But with this popularity come risks. “With increasing production of canola every year in Western Canada, combined with changing weather patterns, conditions have and will become more conducive for the presence and adaptation of diseases on canola in many regions of the prairies,” said Coreen Franke, R&D Pathology Research, CPS.
Selecting the right variety is the best way to manage known issues or risks in a canola crop, or reduce the chance of resistance happening in the future. But with so many canola hybrids to choose from, it can be difficult to decide which the right one is.
When asked how he advises his customers on selecting canola varieties, Scott Anderson, Manager of Agronomic Services with CPS (Northwest Saskatchewan) said, “When I discuss choosing a canola variety with a grower I look at many things including, past crop rotation and herbicides used, any specific weed issues, and any disease concerns that the grower may have in their fields.”
The first considerations aid the agronomist in selecting the most appropriate system of canola for the grower to either address possible herbicide residue issues or weed spectrums present. The next step is to look at specific agronomic needs of the grower to best fit the hybrid.
“To be honest there are such strong genetics to choose from in every system on the market that I want a grower to look at the complete agronomic package when choosing a canola hybrid,” said Anderson. He also recommends that more growers should look at doing their own on-farm trials to find the best fits for their farms.
To Billy Brown and his father Dave Brown, selecting the right canola is an important decision they don’t take lightly. “We really look at the chemicals we can use, standability and how well it tables and holds together. And of course yield,” said Billy Brown of their selection process. Wind has been an issue in the past on their farm and he says it will be part of the decision in the future.
Brown says they have discovered how valuable working with an agronomist can be. He’s been working with Lyle Cowell, Manager, Agronomic Services, CPS for 20 years. “He really knows the area,” said Brown. “He provides insight and a great depth of knowledge about other trials in the area and anything new coming up.”
The Browns are committed to running regular crop trials on their 3,000-acre grain farm east of Tisdale, Sask. saying it allows them to stay current on the new varieties and see how they perform in their specific growing conditions. Brown gets out to see what is happening in other trials in the area and talks to local farmers too. “Some of the plot trials have experimental varieties, so it is good to see if they are doing what we need them to do here in our area.”
According to Coreen Franke, there are three crucial components for disease to develop in a crop: susceptible host plants, presence of the pathogen and favorable environmental conditions. “This is what plant pathologists refer to as the ‘disease triangle’, and all three components must be present in order for disease to develop,” said Franke.
While the weather is out of anyone’s control, the other two components of the disease triangle can be managed. “Breeders work to develop varieties with new and effective disease resistance genes in order to defend against evolving pathogens and eliminate susceptible hosts,” said Franke. The ongoing development of canola hybrids provides growers the tools to stay ahead of disease and resistance issues.
Disease is in Scott Anderson’s top three considerations when making variety decisions with his growers. Blackleg resistance, sclerotinia and clubroot are the major issues on the prairies. “Obviously if a grower is in or near an area where clubroot has been identified they should be looking at growing a variety with clubroot-resistant genes,” said Anderson.
Franke shared these disease management recommendations. “For blackleg, grow varieties that have received an R or MR rating in recent years. Older varieties may no longer be resistant to newer pathotypes. For clubroot, no variety is a ‘silver bullet’ for fields that have high levels of clubroot or where resistance in clubroot varieties has broken down. The only responsible option in that case is to not grow canola for at least 3 years.”
Both Franke and Anderson agree that proper crop rotation is the best defense against disease and can reduce the presence of pathogens. “Using the proper genetics in combination with proper crop rotation makes for a great disease management program,” said Anderson.
He added, “Something I think more growers should consider is utilizing multiple hybrids in their operation. This can help spread out harvest management, fungicide application timing and fit varieties to specific agronomic needs within specific fields. Also this helps a grower to evaluate performance of multiple hybrids for their specific farming operation.”
What diseases worry plant pathologist Coreen Franke? “Diseases like blackleg and clubroot are most threatening to future canola production because of their high potential for adaptation, especially in regions of intensive canola production. The main factors influencing this are tightened crop rotations and the practice of consecutively growing a single canola variety within that tightened rotation, especially if the variety doesn’t have the most current resistance genetics,” said Franke.
“In recent years, we have seen high blackleg disease severity in previously resistant varieties caused by evolving pathotypes (races), and in the case of clubroot, we are seeing quick adaptation of the pathogen to overcome the currently available resistance genetics, as evidenced by the recent identification of multiple new pathotypes that are virulent on clubroot varieties,” said Franke. This is partly caused by tightened crop rotations and the practice of consecutively growing a single canola variety within that tightened rotation.
The key to developing effective new disease-resistant varieties according to Franke is “knowing the enemy. An understanding of blackleg and clubroot host-pathogen interactions, race structure and distribution allows us to select the most effective resistance genes to incorporate into our varieties.”
Franke’s work with CPS includes collaboration with research organizations such as the University of Alberta, Agriculture and Agri-Food Canada (AAFC) and other industry partners that allow them access to the most up-to-date research findings and new resistance gene sources. “We believe that the best possible disease resistance should not simply be treated like an ‘add-on’ trait, but rather must be a core component built in to all Proven Seed varieties,” said Franke.
Sustainable canola production in western Canada will require proper stewardship and good disease management practices according to Franke. “Growers should always choose resistant varieties, and grow them within a responsible crop rotation in order to manage inoculum levels and preserve the resistance genetics available.”
“This is especially true for clubroot, a disease which has already proven a menacing capacity for adaptation. Canola varieties with multiple effective resistance genes are the first line of defense and can offer additional protection and durability, but crop rotation is central to long-term disease management,” added Franke.
Anderson wants growers to know that tools and resources are available to help growers make these decisions. Other issues an agronomist considers include weed spectrum and past crop rotations, as well as agronomic attributes of the variety such as lodging resistance and maturity.
“A variety with better lodging resistance generally makes an easier job of swathing and with the many acres that growers cover, anything that speeds up an operation is a good thing,” said Anderson. And if a grower is in an area with a shorter frost-free window, they would want to look at genetics with an earlier maturity. Selection charts and agronomists are there to help sort through the choices. “There are many options for canola growers on the market, and the best advice I can give is to consult with your retailer, taking all the agronomic considerations into account to help choose the best fit for your operation.”