Be proactive with clubroot management

Agronomists recommend farmers should have a clubroot management strategy well before the disease appears in their region.

Don't wait for dead patches

The Canola Council of Canada says early detection is important. A healthy looking plant on the surface could have galls on the roots, releasing billions of clubroot spores into the soil.

If found at an early stage, a disease management plan is much easier to implement, CCC states. Check spreading patches of stunted or dying plants, likely at the main and secondary field entrances, as well areas near grain bins, power lines, pipelines and oil sites. Clubroot spores can also be found in lower areas of the field where moisture accumulates.

Managing small patches of clubroot

Bruce Gossen, a plant pathologist with Agriculture and Agri-Food Canada, tells growers to pull out infected plants and burn the roots.

"Often the initial patch of dead and dying plants is the size of a big dining room table," Gossen says. "That is a size and situation where you can actually do something."

Mark out at least twice the size of the affected area in every direction using GPS, he says. Keep all traffic away from the area to prevent soil movement within the field and to other fields.

Gossen says applying lime to the soil can be effective, based on research conducted by the University of Alberta in collaboration with Alberta Agriculture.

"It is also enormously expensive, so you can't afford to do it on a large scale, but on a small patch, perhaps it makes economic sense," Gossen says.

Seeding the patch to a perennial grass is a good alternative because its extensive root system stimulates clubroot spores and serves to drive down their numbers in the soil. Weed control will be required until soil surveys indicate spore levels are low or zero. After that occurs, Gossen says growers should only seed clubroot-resistant cultivars.

Getting the message out

Saskatchewan plant disease specialist Barb Ziesman says a recently released clubroot map illustrates an estimation of provincial disease spread. Visible clubroot symptoms were confirmed in 43 commercial canola fields in 14 rural municipalities across northern and central Saskatchewan.

"It is important to remember that just because clubroot has not been detected in an RM to date, that does not mean it is not there,” Ziesman says. "Based on the map, the area with increased clubroot risk includes the entire northern agricultural region."

SaskCanola Chair Lane Stockbrugger says the clubroot map is a useful tool and should lead to more extensive field scouting by growers this year. Prevention also remains a key priority.

Clubroot risks are high this year across the Prairies. Be on full alert for scouting, disease prevention and management. Tweet this

"A three-year crop rotation is ideal," Stockbrugger says. "Look at seeding clubroot resistant varieties and try to minimize soil movement with the field and definitely between fields."

Bottom line

Clubroot is present in all three Prairie provinces. Experts recommend producers go on the offense and take steps such as implementing three-year crop rotations and seeding perennial grasses. The disease is easier to manage in the early stages, so check out suspicious plants and even do random checks.

Article by: Neil Billinger