First identified in Manitoba in 2014, Verticillium longisporum has spread across the Prairies like wildfire. This soil-borne fungal pathogen causes verticillium stripe in canola, which is a stem striping disease that causes canola plants to ripen early, leading to lodging and yield loss.
As soil temperatures warm in the spring, the microsclerotia of verticillium in the soil seek growing canola roots, then enter the plant and move in the xylem to the plant stem where the true damage happens.
Impact of Verticillium Stripe
The impact of damage typically isn’t seen until harvest or shortly after, but hot, dry conditions help to express the plant damage earlier on. Canola stems will show half stem senescence, then become extremely fragile and shred to reveal the microsclerotia growing beneath the stem wall.
In 2025, 73% of fields surveyed through the Manitoba Provincial Canola Disease Survey were identified to have verticillium stripe present. Saskatchewan continues to find more fields every year with the disease, and Alberta is now also having lab-confirmed samples pop up across the province.
Identification and Management
Core Challenges in Verticillium Stripe Management
- Misidentification risk: Can be confused with blackleg or sclerotinia, complicating field identification.
- Limited effectiveness of traditional tactics: Crop rotation, weed management and scouting have not kept verticillium stripe at bay.
- Significant yield losses observed: Many growers report heavy losses and a lack of successful management strategies.
- Lack of clear recommendations: No definitive, science-backed control methods currently available.
Research and Breeding Efforts
Current Research and Breeding Actions
- Breeding for tolerance: Plant breeders are screening canola hybrids for potential resistance to verticillium stripe.
- Unknown mechanisms: The resistance mechanism within hybrids is still not identified.
- Lack of a check standard: The industry lacks a resistant and susceptible check for hybrid screening.
- Noted susceptibility differences: Some hybrids show better tolerance under infection, which provides clues for future breeding.
- Hope in existing germplasm: There is optimism that Canadian canola already harbors some tolerance in its background genetics.
Verticillium stripe is widespread and appears here to stay, so learn how to properly identify it in the field against other canola diseases. Industry collaboration will be key to better understand and develop management practices against this disease.
FAQ
What is verticillium stripe and why is it a concern for canola growers?
Verticillium stripe is a stem striping disease in canola caused by the soil-borne fungal pathogen Verticillium longisporum. It causes plants to ripen early, leads to lodging and results in yield loss, making it a significant concern for growers across the Canadian Prairies.
How does verticillium stripe infect canola plants?
In the spring, as soil temperatures warm, the microsclerotia of verticillium in the soil seek canola roots to infect. The disease then enters the plant and moves through the xylem to the stem, where it causes most of the damage.
What are the main symptoms of verticillium stripe in canola?
Symptoms include half stem senescence and stems that become extremely fragile and shred, revealing microsclerotia growing beneath the stem wall. The damage is usually visible at harvest or shortly after, but hot dry conditions can make symptoms appear earlier.
Are current management practices effective against verticillium stripe?
Current integrated management tactics such as crop rotation, weed management and scouting have not been effective at keeping verticillium stripe controlled. There are no clear management recommendations at this time.
What research is being done to address verticillium stripe in canola?
Researchers and plant breeders are working to screen canola hybrids for tolerance to verticillium stripe. While the mechanism for resistance is still unknown and there is no industry standard for screening, differences in susceptibility among hybrids have been observed. There is hope that some background tolerance exists within Canadian canola germplasm.
