Canola Virulent Blackleg

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.

What To Look For

Virulent Blackleg stem lesions Canola leaf with pycnidia
Virulent Blackleg severity rating Stubble infected 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
  • Proper use of fungicides