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  • Clubroot R breakdown: Preliminary results from 2014 survey

    Stephen Strelkov with the University of Alberta tested soil samples from 27 fields in Alberta that were seeded to resistant varieties in 2014 and showed more than expected levels of gall formation. Of those 27 fields, 15 have clubroot pathotypes that suggest the clubroot in those fields had overcome the resistance trait.


  • What is “intermediate” disease resistance?

    A new canola variety was recently registered claiming an “intermediate” reaction to clubroot pathotype 5x, as well as resistance to established clubroot pathotypes 2, 3, 5, 6 and 8. Based on Western Canada Canola/Rapeseed Recommending Committee protocol for clubroot disease resistance, seed that is resistant (R) shows less than 30% infection based on a severity-by-incidence rating, and seed that is susceptible (S) will have more than 70% infection. An intermediate (I) reaction is somewhere in the middle.

    A variety with intermediate reaction to 5x is not recommended on fields infected with the 5x pathotype. A minimum four-year rotation for canola is still recommended on these fields.


  • Blackleg resistance vs. clubroot resistance

    This is a clubroot infested field, with a resistant variety grown on the left and a susceptible variety grown on the right. Source: Aaron Van Beers

    Growing clubroot resistant varieties in areas with low levels of inoculum or areas beside regions known to have clubroot is a good pre-emptive strategy to keep clubroot to a minimum in a particular field. The question for growers in areas with serious blackleg is whether to grow varieties with effective blackleg resistance or grow varieties with clubroot resistance. Current varieties do not always offer both. Some considerations when making the decision…


  • Clubroot shift and crop rotation

    Example of clubroot galls found at harvest time.

    Discovery of a different clubroot pathotype in central Alberta will change the rotation plans for some growers. No current varieties have resistance to this different pathotype, and varieties with a new effective source of resistance will not be available for at least the next year or two, or maybe longer. Longer rotation is necessary to slow the pathogen shift that is occurring in these fields.


  • Clubroot survey underway

    Alberta has started an intense survey to check fields for clubroot pathotype 5x, which is able to overcome all forms of resistance on the market today. The survey will focus on suspicious patches in fields that were grown to an R-rated canola variety. Growers and agronomist who spot suspicious patches in a resistant variety, can contact their County Ag Fieldman to be part of the survey. The point is to map the extent of this new pathotype.

    Further reading:
    Clubroot pathogen shift: Management


  • Clubroot pathogen shift: Management

    In 2013, an Alberta field was identified where a clubroot resistant variety showed a high incidence of clubroot infection. Subsequent testing by the University of Alberta indicated that all current forms of resistance were not functional on the disease in this soil. This failure of resistance or its breakdown was determined to be due the increasing shift to a previously unidentified pathotype called 5x. Current clubroot resistance is still functional to the predominant pathotype 3 and the less dominant pathotypes 6, 5 and 8. But this 5x is able to overcome all forms of resistance on the market today.


  • Soil sampling for clubroot

    Decaying clubroot galls

    Various labs will test soil for clubroot. Those collecting soil samples are advised to park on the road when possible so the vehicle does not pick up infested soil. Follow sanitation procedures if visiting more than one field. This includes using disposal boot covers for each field and cleaning and disinfecting footwear and tools that come in contact with the soil. MAFRD provides these soil sampling procedures…


  • Disease scouting: killing two tasks with one look

    While you are out there checking to see if your crop is ready to cut/harvest is a perfect time to also check for disease! Likewise, the representative sampling technique used to accurately determine the stage of the crop is also ideal for disease scouting of your field. Pulling out a few plants and checking for the big three diseases, as well as any other issues, will save you an extra trip to the field. Early disease detection could save you thousands of dollars down the line!


  • Clubroot in North Dakota

    A severe case of clubroot has been found in a canola field in North Dakota, near the Manitoba border. This suggests the disease has been in the area longer than expected. It also confirms expectations that environmental conditions in Manitoba are suitable for clubroot. Close scouting is advised for growers in Manitoba and Eastern Saskatchewan, especially canola fields close to the North Dakota border.


  • Different clubroot pathotype confirmed

    Canola with small developing clubroot galls. Source: Stephen Strelkov

    Research has confirmed the presence of a different clubroot pathotype in the Edmonton region and none of the commercially available clubroot resistant varieties in Western Canada are effective at managing it.

    Stephen Strelkov, the University of Alberta researcher leading this project, has identified other resistance genes that could work, but they are not currently in commercial hybrids.


  • Clubroot is a soil problem, not a canola problem

    Any step that moves soil will move clubroot. It doesn't matter what crop is growing or what time of year it occurs.

    Clubroot-resistant canola is the best tool available to limit disease damage in fields infested with clubroot. However, an effective overall clubroot management strategy has to be top of mind in all years, not just canola years.

    As a soil borne disease, clubroot can spread no matter what crop is grown on a field. Any pass with the drill or cultivator, for instance, will pick up and move soil — and, therefore, clubroot spores. Even with a one in four canola rotation, clubroot can be spread all around the farm in the intervening years.


  • Clubroot found in Manitoba canola

    Small clubroot gall found in Manitoba in 2013.

    Manitoba has had two canola fields confirmed this month to have clubroot symptoms on plants. Last year, clubroot was confirmed in two soil samples in the province, but plant symptoms were not observed.

    Clubroot is expected to spread across the Prairies eventually. The disease was first detected in Manitoba in vegetable crops in 1925. It is not a surprise to find it in canola fields. The key is to become more aware of the disease, what it looks like, how to scout for it, and how to prevent its spread. With early detection, use of resistant varieties and equipment sanitation practices to keep it from moving around, growers can manage the disease.


  • More clubroot management tips

    Soil is more likely to cling to wheels, openers and frames when conditions are wet.

    Early detection makes clubroot easier to contain. By the time patches of clubroot infection are obvious in fields, clubroot spores may have been present for a while and may have already spread to neighbouring fields. Clubroot disease management plans will vary depending on the amount of disease and its severity, but growers in all regions should watch for the disease.

    Read more for prevention and management tips for infested and non-infested land.


  • Top 10 tips from the 2013 International Clubroot Workshop

    International Clubroot Workshop logo

    1. Have a plan to manage clubroot. Don’t wait until clubroot manages you. Whether you’re a farmer, agronomist, county/municipal staff, extension, or from the oil & gas industry, you need a clubroot management plan. A plan should include answers to the following: How will you quarantine a field? How will you plan your field work? When will you sanitize your equipment? When will you use resistant varieties? Visit for help with your plan. Read more to see the other 9.


  • Clubroot Workshop for growers, agronomists, municipal staff

    The International Clubroot Workshop June 19-22 in Edmonton includes one day — Friday, June 21 — dedicated to clubroot extension. This is the day when growers, agronomists, municipal and county staff learn the latest in clubroot management, prevention and mitigation. Cost is $150 per day, and you are welcome to attend the whole workshop, space permitting.


  • Attend the International Clubroot Workshop

    The Canola Council of Canada (CCC) and Agriculture and Agri-Food Canada (AAFC) will bring together a global network of leading researchers and academics to exchange information and research results at the 2013 International Clubroot Workshop in Edmonton, June 19-22. The workshop will have practical value for anyone, including growers and agronomists across the Prairies.


  • Clubroot management: Wet soil increases risk of spread

    Soil on seeding equipment is a key vector for the movement of clubroot spores from field to field. Cleaning dirt from equipment before leaving a clubroot-infested field is a good disease management practice. Avoid working in known clubroot-infested fields when soil is wet and more likely to stick to equipment.


  • Clean new equipment: Keep clubroot at bay

    If you don’t have clubroot, be sure any used or demo’d equipment you buy is clean before you bring it home. Clean equipment before it leaves the auction site or the farm it comes from. Also check that the transport truck is clean. As a precaution, you may want to pressure wash the equipment again when it gets to your farm.


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