Clubroot is a serious soil-borne disease of cruciferous plants, such as canola. In canola, it causes swellings or galls to form on the roots, which ultimately causes premature death of the plant. It is caused by a fungus-link protist called Plasmodiophora brassicae.
- Video: How to Scout for Clubroot
The Provincial Plant Disease Specialist and a Crops Extension Specialist with Saskatchewan Agriculture walk you through how to scout for clubroot in your canola fields.
The key to clubroot management is to keep spore levels as low as possible.
To do this, clubroot needs to be managed through an integrated approach. In any field, clubroot management will be effective in minimizing the spread and severity of clubroot.
Further clubroot management strategies are advisable when spore levels are high or when you feel a higher level of caution is warranted.
Clubroot Best Management Practices
- in fields where clubroot has not been confirmed: rough clean equipment to remove soil before leaving each field
- in fields where clubroot has been confirmed: completely remove all soil and sanitize equipment before leaving each field
- do fieldwork in clubroot-infested fields last
- ensure clubroot-positive fields have separate entrance and exit, with a grass patch at the exit for equipment cleaning
- Crop rotation and weed control
- Use a minimum 3-year rotation
- Control canola volunteers and clubroot-susceptible weeds
- Variety selection
- Ensure early development of clubroot-resistant varieties in extended crop rotations
- monitor all canola crops, including clubroot resistant varieties for visible symptoms
- conduct clubroot soil tests to monitor spore level changes; soil should be collected from the same location and at the same time of year
- Contain clubroot infested areas
- seed clubroot infested areas to a sod-forming grass
- if patch is small, consider pulling and disposing of infected plants
- treat clubroot infested area with lime to increase pH
- Video: Clubroot Management
This video focuses on key management strategies to minimize the risk of introducing the disease-causing pathogen to your farm, slowing the spread of it within your farm if it arrives, and using a multi-pronged approach to reduce the impact from it once the pathogen has been established. Video funded by the AB, SK, and MB canola grower groups.
Developed by the Saskatchewan Clubroot Initiative – last updated August 2019
Monitoring Clubroot in Saskatchewan
This year, we’re ensuring that growers have the tools they need to detect clubroot on their farm at low levels through the 2020 fall clubroot soil testing program, offered by SaskCanola and the Saskatchewan Ministry of Agriculture. As part of this program, a grower can request a soil sampling bag, collect soil from their field and submit it for testing at no cost. Results will be kept confidential and will only be shared with the rural municipality if they have enacted a clubroot bylaw. All findings of clubroot and the clubroot pathogen will be added to the Saskatchewan Clubroot Distribution map (at an RM level) to raise awareness of the presence of clubroot and to guide proactive biosecurity and management decisions. Because of the value that these test results will provide growers and the industry, SaskCanola will cover the $100 cost of each test.
How to Get a Clubroot Soil Test
There are different ways that you can request a soil test:
- Sign up online and Sask Agriculture will send a soil testing bag to you
- Contact the SaskCanola office
- Contact your local SARM Plant Health Officer; or
- Contact your local Ministry of Agriculture Regional office
*Agronomists who would like to have a bundle of soil testing bags on-hand for clients, should contact SaskCanola.
When to Sample
Soil samples should be collected in late summer or around swathing time. This is when clubroot galls start decomposing and releasing spores back to the soil.
Where to Sample
To reduce the risk of a false negative, it is important to collect soil from high clubroot risk areas. These areas include field entrances, high-traffic areas, water runs and low spots.
Submitting the Sample
Soil samples can be dropped off at your local Ministry of Agriculture regional office or at Discovery Seed Labs (Saskatoon). Make sure that the information form on the sample bag is completely filled out.
Getting the Results
The results will be available in early winter, and a ministry staff member will contact you via email or phone with your results. Please be aware that the results will be kept confidential and will only be shared with the appropriate RM office if the test is positive for clubroot and if the RM has a clubroot-specific bylaw enacted.
For More Information
Please contact your Crop Extension Specialist or call the Agriculture Knowledge Centre’s general inquiry line toll-free at 1-866-457-2377.
- Research Project: Evaluation of clubroot disinfectants
Key Result – Bleach is most effective in killing clubroot spores at concentrations above 1.7%. Spray Nine was almost as effective, while 5 other products achieved greater than 95% control.
- Research Project: Developing canola germplasms with diverse mechanisms to enhance the durability of clubroot resistance
Key Result – Researchers successfully developed a range of new and improved canola germplasms carrying single/multi clubroot resistance genes against the new strain of P. brassicae pathotypes 5X.
- Research Project: Identification and genetic mapping of Brassica napus for resistance to pathotype 5X of Plasmodiophora brassicae
Key Result – Researchers identifed more than 10 B. napus lines highly resistant to pathotype 5X, and five to pathotypes 3A, 2B, 3D, and 5X through screening 845 B. napus lines collected worldwide. Two new genetic regions of resistance associated with resistance to pathotype 5X were identified through genome-wide association mapping of resistance to clubroot. One of the best resistant lines has been distributed to canola seed companies.
- Research Project: Enhancing the durability of clubroot resistance with multiple genes
Key Result – The study highlighted the value of using stacked clubroot restance genes of different modes of action for resistance performance and durability.