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Gobind Farms owner Satnam Deenshaw looks over his blackberry crops that were recently damaged by the heat wave that Vancouver Island and other parts of British Columbia experienced.CHAD HIPOLITO/The Globe and Mail

Extreme heat and dry conditions have devastated crops across Canada, scorching and stunting key agricultural products as farmers brace for the potential of more unfavourable weather and try to minimize their losses.

With large swaths of the country under heat warnings over the past month, crops that prefer moderate temperatures and moisture levels are producing abysmal yields or are threatening to do so. Plants are wilting and, in some cases, dying. Irrigation reservoirs are getting low and farmers are rationing water. In the northwest United States, workers harvested blueberries in the middle of the night to beat the daytime heat; one farmworker died in an area where temperatures rose above 40 C.

On British Columbia’s Vancouver Island, family-farm owner Satnam Dheenshaw said the recent record-setting heat burned his entire early crop of raspberries and about half of his blackberry crop, amounting to at least $30,000 in losses. “The plants looked as if someone took a blowtorch to them,” said Mr. Dheenshaw, of Gobind Farms in the village of Saanichton. “All the leaves were crisp, like in the fall.” He has never seen anything like it in his more than four decades on the farm.

Though it’s too early to gauge the impact on this season’s yields for some commodity crops, the hot, dry conditions forecast in certain production areas is causing volatility in financial markets. Spring wheat futures are trading at a historically high premium, and the canola market is “just going bananas,” as one analyst put it.

More warm weather and more frequent extreme weather events, including heat waves, are among the most consistently predicted outcomes of climate change. This certainly applies to Canada, which is projected to warm about twice as much as the global average for a range of climate scenarios, according to a comprehensive federal report published in 2019. So, while weather is naturally variable, the kind of heat wave that scorched Mr. Dheenshaw’s berries will occur with increasing frequency and intensity in the future.

“This is something that all of us should be concerned about,” said Steve Miller, an environmental economist at the University of Colorado Boulder and co-author of a recent study on the connection between heat waves, climate change and economic output. “These big, punctuated events can tip the crops over the edge.” The study, published in the Journal of the European Economic Association, predicts damages in agriculture due to prolonged high temperatures may be upward of 10 times greater than previously thought.

The recent heat wave that moved eastward across Canada was compounded by an unseasonably dry spring and periods of drought in some growing regions. In Alberta, the most recent provincial crop condition rating – which includes crops such as spring wheat, canola, chickpeas and barley – declined 13 percentage points from the previous report, with 68 per cent of crops rated in “good to excellent” condition compared with the five-year average of 76 per cent.

The Saskatchewan crop report for July 6 to July 12, the newest one available, said the majority of crops were deemed to be in poor to good condition. “The prolonged period of heat, coupled with the extremely dry conditions of the topsoil, has caused crops to be short, thin and impulsively advancing in many regions of the province due to the stress,” the report said. “Without a significant rainfall, many crops throughout the province will have their yields and quality severely impacted.”

The most recent Agriculture and Agri-Food Canada report on weather-related risks to Canadian agricultural production warned the most significant threat to crops last month was the “intensifying and expanding drought across Western Canada and extreme heat across British Columbia and Alberta.” The report noted that drought in Ontario and Quebec continued to be a concern, and Manitoba experienced the largest moisture deficits so far this year.

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Young red potato plants from the Peak of the Market research site have set tubers, showing potential for growth. Cooler temperatures and much needed rain will help these tubers bulk into marketable size.Dr. Tracy Shinners-Carnelley/Handout

Tracy Shinners-Carnelley, vice-president of research and quality with Peak of the Market, a not-for-profit grower co-op and the sole distributor of fresh-market potatoes grown in Manitoba, said conditions are so dire in some parts of the province that irrigation reservoirs are drying up. By early July, she said, potato farmers like to see what’s known as rows clothes – when a canopy of ground cover emerges to obscure the individual rows of potato plants. The lush, green leaves shade the soil, moderating temperatures and reducing evaporation to allow the underground tubers to thrive.

“We haven’t seen the rows clothes,” Dr. Shinners-Carnelley said. “Farmers realize this is a serious situation, but we’re still being optimistic at this point.” The yield and quality of this year’s potato season depends heavily on the weather over the next couple of weeks; farmers are hoping for lower temperatures and some rainfall.

Curtis Rempel, vice-president of crop production and innovation with the Canola Council of Canada, said it’s too soon to tell how the heat and dry conditions will affect this season’s crop of the oilseed. Grown primarily in northeastern B.C., Alberta, Saskatchewan and Manitoba, canola is considered a resilient plant with multiple built-in defence mechanisms; it can, for example, release water from its leaves to cool itself down.

But like any other crop, canola has its limits. Once temperatures get about 30 C, the viability of the pollen starts dropping, causing yields to decline. Another factor is nighttime temperatures; if the plant is given even a brief reprieve from hot weather, it can recalibrate and produce pollen more reliably.

Mr. Rempel said volatility in the canola market is in large part due to concerns about the potential for continued high temperatures and low rainfall in key growing regions. “People are saying, ‘Okay, there’s more hot, dry weather in the forecast and we’re in the last phase of flowering, so without rain in the forecast, what does that do?” he said. “It looks like more stress for the crop.”

Chuck Penner, owner of LeftField Commodity Research in Winnipeg, said what’s going on in the wheat market is “really a story about what’s happening in the Canadian Prairies and the northern U.S., where they grow red spring wheat, which is the hard, high-protein wheat that’s used to make your bread nice and fluffy and rise well.” Prices are continuing to move higher, especially for spring wheat futures on the Minneapolis Grain Exchange, which is the principal market for hard red spring wheat.

Put simply, the spring wheat crop is in bad shape, he said. In general, the crops are shorter than usual – two-thirds their normal size, reaching about knee-height instead of hip-height. They also have fewer heads, and the heads have fewer seeds and more of reduced quality. “We’re still trying to figure out the implications for yield,” Mr. Penner said. “With no rain to speak of in the forecast, its just going to keep getting worse and worse.”

In Mr. Dheenshaw’s Saanichton, B.C., the 14-day forecast shows temperatures mostly within the historical range, but he’s hoping for cool weather. He said about 80 per cent of his blueberries look fine at the moment, but blueberries show signs of heat stress a little later than some other berries. He doesn’t know how much of his blueberry crop will shrivel up.

Mr. Dheenshaw said he’s also struggling to find workers. He and other farmers are rushing to get new berries off their plants to fulfill orders, and to get burned berries off them to reduce contamination and prevent moulding. “What can you do?” he said, pausing to gather himself. “You have to pay your bills. You have to pay your employees. … Your input costs are out there. Everything … got turned upside down because of the weather.”

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