Verticillium Wilt of Canola Detected in Manitoba

Manitoba Agriculture, Food and Rural Development (MAFRD) has identified Verticillium wilt (Verticillium longisporum) in canola (Brassica napus) in Manitoba. This is the first time this disease has been detected in Canada.
 
The disease was visually identified by the MAFRD Crop Diagnostic Centre on a canola sample submitted because patches of wilted canola were observed in a field. The pathogen culture was sent to the National Fungal Identification Service in Ottawa for molecular identification, which confirmed it as Verticillium longisporum 
 
MAFRD is working with the Canadian Food Inspection Agency (CFIA) to implement biosecurity risk mitigation measures where this pest was detected. The CFIA will conduct further surveying in spring 2015 to determine the spread of the pathogen.
 
The current risk of spreading this pathogen is extremely low, as the ground is frozen and necessary precautions are being taken like stubble management and restricting the movement of farm equipment.
 
More information will be made available leading up to the spring for the canola industry, building on additional information provided through surveying efforts.
 

Facts about Verticillium Wilt in Canola

Verticillium wilt is the most common disease found in canola in Sweden and is common throughout much of northern Europe.  Brassica crops like mustard, rutabaga, cabbage, cauliflower and broccoli crops can also be affected by this species of Verticillium. This is not the same species that causes Verticillium wilt in sunflower and potatoes, which is common throughout Manitoba.
 
Symptoms of Verticillium wilt in canola include chlorosis of lateral branches or leaves (often one-sided), early senescence and stunting. At later stages, the epidermal layer of the stem may peel back to reveal black microsclerotia.
 
Find out more on Verticillium wilt in canola.
 

Management of Verticillium Wilt in Canola

Verticillium longisporum is a soil-borne pathogen that can survive in the soil for 10 to 15 years, so biosecurity practices similar to those recommended for clubroot can help also prevent the spread of this disease.
 
The amount of spores in the soil declines over time. In Europe, where Verticillium wilt has been a long-term issue, the recommended crop management practice is to leave three years between canola crops.
 
Fungicides are not effective against this disease and host resistance in canola is not available at this time.
 

Symptoms of Verticillium Wilt in Canola at Harvest

Black microsclerotia can be seen just below the surface epidermal layer in this photo of an affected plant:
 
 

For more information

Contact MAFRD's Crop Industry Branch at 204-745-5660.