Illinois Researchers Say Higher Temperatures Spell Uncertainty for Sweet Corn

Nov 25, 2022

Few things say summer in America more than buttery corn on the cob, but as summer temperatures climb to unprecedented levels, the future of sweet corn may not be so sweet. New University of Illinois research shows sweet corn yields drop significantly with extreme heat during flowering, especially in rainfed fields in the Midwest.

Climate projections don’t just predict a handful of hot days going forward. The U.S. Global Change Research Program predicts 20 to 30 more days over 32 C [about 90 F] by mid-century across much of the U.S.

“The reality is that producing sweet corn, one of the most popular vegetable crops in the U.S., will be more difficult in the future. We need to develop new approaches and technologies to help crops adapt to climate change,” says Daljeet Dhaliwal, former graduate research assistant and lead author on the study published in Scientific Reports, in a recent release.

Dhaliwal worked with Marty Williams, USDA-ARS ecologist and affiliate professor in the Department of Crop Sciences at Illinois, to document yield response of sweet corn to growing season temperature and precipitation over a 27-year period. Williams obtained private data from sweet corn processors for 16,040 individual fields in Illinois, Minnesota, Washington, and Wisconsin, providing a much finer resolution than similar studies in field corn using county-level data.

“Our analysis reveals that small temperature changes have a greater influence on crop yield compared to small precipitation changes for both rainfed and irrigated fields in the Midwest and Northwest, but rainfed production shows greater sensitivities,” Williams says.

He adds that extreme temperatures during flowering can influence pollen viability, fertilization, kernel abortion, and other processes.

“If there’s a bad time for extreme heat, it’s during flowering. That’s especially true in a crop where ear quality is so important. With heat stress during flowering, you can have ears with fewer kernels or very misshapen kernels that look nothing like what the consumer is expecting,” Williams says.

This study used the concept of “extreme degree days” to capture the cumulative effect of temperatures above 30 C [86 F] during flowering on sweet corn yield. Degree days are normally calculated by taking the average of high and low temperatures over a given 24-hour period. To calculate extreme degree days, Dhaliwal summed degree days over 30 C.

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Video: How a Desire to Lead Brought This Wheat Breeder to Canada

Gurcharn Singh Brar is a wheat breeder whose path meandered from the breadbaskets of Punjab, India, to the sprawling fields of the Prairies. In a candid conversation, Brar shared insights into his journey, the challenges faced, and the undying passion that fuels his quest for better crops.

It all began with a childhood rooted in the wheat fields of Punjab, where agriculture isn’t just a livelihood but a way of life. His fascination with wheat and its potential led him to pursue a bachelor’s degree in agricultural sciences at Punjab Agricultural University. It was during this time that he encountered the spectre of rust diseases, particularly stripe rust, which plagued the region’s wheat crops. Determined to combat this menace, he set his sights on a journey that would take him across continents.

Venturing abroad for his graduate studies, he found himself in Saskatchewan at the Crop Development Centre (CDC), working under the mentorship of renowned researchers like Randy Kutcher and Pierre Hucl. Here, he delved deep into the world of wheat genetics, focusing on stripe rust resistance — a quest that would shape his academic pursuits for years to come.

After completing his master’s and Ph.D. in six and a half years, he embarked on a professional journey that would see him traverse academia and research. From brief stints as a research officer to landing his dream faculty position at the University of British Columbia’s Plant Science program, his career trajectory was marked by a strong drive to make a difference in the world of wheat.

Despite the allure of British Columbia’s unique agricultural landscape, he found himself wanting to return to the vast expanses of the Prairies, where wheat reigns supreme. He recently returned to the Prairies and is the new wheat breeder at the University of Alberta in Edmonton.

“The opportunity to lead an established wheat breeding program at the University of Alberta was a dream come true. With the necessary resources and infrastructure in place, I’m excited to drive innovation and develop high-yielding wheat varieties tailored to the unique conditions of northern Canada,” he says.

Brar, one of Seed World Canada‘s 2024 Next-Gen Leaders, has become known for identifying novel sources of resistance to priority diseases and his efforts in developing wheat germplasm with multiple disease-resistant traits.

In addition to his groundbreaking research, Brar is committed to mentoring the next generation of agricultural scientists.

“I believe in nurturing talent and empowering students to pursue their passions,” he says. “Watching my students grow and thrive in their research endeavours is hugely rewarding.”

As he looks ahead, Brar’s vision for the future of wheat breeding is clear: “My number one target is to develop high-yielding wheat varieties adapted to the northern climates of Canada. By focusing on early maturity and strong straw traits, we can maximize yield potential while ensuring resilience to environmental challenges.”

His decision to also join the Prairie Recommending Committee for Wheat, Rye, and Triticale (PGDC) executive as member-at-large came from a desire to play an even more important role in the world of Canadian cereals.