Editor’s note: This story was updated on Thursday, January 8th with additional information from the CFIA about the location of the case of verticillium wilt in canola.
The first North American case of a disease that has caused serious economic losses in Europe’s rapeseed crop has been found in a canola trial plot in Manitoba.
The Canadian Food Inspection Agency has confirmed the presence of Verticillium longisporum — a verticillium wilt pathogen — in a single plot at an undisclosed crop research location in the province. This is the first known case of the pathogen infecting an oilseed in the North America, although the soil-borne fungal disease has previously been found on other brassica plants, such as cauliflower, in the United States. It’s not the same pathogen that causes verticillium wilt in sunflowers, potatoes or alfalfa.
“We don’t know much about it because it is new to North America, however it is a common disease in northern Europe with their oilseed rapeseed/canola industry,” says Holly Derksen, plant pathologist with Manitoba Agriculture, Food and Rural Development, in the interview below. “There, where it’s a more widespread issue, they’ve seen yield losses of up to 50 percent.”
The original plant sample was submitted to Manitoba Agriculture’s diagnostic lab in September, with confirmation of the disease coming from a federal lab in Ottawa in October. Subsequent testing by CFIA officials at the undisclosed location yielded positive results for verticillium wilt in both the canola stubble and soil. Stakeholder groups, including grower organizations, were alerted to the findings in December. Derksen says more surveying will be done in spring to determine how widespread the pathogen might be.
Meanwhile, the CFIA says it is prohibiting the movement of host material and agricultural equipment used in the trial plot. The agency is also tracing where the seed used in the trials came from and developing surveillance plans around the plot to determine when the pest arrived and if it spread prior to detection.
Since it’s a soil-borne disease, Derksen says the approach to managing verticillium wilt in canola is similar to what’s recommended for clubroot disease. No fungicides are effective, and there is no known resistance in Brassica napus canola varieties. She notes Manitoba Agriculture is currently developing extension resources for producers.
While there could potentially be trade implications, Derksen says it’s difficult to say how significant the impact of verticillium wilt will be for canola growers.
“It’s hard to know at this point, because we don’t know how it got here.”
Listen to this interview for more information on this case of verticillium wilt in canola in Manitoba: