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Utah State University Extension

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Invasive noxious weeds have been described as a raging biological wildfire – out of control, spreading rapidly, and causing enormous economic losses. Millions of acres in North America have been invaded or are at risk of being invaded by weeds, including cropland, pastures, rangelands, forests, wilderness areas, national parks, recreation sites, wildlife management areas, transportation corridors, waterways, wetlands, parks, golf courses, even yards and gardens. Noxious weeds are capable of spreading at rates of up to 60% annually (Smith et al. 1999).

Devastation caused by noxious weeds is enormous. Economic losses from weeds exceed $30 billion (Pimentel et al. 2005) annually in the United States, and the cost continues to grow. Weeds often reduce crop yields, and can damage watersheds, increase soil erosion, negatively impact wildland plant and animal communities, and adversely affect outdoor recreation. Ecological damage from uncontrolled noxious weed infestations can be permanent, leaving lands unable to return naturally to their pre-invasion condition.

The weeds included in this guide are legally denoted as noxious according to Utah state law (Code 4-17). Through a structured decision-making process, and with the use of a prioritization tool to help guide the process, the current noxious weed list was determined. The process was biased toward weed species that currently have limited state-wide distribution, and also included those that have not yet been identified as occurring within the state. Because weed management focused on newly invading species, it holds the most promise for effective management.

Prevention, preserving, and protecting lands not presently infested is the first line of defense against aggressive noxious weeds. Prevention requires awareness and action by land managers as well as the general public, to recognize, report, and control new infestations before they have a chance to expand and spread.

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Agriculture Commons



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