redeem R&P and Crossbow Herbicides - [Chrysothamnus nauseosus (Pallas) Britt.]
Gray rabbitbrush, Chrysothamnus nauseosus (Pallas) Britt., is a strongly scented perennial plant that has many branches. The stems are silky or white woolly covered and range in height from 2 to 4 feet. The flowers are in large clusters at the tips of the stem and yellow in color. Information provided by A. Wayne Cooley (deceased), former Area Extension Agent (Area Director & Soil and Crop Science).

Canada Thistle Control Following Applications of Curtail and Redeem R&P Herbicides - [Cirsium arvense (L.) Scop.]. Canada thistle, Cirsium arvense (L.) Scop., is an aggressive creeping perennial, that once established, becomes very competitive in irrigated pastures and mountain meadows. Canada thistle is also on the state of Colorado and Tri River Area counties noxious weed list. Information provided by A. Wayne Cooley (deceased), former Area Extension Agent (Area Director & Soil and Crop Science).

Cuscuta and Grammica species - Dodder is a twining yellow or orange plant that parasitizes various kinds of wild and cultivated plants. A photograph of this parasite, discussion and control are provided.

Leafy Spurge Control Following Herbicide Applications in the Tri River Area. Leafy spurge is native to Eurasia and was brought into the United States as a seed impurity around 1827. Leafy spurge seems to be a serious problem only in North America where it infests almost 2.5 million acres. The greatest infestation is primarily in southern Canada and the north central United States. Leafy spurge is found in several areas of Colorado and has become more wide spread in the Tri River Area in the past few years. Information provided by A. Wayne Cooley (deceased), Area Extension Agent (Area Director & Soil and Crop Science).

Russian Knapweed: Control Following Applications of Curtail and Redeem. [Acroptilon repens (synonym = Centaurea repens)] is a deep rooted creeping perennial plant that was first introduced into North America in about 1898. Russian knapweed grows in a variety of soil types and is not associated with any particular soil. Much of the initial invasion of this plant has been traced to contaminated alfalfa seed that was imported from Russia in the 1920's. More recent spread of Russian knapweed seed can be attributed to several different means including motorized vehicles, contaminated gravel for road surfacing, irrigation water, farm equipment, as well as humans, birds, and mammals. Information provided by A. Wayne Cooley (deceased), former Area Extension Agent (Area Director & Soil and Crop Science).

Sweet Corn - Band and Broadcast Applied Herbicides in the Tri River Area. Herbicide weed control is one component of production agriculture. Available herbicides should be evaluated periodically to determine crop tolerance and the best product for the weed species present. The population of weed species can change over time, especially if the same product is used year after year. The more available herbicides we have to choose from can, in some cases, provide more consistent weed control and/or allow us more flexibility in our crop rotation. Information provided by A. Wayne Coole (deceased) former Area Extension Agent (Area Director & Soil and Crop Science).

Whitetop (Hoary Cress) Cardaria draba is a deep rooted creeping perennial mustard plant. It is very aggressive and will eventually crowd out desirable vegetation if not controlled. Information provided by A. Wayne Cooley (deceased), former Area Extension Agent (Area Director & Soil and Crop Science).

Yellow Starthistle - Centaurea solstitialis L. is a plant of Old World origin that is believed to have arrived in California in the mid-1800's as a contaminant in alfalfa. It is a member of the sunflower family (Asteraceae) and belongs to the thistle tribe (Cynareae). Since its introduction, yellow starthistle has spread steadily and was estimated to inhabit about 8 million acres in California by 1985. In 1999 it was estimated that California had 22 million acres of yellow starthistle. Information provided by A. Wayne Cooley (deceased), former Area Extension Agent (Area Director & Soil and Crop Science).

Tamarisk - (Tamarix spp.) Tamarisk (Tamarix spp.) is native to central Asia. In the late 1800s, eight tamarisk species were brought to the United States for erosion control and to be used as ornamentals, windbreaks and shade trees. In Western Colorado tamarisk has no natural enemies such as insects or diseases to keep its population in check. This has allowed it to spread unchecked along western waterways.