Looking for Canada thistle fungus release sites in Jefferson Co.

The Whitehall Biological Weed Control Project is up and running this season, modified a bit due to COVID-19.  The first step is looking for eight to 10 Canada thistle fungus release sites.  This will include two visits to each site, (May/early June) to set up a long-term sampling transect.  The second visit will be in September/October to infect the plants with the fungus.  Many Montana sites are showing fairly severe damage to the Canada thistle patches the season after the initial release.

The Canada thistle rust fungus (Puccinia punctiformis) is being used in several western states to help control this thistle invader from Europe (the thistle it is not from Canada…).  Since the fungus is a new bio-agent, all the sites will be monitored for a number of years and residents need to be willing to allow the collection of infected plants from the site to make new inoculum for further releases around the state.  

How the project works: