Extension Service gives presentation on Clubroot of Canola

The North State University Extension Service gave presentations last week concerning Clubroot of Canola, a potentially devastating pathogen that could wipe out canola crops.


Posted on 8/23/14

By Melissa Anderson

Ron Beneda, the Cavalier County Extension Agent gave presentations to large crowds on Tuesday and Thursday morning about the pathogen that has had devastating effects on the Canadian canola crop and now threatens to lay claim to North Dakota’s.

Clubroot is a soil pathogen  that “infects the roots of canola and other Brassicae plants (such as broccoli, cauliflower, Shepherd’s purse, and wild mustard)causing galling and swelling, and giving them a “club” appearance.”

The pathogen was first discovered in 2003 in Alberta, Canada. Since then, it has made its way across Canada and now evidence of it has been found in Cavalier County fields.

The pathogen is in the soil, so anything that moves soil can move the pathogen. This pathogen also travels by wind and water, the most likely cause of its arrival in the States being that of farm equipment.

Beneda began the presentation by explaining what types of conditions favor Clubroot.

“ This stuff loves low pH levels, which means we are lucky because our pH levels are higher.”

Warm temperatures and wet soil also helps this pathogen thrive.

The appearance of Clubroot often begins with small patches in fields.

“The canola may be stunted, yellow, and generally unhealthy looking and the stand may be thin. The roots of the plants that have been infected will be swollen and shaped like clubs.” Those plants that are infected will be very easy to pull from the ground.

Beneda cautions farmers against uprooting plants and bringing them into the extension office.

“The worst thing you can do is grab samples and bring them into the coffee shop and show guys or bring them into the office.”

Currently, the Extension Service is in contact with the Canadian Canola Counsel trying to determine what strain the pathogen found in ND is.

The Extension Service will be in contact with the Canola Counsel to determine how big of a radius will be needed to inform farmers of contaminated fields.

The resting spores have a life span of up to 20 years  and have a half life of four to five years.

“That’s why this is so significant, it’s not like one, two, three years of rotation and it’s not a problem anymore” Beneda stated.

There are no known fungicides for the treatment of Clubroot in canola. Very few seed companies have developed Clubroot resistant canola with more varieties in the process of being tested and marketed.

Beneda remarked that even with these resistant varieties the need to rotate them was crucial to prevent the Clubroot from becoming stronger.

The key to keeping the pathogen under control is cleaning equipment thoroughly and any  other machinery and vehicles that come in contact with the contaminated soil.

“Stay out of the fields when wet and muddy, go fishing instead” Beneda said.

The sanitation process begins with the location of where the cleaning takes place. It is recommended that units be cleaned and disinfected before leaving the field. A low traffic, grassy area is recommended to reduce chances of carrying soil off the field.

Begin with a rough cleaning using either a hand brush or wirescraper which will remove most of the loose or clinging soil from tires and equipment.

Next use a pressure washer set at two to three thousand psi on all areas where soil accumulates. Turbo nozzles are  more effective than regular nozzles for removing soil. This step along with step one should remove 99 percent of soil from equipment.

The final step is to disinfect all openers, tires, and wheels with a one percent solution of bleach or surface disinfectant of equal strength.

The recommendation for completing the disinfecting process is to use a three gallon backpack herbicide sprayer. The key to successfully disinfecting is to have areas sprayed remain wet for at least 15-20 minutes. This step is best done in the early morning or at night when evaporation will be slower.

The third step alone is not enough, the first two steps must be completed as well in order for disinfection to be effective in eliminating the pathogen.

While the cleaning process can be long in the undertaking, up to four hours or more for a 40 foot cultivator if all the steps are followed,  it is the best defense against the spread of the Clubroot pathogen.

For more information or to get the handouts from the presentation please contact Ron Beneda at the Cavalier County Extension Service, 701-256-2560