Canada: Weather called biggest ‘yield robber’ this year

The biggest “yield robber” of canola on the Prairies turned out to be the weather, says an authority on the subject.

Although periodic heavy rainfall compounded the emergence of diseases and predatory insects, disagreeable weather caused considerable damage all on its own.

Both the western and eastern Prairies received extreme weather that weakened canola production in 2024, said Curtis Rempel, vice-president of crop production and innovation with the Canola Council of Canada.

Researchers sometimes divide the “western” from the “eastern” Prairies at a point around the Saskatchewan-Manitoba border. This is intended to delineate the brown and dark brown soil zones of most of southern Saskatchewan from the black and grey soil zones of Manitoba, Rempel said.

The east experienced an “incredibly wet spring,” he said, delaying seeding and driving a need to catch up throughout the growing season.

The rain didn’t end with spring. A 200 millimetre rainfall event — also in the east — occurred in September in the middle of canola harvest.

“(That was) maybe not so much a yield robber at that time. It was a quality robber,” said Rempel.

The western half of the Prairies had — in some regions — the opposite problems.

“I’m generalizing a bit, but (the west had) a more normative spring but then had heat during flowering; a 14-day period when the canola was starting to flower where we had some high temperatures on parts of the Prairies and then along with it, drought,” said Rempel.

The extreme heat intensified yield loss.

“Canola pollen is pretty sensitive to heat during flowering, and when you have prolonged heat over 30 C, you start seeing yield drop-off.

“So, too much water in spring in parts of the Prairies and then heat during flowering.”

These weren’t the only tough conditions canola producers dealt with, said Rempel. Prolonged high winds in the spring delayed seeding and spraying in some areas, allowing weeds to get the jump on canola planting, and that’s particularly bad news for a small-seeded crop such as canola.

“There’s that famous Neil Harker, Bob Blackshaw study that said four weeds emerging ahead of or at the same time of the crop does more damage than 200 weeds emerging 10 days after the crop,” Rempel said.

Harker is a current researcher with Agriculture Canada and Blackshaw is a former researcher with the federal department.

“That early season weed control when the crop is emerging, that’s what we call the critical period. It’s very difficult for growers to time that, and we ended up having some later applications of herbicides.”

On the disease front, the biggest yield robbers were blackleg, verticillium stripe and — to a lesser extent — sclerotinia, said Rempel.

The council — at the time of this writing — did not yet have data on the extent of damage these diseases created, but survey maps were expected to be presented for discussion at the Western Forum on Pest Management in Regina Nov. 5-7 with the possibility of broad distribution in December.

Being a relatively new disease, verticillium stripe was a major topic among growers, breeders and agronomists this past year and continues to be a research focus. It appeared to be particularly destructive in Manitoba, said Rempel.

“I think there would be agronomists who’d agree and farmers who would agree they’d be losing 10 bushels an acre or maybe more to verticillium. It can be a big, big yield robber.”

Not surprisingly, blackleg hit the worst in regions with a very wet spring, he said.

“We had really good conditions for inoculum production, which comes from spores on stubble, and you require rainfall and mist to disseminate those spores. We had that in large parts of the Prairies in spring.”

Insect issues were patchy, he said. Early season cutworms were found at seeding in parts of Alberta and Saskatchewan. There were pockets of flea beetles in the Alberta Peace Country, eastern Manitoba and the Swan River Valley, where some fields were re-seeded due to spring flea beetle damage.

“High populations were also observed in fall at or near harvest in these areas, but high fall populations do not contribute to yield or quality loss. Nor have high populations of flea beetles in fall been a good predictor of where they appear the following spring,” wrote Rempel in a follow-up email.

Bertha armyworms were also found in the Peace Country in locations such as Fairview, Falher and Nampa, where populations were above economic threshold in some cases.

It was also discovered west of Yorkton, Sask., and in south-central Manitoba. However, the latter populations were not above the economic threshold.

Lygus bugs were found in southern Alberta around Lethbridge and again in the Peace Country. Eastern and southwestern Manitoba had fields where lygus populations were above the economic threshold, said Rempel.

Other insects included grasshoppers in southern Alberta and southern Saskatchewan.

So what does all this mean for next year’s growing season? Obviously, farmers can’t control the weather, but there are ways to climate-proof their fields to an extent, said Rempel. One is to consider the maturities of a number of varieties.

“Maybe growing some early-maturing varieties to try to beat the heat and then planting them early as well. You may protect some of the yield potential that you have on your farm.”

If blackleg is a problem, now is the time to look at what’s happening in your field and whether your canola varieties are meeting resistance expectations, said Rempel.

“There’s enough opportunity then to think about deploying different resistance genes because there’s a lot of companies that have quite an offering of resistance genes, or for what we call major blackleg resistance.”

Ultimately, every individual farmer needs to evaluate their own management strategies when preparing for the coming growing season, he said.

“I can’t stress that enough. You have to evaluate it for your own farm and then your own fields as you’re working together with your agronomist and input supplier.”

Codie Nagy, a canola, durum, red lentil and chickpea producer from Ogema, Sask., said he saw an approximately 40 per cent yield reduction in his canola this year and — like Rempel — he considers weather the main culprit.

“June was really cold and wet, so the crop was quite slow growing, and by the time July rolled around, it was probably 10 days behind,” said Nagy.

“And then, on about the 10th of July, when the canola was full flower, is when the heat set in and it stopped raining, so we suffered from pod blast. The cold in June that slowed the crop down kind of made the heat in July a little more damaging than it normally would have been.”

Although his canola crop wasn’t disastrous, there’s no doubt these weather events took the wind out of his crop’s sails.

“It goes from canola being arguably the most profitable crop on our farm to the least profitable one. It was quite a big swing on potential revenue loss. Luckily, we still had a decent canola crop; it’s just we would have probably had a record one if that heat didn’t set in.”

Nagy said he saw more blackleg than normal, but he doesn’t consider it a yield robber.

“At harvest time you could notice more grade off stalks than there normally would be. There was enough where my seven-year-old son was counting them at every supper time to see how many he could find.”

Nagy tries to weather-proof his canola as much as possible, but the options are limited, he said.

“When it comes to weather like that, it’s pretty hard to manage. Essentially, you just try to get your crop off to the best start as possible, so make sure you have the proper amount of nutrients there and you do a good job of seeding and you give it a chance to establish well. And hopefully there’s no stress when that heat rolls around.”

Nagy’s game plan for next year will likely be the same as always, he said. He can’t seed too early because of frost risk and flea beetle issues. In his area, seeding from May 10-20 seems to hit the sweet spot.

“That usually has it flowering before the heat sets in in July, and then it’s late enough where the flea beetles don’t seem to bother us as bad as in spring.”

For almost 30 years of expertise in the agri markets, UkrAgroConsult has accumulated an extensive database, which became the basis of the platform AgriSupp.

It is a multi-functional online platform with market intelligence for grains and oilseeds that enables to get access to daily operational information on the Black Sea & Danube markets, analytical reports, historical data.

You are welcome to get a 7-day free demo access!!!

Tags: Production, Prairies, damage, loss, yield robber, harvest, canola, weather, Canada