Basic clubroot control better than no control at all

Producers are told they don’t have to be perfectionists when it comes to knocking mud and dirt off of their equipment

BRANDON — There’s lots of wisdom from Alberta about how to manage clubroot.

For Manitobans, the best advice is probably this motto: “It’s OK if you can’t do everything, but it’s not OK to do nothing.”

That was a message taken to Manitoba Ag Days both by central Alberta farmer John Guelly and Canola Council of Canada agronomist Dan Orchard.

“I wish I hadn’t waited until I saw clubroot galls on my field to start using a resistant variety,” said Guelly, who was hit by the disease in 2013.

“By the time I used it my spore load had already risen up.”

Using a resistant variety and growing canola only one year in three are key elements of clubroot control, but one brief physical action with machinery can have a huge impact on spore movement: knocking dirt and mud off the tractors, seeders and combines.

Some farmers become intimidated by recommendations that they spend hours sanitizing machinery, but Guelly and Orchard said five to 10 minutes of basic mud and dirt removal can eliminate 90 to 95 percent of the spores hitching a ride on the machine and greatly reduce the danger of the disease being transferred to other fields.

That’s where the wisdom of doing what you can even if you can’t do everything you should comes in. There’s no reason to despair if perfection isn’t possible.

“You want to keep your spore numbers as low as possible,” said Orchard.

Recent research has shown that a three-year rotation with canola grown one in three years manages to reduce soil spore load by 90 to 95 percent. That’s because immature spores die off quickly if not given a host to infest.

So having most spores die off through rotation, plus simply cleaning off machinery before leaving fields, provides easy and powerful control.

Farmers can also switch between different resistant varieties and different herbicide tolerance systems. That way weeds, such as stinkweed, shepherd’s purse and volunteer canola, can be better controlled.

Scouting can also identify little hot spots in fields. Hand-picking diseased plants is an effective way of stopping patches quickly spreading, and pulling out and destroying weeds pulls billions of spores out of the soil.

Pioneer Hi-Bred agronomist Michael Weir said Manitoba farmers are lucky because they can still get ahead of clubroot.

“We’re at a good point here where if we start implementing these plans early we can manage this disease effectively,” he said, noting very low spore loads in infested fields today.

Farmers should be scouting now, growing resistant varieties and assuming they might have clubroot near them. “Tailgate tours” that he did in rural Manitoba last summer helped explain to Manitoba farmers what to look for. Some went home and looked.

“Sure enough, they had found clubroot in their fields as well,” said Weir.

“This is a good thing: guys getting out in the field and scouting.”

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