Clubroot continues to be an issue throughout the province, but additional funding is helping researchers to tackle the issue. Dr. Ron Howard, plant pathologist and researcher with the Crop Diversification Centre South in Brooks, gave an update on clubroot at a recent seminar here.
Clubroot is a highly infectious plant disease that affects members of the Brassica family, which includes cabbage, broccoli, canola, mustard and cruciferous weeds. The organism that causes clubroot is a parasite that can only grow and reproduce in a living host. The parasite causes galls on the roots of infected plants. The galls are filled with millions of spores which help the infestation spread easily.
The disease causes yellowing and wilting of the host plants due to the root damage. Other symptoms include delayed flowering, areas with stunted plants or premature ripening. “This disease is capable of killing the plants at any stage from seedling to mature plant,” said Howard.
Yield losses caused by clubroot can be substantial. Clubroot was first detected in canola in 2003, and annual surveys for the disease have been carried out since. In that time, over 5,000 fields have been surveyed and the disease has been found in over 450 canola fields and in three vegetable fields.
Since 2003, clubroot has been confirmed in 17 counties and suspected in seven. Counties around the city of Edmonton, including Sturgeon, Parkland and Leduc have been the insurgent areas for clubroot. The dry spring conditions in 2009 lessened the impact of clubroot at the beginning of the year so no clubroot was found in southern Alberta. In central Alberta, 49 fields out of 224 surveyed fields were found to have clubroot. Late-summer rains and uneven crop growth likely caused more clubroot in some areas, said Howard.
He said producers should take care to rotate crops, and sanitize equipment that may carry clubroot spores. Researchers have been working to develop diagnostic methods for the disease, disease management methods and an understanding of pathogen biology.
There are over 25 scientists throughout Western Canada working on clubroot research. Agriculture Canada announced funding for a strategy on clubroot risk mitigation in 2009, which has helped co-ordinate and focus research in the area across Canada. Over $4 million has been allocated over four years to help develop the research. The research pillars include understanding the pathology of clubroot, breeding for disease resistance, and finding methods of disease management.
Preliminary research has shown that seed treatments may reduce the viability of clubroot spores on seen. Canola seed treatments seem to have an effect on seed-borne clubroot spores, said Howard.