One thing that is becoming very clear at the agronomy meetings this fall is that, when it comes to clubroot, the maps are changing and not in a good way.
Bruce Gossen, plant pathologist with Agriculture and Agri-Food Canada (AAFC), gave a presentation on clubroot at the Canola Industry Days held at Saskatoon recently. He says that while we may be surprised by this fall’s findings, we shouldn’t be. What is playing out is the trend we have been seeing for some time.
“The situation is changed in terms of (our) perspective but in reality the situation has not changed enormously,” Gossen says. (story continues after audio)
In Manitoba, 15 more fields have been identified with clubroot. Saskatchewan has 37 new fields with clubroot symptoms, and in Alberta they are also seeing expansion of the pest into new areas.
“We know from lot’s of experience, lot’s of actual sad experience, that the disease can create problems in areas that are dry and have very alkaline pH,” he says.
That’s the take-home message from all of this new data is that growers need to be scouting their own fields or paying someone to do it for them
Saskatchewan spearheaded a huge survey over the summer, but surveys can’t replace old fashion scouting, Gossen says. “Most of the fields that were identified, were identified not by random surveys but by growers going into their own fields and having a look at patches of dead and dying plants. That’s the take-home message from all of this new data is that growers need to be scouting their own fields or paying someone to do it for them.”
What is more troubling with the findings in Alberta is that the pathogens are changing, which means the resistant varieties are beginning to get out-flanked. “The new pathotypes are a big problem. The breeding efforts are ongoing; all the seed companies are involved in developing new cultivars. The problem is that there are so many new pathotypes that developing resistance that covers all the new pathotypes is a huge challenge that we are not close to meeting yet.”
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