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ISU Developing High Yielding Heat-Resistant Corn Variety

01 August 2011

US - The last few week's sizzling temperatures and high humidity may be taking their toll on this year's corn crop as well as people, researchers and crop experts say.

The "could be" scenario is a complex one.

"The weather this week is exactly what our research is meant to address," Alan Myers, an Iowa State University (ISU) research specialist, said this week. "Anyone outside today anywhere near a corn field can, I think, realize the importance of this line of research - not only ours but the national effort underway by the U.S. Department of Agriculture (USDA)."

"All predictions of our future climate suggest this week will be normal in the years to come," Myers added. "It's especially bad at certain times when the crop grain-filling is underway and temperatures are as we're presently experiencing."

According to the Le Mars Daily Sentinel, Myers, a professor in the university's Department of Biochemistry, Biophysics, and Molecular Biology, is among members of a research team backed by a $5 million USDA grant studying possible development of a corn variety that can maintain high corn yields for corn producers despite high temperatures.

Myers said the team is "taking a novel approach" to theoretical testing of each gene in the corn genome focusing on the metabolism of the kernel where it is believed heat effects are greatest.

This is being combined with additional studies related to plant drought tolerance, photosynthetic efficiency and other approaches to heat tolerance.

Pioneer Hi-Bred, which opened a research operation in Orange City earlier this year, is among collaborative partners on the project to determine the heat-tolerant yield traits.

"At the present time we are relying on existing literature to demonstrate the connection between heat and yield in order to focus our research goals," Myers said. "Because this is a federal project, once actual results are obtained in the form of new traits, these traits will be public knowledge and made available for incorporation into production lines."

Myers said the study is part of a response within the scientific community to challenges issued by the National Research Council in an earlier report, "New Biology for the 21st Century: Ensuring the United States Lead the Coming Revolution."

A dozen or more scientific source references point to the fall-off in corn yields at "abnormally high" temperatures at a time in the corn plant's life cycle in which temperature is very important, he said. This drop has been evident even in fields with good irrigation, if temperatures are too high at the wrong time, he added.

"Our main goal is to determine how to keep yields up [with corn varieties] that can withstand the extreme temperatures," Myers said. "Temperatures like those we've been experiencing will clearly reduce yields. If this high heat becomes normal, as is predicted in the next two decades, the increases in yield we've become used to are unsustainable."

Myers said current research shows yield decreases of up to 25 per cent when the sustained heat temperatures rise from 90 to 95 degrees during the plant's kernel-placing period.

Yield losses of up to 40 per cent are projected in the world's tropical and sub-tropical corn production areas by the end of the 21st century, he added.

"The development of new production lines that keep our high yields in conditions like those we've been seeing is necessary to maintain the profitability that comes from the production we're accustomed to in Iowa," Myers said. "While the heat trend is of course a prediction, the trends are consistent, and the USDA sees this as a significant danger."

Myers agrees that the possible crop yield losses can have an environmental and economic impact globally as well as nationally.

"It is the long-term goal of any agronomist, biotechnology specialist or molecular biologist such as myself to be a member of a research team that can is successful in developing traits that allow good corn yields in high temperature environments," he said.

"While this is obviously important for our Iowa corn producers and corn production in our state, our research also takes into consideration what lower yields can do in subsistence farming operations in developing countries such as South American and sub-Saharan Africa," he said.

In these countries, temperatures are already extreme and likely to get worse, Myers said.

"Even minor improvement in crop performance in high heat in these countries can mean the difference in life or death," he said.

Myers said the team is especially proud to be part of a proactive approach looking to the future.

"This current USDA agricultural research can be seen I believe as outcome-driven in the near term," he said. "To someday be able to apply fundamental science for outcomes benefiting our society 50 years from now is a satisfying approach for us."

TheCropSite News Desk

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