A new canola variety resistant to multiple strains of clubroot will hit the market in time for spring seeding.
But the new variety from Crop Production Services will only be available in limited quantities and a clubroot expert says growers can’t expect it to be “a saviour.”
CPS Canada says the variety, Proven Seed PV 580 GC, has shown “high levels of resistance to the current predominant clubroot pathotypes, as well as some of the newly discovered highly virulent clubroot pathotypes referred to as 5X.”
“We’re really excited about this new variety because it’s the first multigenic clubroot-resistant variety that will be available to growers,” said Ryan McCann, director of seed for CPS Canada.
“This is another tool that will help them combat the spread of clubroot by having another gene available in rotation with their other crops.”
This variety is “a good start,” said Canola Council of Canada agronomist Dan Orchard.
“There would be fields and areas identified where this could be deployed quite reasonably, but because of all the different strains out there, we certainly can’t make a blanket statement that this is going to combat clubroot in everybody’s fields,” he said.
“It’s definitely a step in the right direction. It’s promising for the industry that there’s more resistance out there and more to come.”
The variety, which also has good blackleg resistance, will be available in areas where clubroot is already a problem in Alberta, primarily in the north-central area around Edmonton.
“We have good supply, but we certainly don’t have ample supply of this variety,” said McCann. “It’s more part of a resistance package or rotation that the grower would use in a clubroot area.”
This “multigenic” resistance — meaning it has two genes with resistance — is important because, in most fields, there isn’t just one strain of clubroot, said Orchard.
“We’re finding these populations that aren’t just single strain within fields,” he said. “The more strains that we have resistance to and the more diversity we have in how the resistance reacts, the better chance we have to keep it in check.”
But with so many unclassified strains of clubroot present in the Canadian Prairies, this new variety won’t protect against them all.
“It’s just the tip of the iceberg with the discovery of these strains that haven’t been classified yet,” said Orchard, adding there are “many variations of 5X.”
“I wouldn’t want to call it a saviour for all the strains out there that we haven’t classified. We don’t know that yet, because these strains are popping up as we speak.”
Because clubroot-resistant varieties aren’t 100 per cent effective against unclassified strains, scouting is still “the No. 1 most important” thing producers can do to protect themselves from clubroot, said Orchard.
“The quicker and earlier you can discover clubroot on your farm, the more management tools you do have in place. You can micromanage those areas provided that you know where they are.”
But once clubroot becomes established in the field, moving to a longer rotation and deploying resistance are really the only management tools producers have, he added.
“There are some techniques that are available, but not once the field becomes heavily infested,” said Orchard. “Then our only tool seems to be extending your rotation significantly with a resistant variety.”
McCann sees this new variety as part of a “stewardship approach” in areas where clubroot is already a problem. And that means following proper rotations.
“We don’t want growers using this as an excuse to grow canola back to back,” said McCann, who recommends “a responsible canola rotation.”
“We always want to practise a good rotation first, because that’s your best combat against the disease, and this is the best option in those rotations.”
So far, canola growers have been “pretty lucky” in having new varieties with better clubroot resistance come to market, “but the next steps will be a little more difficult.”
“We’ve picked the low-hanging fruit already, and now it’s time to get up to the fruit that’s not so easy to pick,” McCann said. “It’s such a complex organism that we’re really just at the tip of the iceberg. We’re getting there, but we’ve certainly got a long road ahead.”
But the new variety is a sign the journey has begun, said Orchard.
“It’s encouraging to know that new genetics are being explored and deployed for use in these new varieties.”