Clubroot has been ravaging fields in Western Canada for almost two decades now. The soil-borne disease causes galls to form on the roots of canola plants, eventually killing them prematurely. It’s well documented in intensive clubroot zones that short canola rotations are a serious factor in aggravating the disease and creating conditions for it to thrive, allowing new pathotypes to emerge.
The University of Alberta has identified over 55 clubroot pathotypes in Western Canada, of which many are able to overcome some sources of clubroot resistance. Pathotype 3A is the most common in the region, followed closely by 3H and 3D.
Clubroot is spread easily through soil movement. Root galls release spores back into the soil where they remain dormant until susceptible plants are grown again. So, if you can’t prevent it, what can you do?
BrettYoung’s Clubroot DefendR®: Broad Resistance with a Multi-Genic Approach
Selection of a Clubroot DefendR® hybrid is a strong step in the fight against clubroot. As new pathotypes are identified, plant breeders continue incorporating additional sources of resistance into their latest canola hybrids.
Stacked Resistance Across Multiple Hybrids
Hybrids such as BY 7202LL, BY 7206LL, BY 7204LL, BY 6216TF, and BY 6217TF carry stacked clubroot resistance genes.
These multi-genic combinations provide broad protection by targeting:
- Predominant Western Canadian pathotypes: 3A, 3D, and 3H, which together account for over 60% of identified pathotypes
- Additional common pathotypes: 8E, 8N, 8P, 9E, 8A, 5L, 5G, 8D, and 5C, along with numerous less frequently encountered variants
Ongoing Screening and Adaptation
BrettYoung, through its primary canola genetics supplier DL Seeds, continues to screen clubroot-resistant hybrids against the most common and newly emerging clubroot pathotypes to ensure durability of resistance.
Where Clubroot DefendR Fits Best
Choose Clubroot DefendR hybrids:
- In areas where resistance breakdown is suspected, and
- To help minimize clubroot spore buildup over time
These hybrids perform best when supported by agronomic practices such as crop scouting and crop rotation, which strengthen the long-term effectiveness of resistance.
Clubroot Management Practices
The Canola Council of Canada has a list of recommendations to manage the spread of clubroot spores by focusing on keeping them low and local.
Keep it Low
- Scout frequently: Scout diligently and pull plants to catch early infestation, especially in high traffic or moisture prone areas.
- Crop rotation: Maintain a minimum two-year break between canola crops.
- Grow clubroot-resistant hybrids: Use resistant hybrids on every acre as part of an integrated pest management approach.
- Control weeds: Control host brassicae weeds to minimize gall formation and spore release.
Keep it Local
- Reduce tillage: Cut down soil and pathogen movement within and between fields.
- Practice biosecurity: Use sanitation to prevent introduction and spread of spores.
- Utilize patch management: Address small areas with symptoms by targeted action.
BrettYoung Clubroot DefendR
Clubroot is now established in all three Prairie provinces. Since 2013, when the first resistance-breaking pathotype was identified in Alberta, several new and more virulent pathotypes have evolved that can evade the original source of clubroot resistance.
The Clubroot DefendR trait indicates the canola hybrid has stacked sources of clubroot resistance. This approach signifies resistance to the older, first-identified pathotypes like 3H, but also resistance to other predominant pathotypes like 3A and 3D.
DL Seeds has a robust pipeline coupled to high-performance hybrids that BrettYoung will continue to commercialize to support you in keeping one step ahead of this impactful disease.
FAQ
What is clubroot and how does it affect canola crops?
Clubroot is a soil-borne disease that causes galls to form on the roots of canola plants, leading to premature plant death and significant crop losses.
How is clubroot spread in canola fields?
Clubroot is easily spread through soil movement, as root galls release spores back into the soil where they remain dormant until susceptible plants are grown again.
What are BrettYoung’s Clubroot DefendR hybrids and how do they help?
BrettYoung’s Clubroot DefendR hybrids contain stacked sources of clubroot resistance, offering broad protection against the most common and some less common pathotypes found in Western Canada.
What management practices are recommended to control clubroot spread?
Recommended practices include frequent scouting, maintaining at least a two-year break between canola crops, growing clubroot-resistant hybrids, controlling brassicae weeds, reducing tillage, implementing biosecurity measures and using patch management for localized clubroot symptoms.
