Virulent Blackleg is a disease that has been a problem for canola producers for many years.


This disease is highly infectious, which impacts yield and reduces crop production. In the early 1990s, canola varieties with high levels of genetic resistance to Virulent Blackleg were introduced, and cultural controls such as crop rotation were adopted by producers.

Unfortunately, these varieties have developed resistance breakdown that has allowed the disease to resurface over the last several years.

Learn more about Blackleg disease and resistance management

What to Look For

Virulent Blackleg disease in canola Virulent Blackleg disease in canola Virulent Blackleg disease in canola

Virulent blackleg in stem                  Stem lesion                                    Canola leaf with pycnidia

  Virulent Blackleg disease in canola  Virulent Blackleg disease in canola

Virulent blackleg severity rating       Stubble infect by pycnidiospores


Although Virulent Blackleg is a major concern for canola production, there are many measures you can take to prevent the spread of the disease:

  • Use a 3-4 year rotation of canola with non-susceptible crops;
  • Scout for disease throughout the growing season;
  • Use certified, treated seed;
  • Rotate varieties of canola seed; and
  • Ensure proper use of fungicides.

Related Links

Canola Encyclopedia Blackleg

Best Management Practices for Blackleg