Clubroot has now climbed into the Peace region — and its recent discovery will change the way canola farmers operate in the area’s southeastern corner.
Alberta Canola announced Aug. 23 that one case of the serious soil-borne disease was found in a canola crop in Big Lakes County, which surrounds much of Lesser Slave Lake.
Dan Orchard, an agronomist with the Canola Council of Canada who represents northern Alberta, said the case in the Peace isn’t widespread.
“It’s really quite isolated,” he said, noting Big Lakes neighbours counties to the south and east where the disease has already been detected.
“It’s fortunate that the grower and the agronomist he’s working with were so diligent at catching it and are now dealing with it. It’s been a blessing.”
Up until the discovery of the disease, which spreads via soil, Peace region farmers hardly had to worry about clubroot. This meant some growers had short rotation cycles for canola.
Now, farmers with the disease in their communities are going to have to plant clubroot-resistant varieties in intervals of at least three years — which is what their southern neighbours in the Edmonton region have been doing for a little over a decade, Orchard said.
“Resistant varieties are going to be a huge help, but they’ll have to be rotated properly,” he said.
“In some situations, a two- or three-year break isn’t even long enough.”
Other ways producers can reduce the spread of clubroot include minimizing soil movement between fields via equipment, cleaning machinery more thoroughly, reducing tillage, scouting fields more frequently, and avoiding purchases of hay or straw from contaminated regions.
Greg Sears, chair of Alberta Canola Producers Commission, agreed that longer rotation cycles are the best way to combat the disease. When it’s not canola’s turn, planting pulses or non-host crops, like oats, could be good options, he said.
“Clubroot was eventually going to happen,” Sears said. “It’s not a magical land in the Peace and it wasn’t going to be immune forever, as much as we would love to think it’s an area separated by green space. The reality is, it’s not.”
Clubroot infects the crop’s roots and causes irregular club-like galls that restrict the flow of water and nutrients to leaves, stems and pods.
Symptoms include wilting, stunted growth, yellowing, premature ripening and shrivelled seed. Though producers shouldn’t assume anything, clubroot can be diagnosed by closely examining the roots, according to Alberta Agriculture on its website.
“You want to be diligent, pulling out plants at the entrance and inspecting the root to be well ahead of it,” Orchard said.
The disease can also be detrimental for yields.
If a field is almost entirely infected, yield losses can reach 50 percent, Alberta Agriculture stated. If infestations range from 10 to 20 percent of the field, losses can range from five to 10 percent.
Orchard said clubroot is generally found in patches and not throughout an entire field, which means the affect on yields is fairly minimal.
“Showing below-ground symptoms early is the ultimate find,” he said.
“Often there isn’t total devastation because people are finding it earlier, which is a huge help.”
He said the current situation in the Peace region is an opportunity for agronomists and producers to get ahead of the disease and control it, unlike the Edmonton-area outbreak in 2003.
“I don’t see it taking over like it has in central Alberta,” he said. “I see a bright side to finding it early so it’s managed properly.”