Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Committee Chair(s)

Corey V. Ransom


Corey V. Ransom


Thomas A. Monaco


Earl Creech


Invasive grasses pose a threat to rangeland ecosystems in Utah. Three grasses in particular: downy brome, medusahead, and ventenata can push out native plants and prevent other vegetation from germinating. These grasses can also degrade grazing lands for cattle and act as kindling for wildfires. The use of herbicides is the most common way to rid a site of invasive plants. Herbicides that prevent germination for many years work well to keep annual grasses at bay while not harming the many long-living native plants that are already growing.

A study was designed on a site infested with downy brome to test how well native plants tolerate a variety of herbicides. The main objective was to test for lone herbicides or combinations that do minimal damage to the native vegetation with maximum damage to downy brome.

Ventenata is an invasive grass that is new to Utah; thus, not much is known about how to control it. An experiment was designed to test different herbicides on a site invaded by ventenata and observe the effects on the surrounding native and weedy plants. A concurrent greenhouse study was designed to test three different herbicides on downy brome, ventenata, and medusahead to see how they react differently in controlled conditions compared to field conditions.

An experiment was designed to restore a site that had been completely overtaken by medusahead using herbicides. The site was sprayed with a variety of different herbicides. Native and other desirable plants were planted using a drill into the site in order to see which herbicides prevented medusahead germination while allowing maximum establishment of the plants that were seeded.