As CAAR members know, Blackleg, a significant disease affecting canola crops, can reduce yields, lower quality, and impact profitability. Effective management strategies, beginning with seed selection, can help control blackleg’s impact and protect crop health.

Integrated Blackleg Management Strategy

A successful approach to managing blackleg starts with integrated practices. The blackleg pathogen, which overwinters on infected residue, can spread quickly if crops are not rotated.

Here are some tips for CAAR members to remember and share with the farm customers.

A two-year break between canola crops is essential, allowing residue to decompose and breaking the disease cycle.

Advisors/growers should choose seeds rated “R” (resistant) and regularly rotate varieties to diversify the resistance genes in the field, providing a stronger defense against blacklegs.

Scouting fields regularly helps growers monitor disease levels and assess the effectiveness of their management plan. Ideal times for scouting include at swathing, when symptoms are most visible.

Growers should pull up around 50 plants in a W-pattern and inspect the base of the stem for black discoloration. Disease severity is rated on a scale of 0 to 5, with each level indicating potential yield reduction.  Visit blackleg.ca for further information on blackleg scouting and the disease severity scale.

Additional Management Practices

Fungicides can offer extra protection in high-risk situations. Certain seed treatments can shield seedlings from early infection, while early-season foliar fungicides can help prevent losses.

Remind growers that another key practice is to control volunteer canola and other Brassica weeds, such as wild mustard and flixweed, during non-canola years. These plants can harbour the blackleg fungus, contributing to its spread across fields.