Clubroot pathogen shift: Management

In 2013, an Alberta field was identified where a clubroot resistant variety showed a high incidence of clubroot infection. Subsequent testing by the University of Alberta indicated that all current forms of resistance were not functional on the disease in this soil. This failure of resistance or its breakdown was determined to be due the increasing shift to a previously unidentified pathotype called 5x. Current clubroot resistance is still functional to the predominant pathotype 3 and the less dominant pathotypes 6, 5 and 8. But this 5x is able to overcome all forms of resistance on the market today.

Alberta Agriculture and Rural Development has taken the lead on managing this disease in Alberta. ARD will be coordinating an extensive survey to understand the extent of 5x’s distribution this fall. But as of now, recommendations to control clubroot remain the same:

—Use resistant varieties
—Scout for the disease
—Control brassica weeds
—Practice zero tillage
—Practice sanitation in high risk scenarios
—Use a four year rotation on infested soils

Read the full update from ARD: 2014 Sep 9 Clubroot pathogen update