Rangeland and Non-Crop Areas
Medusahead (Taeniatherum caput-medusae) is predominant on millions of acres of semi-arid rangeland in the Pacific Northwest. It is extremely competitive and crowds out other vegetation on infested rangeland, including such undesirable species as cheatgrass or downy browme (Bromus tectorum). A new species in the region is ventenata (Ventenata dubia), that is currently increasing its expansion across the Pacific Northwest. These weedy annual grasses often out-compete bunch grasses that stabilize the soil and provide feed for cattle and other wildlife. Furthermore, medusahead, ventenata and cheatgrass dramatically increase the fuel load, creating hotter, more destructive range and forest fires. They also allow soil structure to deteriorate, setting the stage for increased soil erosion.
Objectives of this research include: 1) evaluate the control of medusahead, ventenata and cheatgrass with herbicides, 2) determine the subsequent effect of herbicides on recovering bunchgrass growth when competition from medusahead, ventenata and cheatgrass are controlled, and 3) evaluate stand establishment of six bunchgrasses following herbicide applications where few bunchgrasses remain.