Six down and 10 to go.
If producers are going to hit the Canola Council of Canada’s goal of achieving 52 bushels per acre, they’re going to have to change their management approach, says the organization’s agronomy director.
But it can be done, said Clint Jurke.
“When we launched this 52-bushel plan four years ago, we were averaging about 35 bushels at that time. So we’ve gained about six bushels in four years on average,” Jurke said at a Powering Your Profits event here.
“But we need to get another 10 bushels an acre to make sure we have enough canola to keep up with the demands that the economists are forecasting.”
Jurke offered attendees an agronomic blueprint for achieving that level of yield — some straightforward and others more tricky.
“Step 1 is encouraging the industry to target 60 bushels when you’re making your fertilizer decisions,” said Jurke. “There are producers who will be targeting much higher rates than that, but if we can get the average of the country looking at a target of yield higher than 52 bushels, then certainly we can help drive to that 52-bushel mark.”
Step 2 is reducing seed mortality — currently averaging 50 per cent — through increased seeding rates or steps that improve emergence.
“If we can get 75 per cent to harvested plants, that’s going to help drive our yield.”
Step 3 is cutting harvest loss, which can be as much as five bushels an acre.
“That’s pretty high,” he said. “We go through all that effort to grow the crop, and to lose it during one of the last operations is a real shame.”
The goal should be a loss of less than two per cent of yield — that is, one bushel in a 50-bushel crop.
Things get trickier on the disease front, but the potential gains are significant.
Sclerotinia is the largest yield-robbing disease annually, and this year, it cost growers an estimated five per cent of yield.
And if weather conditions are right, an infection is almost inevitable if there are spores in the soil. However, blackleg and clubroot can — and should — be managed to improve yield, said Jurke, noting the former can cost Alberta farmers $200 million in a single year.
“Blackleg does cost us yield, and the yield loss does cost us a lot of money,” he said.
Blackleg infections are rated on a severity index from one (little yield loss) to five (near total loss).
“There’s almost a 20 per cent yield loss with each of those ratings,” he said. “If you are finding blackleg in a field and it’s in that two or three range, you’re losing yield, and therefore you’re not going to be as profitable with growing your crop.”
Blackleg levels dropped significantly after resistant varieties arrived in the mid-’90s, but the disease has been overcoming resistance, pushing infection levels to 20 per cent in the last four years (though that has since dropped to less than 10 per cent).
Each resistant variety has a different resistance gene — and that needs to match up with the strain in your fields, said Jurke.
“We found that farmers were buying a variety that had an R-rating on it, growing it out in the field, and suddenly there was a big blackleg problem. It’s because the pathogen has changed, and that resistance gene that the majority of us were using in our canola varieties was no longer functional.”
Start by determining the infection level in your field.
Swathing is typically the best time of year to measure that (pull plants, cut them open, and examine the inside of the stem).
“Only when you know if blackleg is a problem can you make the right decisions to actually control it,” he said.
And if present, “you need to rotate — rotate crops, rotate resistance.”
“We have been recommending for blackleg a three-year break out of canola,” he said.
“We can’t rely on our current crop rotation in order to minimize the amount of blackleg. The fact that we’re seeing so much canola out there is likely the reason we’re having some issues with blackleg now.”
Rotating resistance is now easier, thanks to a new labelling system adopted by some seed companies identifying the type of resistance in each bag of seed.
“If you’re buying a variety, it’s still going to have that R-rating on it. But many varieties will, as well, have this resistance grouping.”
But the pathogen present in the field needs to be identified through genetic testing at a seed lab.
“There are now three different testing labs across the Prairies where you can send infected canola samples and they will tell you specifically what blackleg races are present,” said Jurke.
“And when you know what races are present, you can figure out what resistance is actually going to be effective against those races.”
Look at using a fungicide for fields that have seen blackleg in the past and is likely to reoccur.
“In those types of situations, using a fungicide is going to provide some value.”
Resistance is also a huge issue in clubroot — in the Edmonton area, more than 200 fields have had their resistance fail.
“This pathogen has a lot of ability to defeat our control strategies,” said Jurke. “It’s resistance that we’re most worried about.”
Scientists have now identified 17 different pathotypes, some of which had defeated the early resistance that came to market. But they believe there are upwards of 36 different pathotypes in Canada.
“This is not good news for us as an industry,” he said. “Somehow, we need to prevent that initial infection from happening in the first place because, eventually, you’re going to grow a variety that’s susceptible to a given pathotype.”
Growers need to focus on sanitation to reduce its spread.
“This pathogen travels wherever soil travels,” said Jurke. “Soil that moves naturally — either by wind or water erosion — is a risk, but it’s largely our movement of farm machinery that’s responsible for the movement of this disease.”
A Swedish study found 84 billion spores on a single pair of dirty rubber boots from an infected field.
“There’s enough spores to cause disease over a 40-acre patch,” said Jurke. “That’s just footwear. How much is moved on farm machinery?”
Sanitation is a good way of reducing that, he said.
“The less soil that can move, the better we’re going to contain this particular disease.”
Rotation is also key — a one-year break doesn’t reduce spore levels significantly, but a two-year one does.
“As more data comes out, we may change our recommendations, but at this point in time, it looks like that two-year break is our best recommendation.”
And doing the reverse — tight rotations with a susceptible variety — “is a recipe for disaster,” he said.
Last year, there were 24 clubroot-resistant varieties on the market. That nearly doubled to 42 this year, he added.
“Start using a resistant variety now,” said Jurke.
Add it all up — enough fertilizer, improved emergence, lower harvest losses, and better disease management — and an average yield of 52 bushels an acre is achievable, he said.
“It’s a big challenge, but I think we’ll get somewhere close to it,” he said.