1a. Objectives (from AD-416):
The overall objective is to develop and implement a comprehensive, regional Ecologically-based Invasive Plant Management (EBIPM) program to restore ecosystems threatened and dominated by cheatgrass/medusahead in Smoke Creek watershed and the Great Basin.
1b. Approach (from AD-416):
University of California, Davis (UC-Davis) and USDA, Agricultural Research Service (ARS) scientists will cooperate on a project to demonstrate the effectiveness of Plateau on the large scale control of downy brome and medusahead, and to determine its utility in sage grouse habitat restoration of desirable native species without the need for expensive re-seeding efforts. Secondly, to consider alternative methods of control with and without re-seeding efforts, and to determine the best seeding method when active restoration practices are necessary (refer to project proposal for more detailed information).
3. Progress Report:
The goal of this project is to develop and implement a regional Ecologically-Based Invasive Plant Management (EBIPM) program to restore ecosystems threatened and dominated by annual grasses in the Smoke Creek watershed which contributes directly to Subobjectives 1.1 and 1.3 of the Area-wide pest management project for annual grasses in the Great Basin. Three different experiments were conducted in Modoc County, California, and data collection occurred a total of 3 seasons after plots were initiated. In these experiments, we were evaluating the control of downy brome and medusahead on a landscape scale by applying herbicides selectively, so as not to damage desired perennial species on rangelands in northern California. We tested the effect of low rates of glyphosate at 3 different treatments timings for medusahead control to determine if low rates of glyphosate applied at key phenological stages of plant growth provided selectivity to native plants while controlling invasive annual grasses. This research can provide additional tools and strategies for land managers to utilize in EBIPM programs. Results show that medusahead cover and seed production decreased when glyphosate was applied at medusahead tillering (late April-early May). The optimum rate where medusahead was adequately controlled and desired species were not damaged was between 4-8 oz., depending on the year of application. These results offer a cost effective treatment for large scale medusahead infestations that address the concerns for restoring sage grouse habitat. Three manuscripts have been accepted by peer-reviewed journals as a result of this research. Outreach associated with this project where results were presented included: A workshop in Reno, Nevada on September 20, 2011 entitled “Cheatgrass and Medusahead Management", presentations at the Western Society of Weed Science, Weed Science Society of America and Society for Range Management annual conferences. All aspects of the project were completed within the timetable established in the proposal.