Is Sulfur Cinquefoil a Candidate for Control with Sheep and Goats?
Sulfur cinquefoil (Potentilla recta) is long-lived perennial weed that is a prolific seed producer and is adapted to nearly every soil type and vegetation complex in the western U.S. This invader reproduces solely by seed, and a single plant can produce as many as 6,000 seeds annually. The purpose of this two-year study was to determine the optimal timing and intensity of defoliation to decrease plant yield and seed production of sulfur cinquefoil plants on foothill rangeland in southwestern Montana. The effect of sheep and goat ingestion on the germination and viability of sulfur cinquefoil (Potentilla recta L.) seeds was also investigated, as well the tannin content of above ground foliage of sulfur cinquefoil.
Objective 3: Plant material was collected in another attempt to analyze the seasonal tannin content of sulfur cinquefoil. Additional plant material was collected and sent in September to a laboratory in Texas to develop a tannin standard specific for sulfur cinquefoil. Once the standard is developed, plant samples will be freeze dried and sent to Texas for analysis. The tannin analysis should be completed by early spring, and data analysis and manuscript preparation will follow.
Objective 4: R. Frost and J. Mosley continue to present results from this portion of the project at annual BLM training events and weed education workshops. A manuscript of the findings of Objective 1 has been prepared and will be submitted to “Rangeland Ecology and Management” in February 2011. A manuscript for Objective 2 is being prepared for “Invasive Plant Science and Management” and should be submitted in April 2011. A field day is planned for August 2011 detailing the findings of this project and the potential to use actual livestock grazing to suppress sulfur cinquefoil. This field day will include the local weed district supervisor and board members, county and tribal extension agents, and interested producers and landowners.
Field and laboratory work have been completed for Objectives 1 and 2. Results from Objective 1 and 2 have been presented at the annual meeting of the Society for Range Management, the annual meeting of the Montana Weed Control Association and the Sheep Advisory Council for Montana State University. The results of this project have been incorporated into a training protocol for Bureau of Land Management employees seeking pesticide application certification and for many local certification programs offering continuing education credits.
Field work is completed for Objective 3, and laboratory and data analysis continues.
Impacts and Contributions/Outcomes
Results from the clipping trial in Objective 1 demonstrate that defoliation is an effective method to decrease seed production of sulfur cinquefoil. This information has been used to successfully obtain funding to conduct a large-scale grazing project in cooperation with the Confederated Salish-Kootenia Tribes to determine if sheep will consume sulfur cinquefoil. Preliminary results indicate that sheep readily consume the plant and are capable of reducing the viable seed introduced to the soil by 96% compared to controls. The funds received from Western SARE project are the foundation of this body of research that will result in a complete targeted grazing prescription for sulfur cinquefoil.