It’s been almost a two-decade-long fight against clubroot, and the battle is ongoing. The soil-borne disease has been killing canola plants in Canada since it was first discovered near Edmonton, Alberta in 2003. Since then, it has spread to over 3,000 fields in Alberta and several fields in Saskatchewan and Manitoba, with spores waiting in the soil to infect more.
How Clubroot Infects and Damages Canola
Clubroot causes swellings or galls to form on the roots of canola plants, ultimately causing premature plant death. It is caused by a fungus-like protist that targets brassica roots. Galls can release spores that survive for up to 20 years and later germinate to produce zoospores that infect new plants.
Pathotype Diversity Across Western Canada
As of 2018, 36 clubroot pathotypes have been found in Canada, though this number continues to increase as new variants are identified through ongoing monitoring.
- Alberta: Most common are 3A, 3D, 3H
- Saskatchewan: Most common are 3H and 5L
- Manitoba: 9B, 6D, 13A, 13B, 3A, 2C, 8D, 3H and 5L across 9 of 10 surveyed fields
Pathotype 3A remains the most common in Western Canada, followed by 3H and 3D.
Managing an Infested Field
There are currently no economical control measures to remove clubroot once a field is infested. However, growers can still reduce spread and severity by minimizing soil movement, following a sanitation plan, scouting fields, controlling weeds, using crop rotation, applying patch-management strategies, and planting clubroot-resistant hybrids.
Practices That Help Limit Clubroot Spread
- Minimize soil movement between fields
- Clean equipment and footwear between sites
- Scout fields regularly for early symptoms
- Remove brassica weeds that host the pathogen
- Rotate with non-host crops to reduce spores over time
- Contain infected patches
- Use hybrids with clubroot resistance
BrettYoung Hybrids With Clubroot Protection
BrettYoung offers five products with clubroot protection, including four with DefendR®-rated next-generation resistance. The DefendR designation signals durable genetic resistance to two of the most economically significant diseases in canola: clubroot and blackleg.
Glen Hawkins, Senior Agronomist and Pulse Research Manager for DL Seeds, described the BrettYoung–DL Seeds hybrid lineup as a “solid next-generation package.”
“At the end of the day, we’re not stopping there,” he said. “We’re always developing new genetics and new potential forms of resistance to bolster what we already have.”
Current Clubroot Status in Western Canada
Hawkins noted that Alberta remains a hotspot for clubroot, while Manitoba is beginning to catch up. First-generation and next-generation clubroot-resistant products continue to perform as expected, offering multi-pathotype specificity.
“The gene we insert won’t have just 3C or 3A,” Hawkins explained. “It’ll have full or partial resistance to a number of different pathotypes.”
Advancements in Research and Monitoring
The story of clubroot continues to evolve. Compared with five years ago, understanding of the disease has advanced significantly. Looking ahead, the next five years are expected to provide even more insight as DL Seeds continues developing new tolerance genes and strengthening resistance to key Western Canadian pathotypes: 3H, 3D and 3A.
Where Clubroot Resistance Research Is Heading
- Ongoing investment in identifying new resistance sources
- Continued development of tolerance genes to address emerging pathotypes
- Focused resistance toward the three most significant pathotypes (3H, 3D, 3A)
- Collaboration with the Canola Council of Canada and industry partners
Why Continued Research Matters
Hawkins emphasized that pathotype evolution means the disease will eventually find ways around current resistance sources. This is why DL Seeds continues screening and re-evaluating genetics to keep resistance packages strong.
“I truly think that we have one of the best clubroot packages out there,” he said. “But genetics alone won’t keep the problem at bay.”
Supporting Long-Term Clubroot Management
- Ongoing genetic screening ensures resistance stays effective
- Existing hybrids are retested as new pathotypes emerge
- Integrated management strengthens genetic resistance
- Breeding programs remain flexible to adapt to new threats
The Role of Crop Rotation
Hawkins emphasized that growers must maintain a good crop rotation plan — a practice he has seen work effectively in managing clubroot.
Best Practices for Keeping Clubroot Managed
- Rotate crops to avoid repeated brassica planting
- Extend rotation intervals to reduce spore buildup
- Pair resistant hybrids with strong agronomic management
FAQ
What is clubroot and how does it affect canola plants?
Clubroot is a soil-borne disease caused by a fungus-like protist that forms swellings or galls on the roots of canola plants, causing premature plant death.
How widespread is clubroot in Western Canada?
Since its discovery in Alberta in 2003, clubroot has spread to over 3,000 fields in the province as well as several fields in Saskatchewan and Manitoba.
Are there effective ways to remove clubroot from infested fields?
There are currently no economical control measures to remove the pathogen from a field once it becomes infested but its spread and severity can be reduced through practices like sanitation, crop rotation and using resistant hybrids.
What are pathotypes and which are most common in Western Canada?
Pathotypes are variations of the clubroot pathogen. As of 2018, 36 have been found in Canada, with 3A, 3D and 3H being the most common in Western Canada.
What efforts are being made to protect canola crops from clubroot?
Efforts include the development of clubroot resistant canola hybrids, such as those from BrettYoung and DL Seeds as well as ongoing breeding for new genetics and improved resistance.
Why is it important to continue developing new clubroot-resistant products?
The evolution of clubroot pathotypes means the disease can eventually overcome existing resistance so ongoing research and product development are essential to stay ahead of new threats.
Besides genetics, what other practice is important for managing clubroot?
Having a good crop rotation plan is important for managing the disease along with other integrated management practices.
