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 2-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 aboveground foliage of sulfur cinquefoil.
Objective 1: The results from Objective 1 were presented at the annual meeting of the Society for Range Management and the Montana Weed Control Association Annual Meeting. A manuscript to be submitted to Rangeland Ecology and Management is in the preparation phase.
Objective 2: Final laboratory work was completed on Objective 2. Recovery of seeds was greatest in the first 2 days following consumption. The viability of recovered seeds declined steadily for seeds recovered from both sheep and goats as the days to recovery increased. No viable seed was recovered from either species later than day 4 following ingestion. The potential for grazing animals to pass viable seed when consuming sulfur cinquefoil at the “green” seed stage is minimal. Dry-lotting animals that graze sulfur cinquefoil seedheads containing mature seed for 4 days should eliminate transfer of viable seeds to uninfested areas. The results of this project were presented at the Society for Range Management Meeting and at subsequent training modules for BLM employees. A manuscript is being prepared for Invasive Plant Science and Management.
Objective 3: Laboratory procedures and facilities for tannin analysis are being explored.
Field and laboratory work have been completed for Objective 1. Field work has been completed for objective 2 and laboratory work continues. Final data analysis continues. Results from Objective 1 were presented as a poster at the annual meeting of the Society for Range Management, to the Joe Skeen Institute for Rangeland Restoration and to sheep producers.
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 this WSARE project are the foundation of this body of research that will result in a complete targeted grazing prescription for sulfur cinquefoil.