It seems whenever a new disease or pest rears its head, the old wives tales and myths follow closely on its heels. Take, for example, the advent of clubroot being found in Alberta about 10 years ago. Never fear, said many in the more eastern parts of the prairies, our high pH western Canadian soils will provide protection. As of 2013, we can firmly and forever lay this belief to rest — clubroot has taken hold through much of Alberta, has been found in both Saskatchewan and Manitoba soils, and, most recently, was found in North Dakota. This soil borne disease may not fare as well in higher pH, but high pH will not stop the spread of this disease.
But, surely, something can be done? Unfortunately for all of us, this year was a “good” year for clubroot. Conditions were favourable for the disease’s growth, and, given the nature of this disease, it has spread further and further east and south from Alberta. Being the optimist that I am, I listened intently to a presentation given by Clinton Jurke, agronomy specialist with the Canola Council of Canada, at the Canola Discovery forum held last week in Winnipeg.
His presentation was decidedly somber when it came to tackling the clubroot question (There was also serious talk about blackleg. Click here to see my update on that). And that was BEFORE the announcement of a confirmed case in North Dakota. I followed up with Jurke after the conference to talk about what we can do about clubroot, how to dispel some of the myths around control and avoidance and how Manitoba especially is in a unique circumstance to learn from Alberta’s mistakes.
For those of you who won’t listen to the above interview (click here if you can’t see the Soundcloud player), here’s a short list of what will work for slowing the spread of clubroot (and yes, I recognize not all of these are as simple as they sound, but work with me here OK?):
- Stop moving soil! Tillage not only pushes soil about, it also increases the risk of wind and water erosion.
- Sanitize! Sanitizing equipment and vehicles that have been in known infested areas is a start. While it’s true that wildlife or livestock are walking about and there’s nothing we can do about that, equipment moves hundreds of pounds of soil in one go. Farmers purchasing equipment from out of province need to wash it before it leaves the home farm. End of discussion.
- Don’t buy seed, straw or hay from infested areas.
- Scout, scout and then scout some more. Clubroot affected plants die or ripen far earlier than healthy plants. It is no longer OK to assume that prematurely ripening plants are suffering from blackleg or sclerotinia. You MUST confirm what is killing the plants. Management for each disease is totally different — click here for tips on determining what’s killing your canola.
The Canola Council has a full page devoted to this disease. See that there.
Take note: yes, there are some varieties of canola with clubroot resistance, however, these lines only reduce the severity of infection, they do not stop the disease from developing. What’s more, resting spores of cludbroot can last for up to 20 years…just think about that for a minute. This is not a disease that we can simply spray away should it take hold in more areas. Avoidance measures, while cumbersome, are still the best bet in slowing or stopping spread of the disease.