Researchers study corn hybrids for drier regions

DuPont scientists look for ways to balance improved drought tolerance with better yields to suit Western Canadian fields

Manitoba corn acres increased more than 30 percent this year, rising to 325,000 from 250,000 in 2015.

The growth, based on Statistics Canada data, is a positive sign for the corn industry and proponents of the crop, who envision a future with millions of acres in Western Canada.

Many companies and plant scientists are developing corn hybrids suited for the Prairies’ short growing season, but others are working on what might be a larger obstacle to corn’s expansion: devising varieties that can withstand a month-long drought during the growing season.

Corn needs ample moisture, and many prairie producers, especially those who recall droughts from the late 1980s, remain skeptical that the crop will be successful in Western Canada.

“Where does (corn) do the best? In the parts of the States where they’ve got lots of water and heat,” said Doug Robertson, who farms near Carstairs, Alta.

“There’s a reason corn grows where it grows.”

Data from DuPont Pioneer shows that Robertson is correct. Yields plummet in dry years in the western fringes of the U.S. corn belt, such as the Dakotas and Nebraska.

Jeff Habben, a senior research manager for trait discovery with DuPont Pioneer, said yield losses from dry conditions in central and western North Dakota can be 60 to 80 bushels per acre.

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He said yield losses would likely be similar in Western Canada.

DuPont scientists are studying how to mitigate those losses so that corn can be grown in drier regions of North America.

“From a U.S. corn belt perspective, we’re interested in these fringe areas, particularly in the western fringe of the corn belt,” Habben said.

However, DuPont isn’t interested in years with extreme drought because such events are random. The company wants to develop corn varieties that can endure dry periods during critical times in the growing season.

Research at a DuPont farm near Sacramento, California, has demonstrated that irrigated corn with sufficient moisture yielded 200 bu. per acre. When DuPont scientists held back water to simulate dry conditions at flowering, they found that moderate drought caused yields to drop to 150 bu. acre.

Plots with more severe drought yielded 100 bu. per acre.

“We know the greatest (yield) losses in maize occurs during (the) flowering period,” Habben said.

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Knowing that dry conditions wreak the most damage at flowering is one thing, but addressing the issue is tricky because drought tolerance is a complex trait.

Jian-Kang Zhu, a Purdue University plant scientist, said it’s comparable to a balance scale, with drought tolerance on one side and plant development and yield on the other. Unfortunately, traits that improve drought tolerance tend to tip the scale, compromising growth and yield.

DuPont scientists are attempting to overcome that challenge and find solutions suitable for the northern Plains and Western Canada.

“We are actively trying to identify germplasm that grows in those areas,” Habben said.

“We have a maize breeder in the Dakotas that helps breed (corn) for those CRMs (comparative relative maturity) which are around 70 days.”

If DuPont does discover a drought tolerance trait for a warmer region such as Nebraska, the company could transfer the technology to shorter season varieties for Canada. However, Habben said such a process is challenging.

“We have a lot more germplasm from that central part of the corn belt to play with,” he said.

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“Making those crosses … into that germplasm up north, it can work but it’s not very straightforward.”