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Sweet Corn Sweltering In Summer Heat Spells Uncertainty For Corn Lovers

By Lauren Quinn

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.

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.

For rainfed regions, every extreme degree day during flowering led to an additional yield loss of 2%. For irrigated systems, yield loss was less severe; just 0.5% per degree day over 30 C.

But more than one day at 40 C [104 F] could drop yield by 20%. This result was based on season-long hourly temperature data, not degree days.

The pattern suggests irrigation could ameliorate the effects of extreme heat, but climate scenarios also warn water could be in short supply in the future. The authors note that if sweet corn yield and quality continues to decline due to climate extremes, planting times or production areas may need to shift to avoid the hottest temperatures.

In the meantime, Williams says there’s only so much breeders can do to build in heat tolerance.

“The question becomes how do we develop sweet corn to become more resilient to increasing environmental stressors? To what extent can you do that by managing the crop versus improving the crop itself? These are hard questions.

“The thing we really need to do to prevent worse outcomes is to minimize further climate change. But we're in a period where we're going have to deal with what's already set in motion,” Williams says. “Our trajectory is already set for the next several decades.”

Source : illinois.edu

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Moving Ag Research Forward Through Collaboration

Video: Moving Ag Research Forward Through Collaboration



BY: Ashley Robinson

It may seem that public and private researchers have different goals when it comes to agricultural research. However, their different strategies can work in tandem to drive agricultural research forward. Public research may focus more on high-risk and applied research with federal or outside funding, while private sector researchers focus more on research application.

“For me, the sweet spot for public private sector research is when we identify problems and collaborate and can use that diverse perspective to address the different aspects of the challenge. Public sector researchers can work on basic science high risk solutions as tools and technologies are developed. They then can work with their private sector partners who prototype solutions,” Mitch Tuinstra, professor of plant breeding and genetics in Purdue University’s Department of Agronomy, said during the Jan. 10 episode of Seed Speaks.

Public researchers they have the flexibility to be more curiosity driven in their work and do discovery research. This is complimentary to private research, which focuses on delivering a product, explained Jed Christianson, canola product design lead for Bayer CropScience, explained during the episode.

“As a seed developer, we worry about things like new crop diseases emerging. Having strong public sector research where people can look into how a disease lifecycle cycle works, how widespread is it and what damage it causes really helps inform our product development strategies,” he added.

It’s not always easy though to develop these partnerships. For Christianson, it’s simple to call up a colleague at Bayer and start working on a research project. Working with someone outside of his company requires approvals from more people and potential contracts.

“Partnerships take time, and you always need to be careful when you're establishing those contracts. For discoveries made within the agreement, there need to be clear mechanisms for sharing credits and guidelines for anything brought into the research to be used in ways that both parties are comfortable with,” Christianson said.

Kamil Witek, group leader of 2Blades, a non-profit that works with public and private ag researchers, pointed out there can be limitations and challenges to these partnerships. While private researchers are driven by being able to make profits and stay ahead of competitors, public researchers may be focused on information sharing and making it accessible to all.

“The way we deal with this, we work in this unique dual market model. Where on one hand we work with business collaborators, with companies to deliver value to perform projects for them. And at the same time, we return the rights to our discoveries to the IP to use for the public good in developing countries,” Witek said during the episode.

At the end of the day, the focus for all researchers is to drive agricultural research forward through combining the knowledge, skills and specializations of the whole innovation chain, Witek added.

“If there's a win in it for me, and there's a win in it for my private sector colleagues in my case, because I'm on the public side, it’s very likely to succeed, because there's something in it for all of us and everyone's motivated to move forward,” Tuinstra said.