Dr. Dilantha Fernando, a University of Manitoba researcher, is leading a group of researchers who intend to pinpoint avirulence genes in blackleg found in farmers’ fields. Researchers with Agriculture and Agri-Food Canada and Alberta Innovates – Technology Futures are also involved.
Researchers will also study how the fungus adapts to different canola cultivars and how agronomy affects blackleg populations. They’re currently looking for farmers in southern Alberta to allow them to collect samples once or twice a year during the four-year study.
Researchers will share data with individual growers, but results will be published in anonymous or aggregated forms. People collecting field samples will avoid introducing clubroot and other pests by following biosecurity practices such as wearing plastic booties or rubber boots, disinfecting between fields and avoiding driving in fields.
Clint Jurke, agronomy specialist with the Canola Council of Canada, says this project will show how much of a threat blackleg is in the long term.
“We’ve got a lot of different resistance that we’re using in varieties right now. But the big question is how good is this resistance going to be,” says Jurke, who specializes in disease management. “How long is it going to last? Is it going to be durable into the future?”
Once researchers know how the blackleg pathogen adapts and canola resistance breaks down, “it’ll be up to the seed companies to determine what resistance genes are going to be the most appropriate in the long term,” says Jurke.
Blackleg has “genetic ammunition” to be big problem
Autumn Barnes, agronomy specialist with the Canola Council in southern Alberta, says a 2012 survey didn’t show a lot of blackleg, or severe blackleg, in her region. But she says the sample size was small.
Despite that, Barnes cautions people to look for the disease.
“You always see a little bit every year and I certainly have seen some loaded-up fields. But in general if we see a high load of blackleg the grower goes to a longer rotation,” says Barnes.
The Canola Council of Canada recommends scouting for blackleg before swathing. Once plants are swathed, other fungus and bacteria feed on plant tissue, making it harder to identify blackleg. The Council also notes blackleg symptoms usually show around the plant’s crown. Lesions further up the stem might be caused by another disease.
So far the industry has stayed ahead of the disease, Jurke says, but they’ve seen cases of resistant canola cultivars failing in the field as the pathogen evolves. Blackleg is still considered a minor disease, Jurke says, but it’s an ongoing trade issue between China and Canada.
“And second, blackleg does have the potential to become a very big threat if we don’t play our cards correctly,” Jurke adds. “Out of all the diseases we deal with it has the most genetic ammunition in order to become a big problem for us once again.”
Interested Alberta canola producers south of Highway 1, from Medicine Hat west, can contact Dr. Aliaa El-mezawy of Alberta Innovates – Technology Futures at 780-632-8225. Dr. El-mezawy can also be contacted by email.
For details on the blackleg research,visit FarmingSmarter.com.