Blackleg is a serious fungal disease of canola caused by Leptosphaeria maculans. This disease occurs in both mild and virulent forms. Both types are found in North Dakota and many parts of Canada. The virulent strain is economically important as it may cause premature seedling death in the field as well as resulting in canola plants that lodge easier. This disease is seed transmitted.

Symptoms
Tan or brown colored leaf spots are formed on leaf surfaces. Stem lesions can also be found and are gray or black in color. Pods and seed may also become infected. Infected seed may appear gray and have a shriveled appearance. Infected pods have a tendency to split open resulting in seed loss.

Control
Effective control measures for Blackleg in canola include:

• good management practices
• planting resistant varieties
• disease free seed

Testing
Blackleg testing for the virulent strain is conducted by the department. An agar test is performed using 1,000 seed. This test is typically completed in seven days and results are reported as a percentage of infected seed.