New Strains of Canola-Killing Clubroot Continue to Emerge in Western Canada

New strains of clubroot are continuing to emerge in fields in Western Canada, including six that are capable of killing canola plants that have been specifically bred to resist the disease, according to a study conducted by the University of Alberta.

Researchers sampled more than 250 fields in Alberta, Saskatchewan, and Manitoba in 2019 and 2020 identifying 25 unique clubroot pathotypes including seven new strains. Study lead Keisha Holman, Ph.D candidate in plant science, noted how these findings indicate how quickly pathotype shifts can occur.

Clubroot is caused by a parasite that infests soil with resting spores that can survive up to 20 years, and listed under Alberta’s Agricultural Pests Act, can cause canola losses ranging anywhere from 60-90 percent.

In 2019 alone, 23 pathotypes were documented showing the greatest diversity ever found in a single year. And of the five most common pathotypes identified in Alberta as of 2020, three overcome genetic resistance.

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