Verticillium Stripe: Why Soil pH and Disease Presence are Related

Jan 10, 2025

As canola farmers prepare for the spring planting season, attention turns to a potential issue creeping into the province — verticillium stripe. While this disease isn’t yet widespread in Alberta, its presence in neighbouring provinces and specific areas of southern Alberta is cause for concern.

One of the key factors influencing verticillium stripe is soil pH. Alberta’s soils tend to be more acidic, which has historically helped suppress the disease. In contrast, Manitoba and Saskatchewan, with their more alkaline soils (around a pH of 7 or higher), have seen significant outbreaks. Southern Alberta, particularly around Lethbridge, also has areas of higher soil pH, which could create conditions favourable for the disease.

“I think the pH difference explains why verticillium stripe is becoming a problem in Manitoba and why we’re starting to hear more about it in southern Alberta,” says Becky Wang, a recent graduate from the University of Alberta who has studied the disease extensively.

Like many plant diseases, verticillium stripe thrives in warm, dry conditions. Recent years have seen hotter, drier summers on the Prairies, contributing to outbreaks in affected regions.

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