First detected in canola in Manitoba in 2014, verticillium stripe is now found across the Prairies. According to 2024 disease surveys from the three Prairie provinces, this soil-borne pathogen was confirmed in 60 per cent of fields surveyed in Manitoba, 32 per cent of fields surveyed in Saskatchewan and six per cent of fields surveyed in Alberta.
In a 2024 Canola Council of Canada survey of 500 growers, verticillium stripe is also rising in the list of diseases, insects and weeds that pose the greatest economic risk to their canola production. Flea beetles, sclerotinia stem rot and herbicide-resistant weeds were the most common responses throughout 2024, 2022 and 2020. Only two per cent of growers put verticillium stripe as their “greatest economic risk” in 2020. That rose to six per cent in 2022 and 14 per cent in 2024. The Manitoba number last year was 36 per cent, putting it third in the latest survey (behind flea beetles and sclerotinia stem rot).
Distinguishing verticillium stripe from other canola diseases like blackleg or sclerotinia stem rot can take some practice. The ideal time to scout is at harvest when symptoms are most obvious. This article provides tips on accurately identifying verticillium stripe.
Management options for verticillium stripe are limited, but accurate identification is the first step to proper management. Some cultivars claim improved tolerance, but we don’t have genetic resistance. Verticillium microsclerotia are soil-borne, so steps to keep soil in place could provide some reduction in spread. Two- or three-year breaks between canola crops are good disease management in general, but verticillium microsclerotia can remain viable for many years.
Blackleg and sclerotinia stem rot, if those are the diseases present, are more manageable through genetic resistance, crop rotation and fungicides.
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