Thistle Rust Bio-Control

Published: 2020
By Katie Hatlelid

In the summer of 2020, Judith Basin County MSU Extension was able to partner with the Montana Biological Weed Control Coordination Project on another exciting opportunity. A 5-year study of Puccubua punctiformis, a naturalized rust fungus that attacks Canada thistle, has been launched in the state of Montana. Canada Thistle is a common noxious weed in the county, costing thousands of dollars to control and preventing thousands of acres of pasture and hay ground from reaching its full forage production potential. Any type of measure that is cost-effective and offers a good degree of control has the potential to save each producer several hundred to several thousands of dollars per year depending on the degree of infestation. It also has the potential to increase the production of the pasture, hay, or crop land that may be affected. Reducing the competition for desirable plants is key to a high-producing stand. The potential for success is promising, and the inoculation locations in Judith Basin County will help researchers determine the feasibility of using this rust in widespread applications.