INTEGRATED INVASIVE SPECIES CONTROL, REVEGETATION, AND ASSESSMENT OF GREAT BASIN RANGELANDS
Location: Great Basin Rangelands Research
Title: Control of Downy brome (Bromus tectorum) and Medusahead (Teaniatherum caput-medusae) with Rangeland Herbicides in Northeastern California.
Submitted to: Society for Range Management Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 22, 2009
Publication Date: February 8, 2010
Citation: Zhang, J., Kyser, G.B., Wilson, R., Creech, E., Weltz, M.A., Clements, C.D., Ditamosa, J.M. 2010. Control of Downy brome (Bromus tectorum) and Medusahead (Teaniatherum caput-medusae) with Rangeland Herbicides in Northeastern California [abstract]. Society for Range Management Meeting Proceedings. 62:9.
Downy brome (Bromus tectorum) and medusahead ((Teaniatherum caput-medusae) are the two most problematic invasive annual grasses in the western United States. In this study we evaluated the effect of three fall and one spring application of herbicide as well as herbicide combinations on the control of these two invasive annual grasses in Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis) communities in northeastern California. We applied the herbicide treatments in the fall of 2008 and the spring of 2009 at two locations (8 km apart) using a complete randomized block design with four replications per site. Each plot was 30 x 30 m and herbicide applications were made using a back-pack sprayer. The herbicide applications included imazapic 93 g ae/ha, rimsulfuron 17.5 g ae/ha, combination of sulfometuron and chlorsulfuron 35 and 17.5 g ae/ha, and glysophate 420 g ae/ha. Glysophate was the spring application and was applied in mid-April 2009. Plots were evaluated in May and June 2009. Plant species density and cover was estimated using point-intercept transects. Plant biomass weights were taken and recorded for each plot. The herbicide combination Sulfometuron and chlorsulfuron provided 100% control of the two annual grasses at both sites, but also damaged resident established perennial grasses and caused damage to shrub species such as sagebrush. In contrast, rimsulfuron gave 100% control of downy brome and 96% control of medusahead without damaging perennial grasses and shrubs. Imazapic and glysophate were inconsistent, providing between 29% and 100% control of the two annual grasses. Our results indicate that rimsulfuron is very effective in controlling invasive annual grasses such as downy brome and medusahead without damaging existing perennial vegetation. More research is needed though in further investigating the effects of soil types and precipitation levels.