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Genetics taking corn to new heights

On a mid-July morning, Matt Splitter walked deep into his dryland corn crop on the central Kansas plains and plucked an ear from the stalk.
It’s not a perfect cob. Not all the yellow kernels develop, Splitter said, pointing to the ear tip back. He kicked at the ground between the rows.
“There is no moisture there at all,” he said.
Rain has come sparingly. The field near Sterling, he estimated, has received between 4 to 5 inches of moisture since he planted it in late April.
It might be a tough year for dryland corn. However, Splitter said, a decade ago his family would never have thought about sowing acreage to such a risky, water-intensive crop in an area where rainfall can be variable.
Corn still is still a risky crop compared to wheat and sorghum, he said. But Splitter and other Midwest farmers are better equipped to take that gamble.
The reason? Better farming practices and precision tools. And, don’t forget, improved genetics.
“None of these would have developed,” said Splitter of the corn varieties available just a decade ago. “There wouldn’t be an ear, nothing. There wouldn’t have been enough moisture, there wouldn’t have been enough vigor, to shoot anything.”
Central Kansas farmer Matt Splitter looks at an ear of corn in his field near Sterling in Rice County. Splitter said the field has only received 4 to 5 inches of rain this year. The crop is holding on, however, thanks to management and better genetics. Splitter began planting corn on his farm shortly after Monsanto released its DroughtGard corn in 2012. Corn is now part of a rotation that includes wheat, sorghum and soybeans. (Journal photo by Amy Bickel.)
The genetic race
If scientists are right, the world is growing warmer and the weather patterns more variable. According to a 2012 study by U.S. Department of Agriculture economists, by 2030, the fluctuating climate could cost Corn Belt farmers between $1.1 to $4.1 billion.
Companies like Dupont Pioneer, Monsanto and Syngenta are working to develop corn genetics that not only have a rising yield curve, but also can withstand drought, cold, heat and a declining aquifer in the High Plains region. Crops of the future also will need to have better ability to thrive on marginal ground, as the amount of arable land shrinks and the world population approaches 9 billion.
Drought tolerance is important, but so are genetics that can withstand these irregular climates, said Patrick Schnable, director of Iowa State University’s Plant Sciences Institute.
“The challenge we face is weather patterns are becoming more variable,” said Schnable, who specializes in genetics. “Our corn growing systems are adapting, but the concern is the amount of weather variation we will experience in the future is greater than our current crops can handle.”
The challenge of making crops resistant to variable weather has recently become an active topic among researchers, he said.
But breeding a highly productive crop with the ability to adapt to inconsistent and stressful conditions isn’t a simple process. Essentially, Schnable said, the genes that control traits and the genes that confer stability of those traits across environments are different.
Drought has taken a toll on ears of corn in Matt Splitter’s cornfield near Sterling, Kansas. Splitter said if it weren’t for improved genetics, he wouldn’t have any crop this year. He began planting corn in 2012 with the release of better, drought-resistant varieties, which have taken out some of the risk of growing water-intense corn in harsher climates. (Journal photo by Amy Bickel.)
The complexity of water-stressed corn
However, genetic advancements are making a difference, especially on the High Plains.
As corn acres increase outside of the Corn Belt region, drought tolerance has become a focus for seed companies. These non-traditional corn-growing areas often don’t have the soil moisture holding capacity or the rainfall that is typical of big corn states like Iowa or Illinois, Schnable said.
“The drought tolerance of corn has been improved dramatically,” he said. “There are limits, of course. If you don’t have water, you can’t grow corn, but we are better off now than we were in previous years.”
Splitter, a fifth-generation farmer, added corn to the rotation when he came back to the farm in 2012, planting Monsanto’s newly released DroughtGard variety.
“We’ve gone to a rotation that has corn as one of the main rotations in it,” Splitter said. “The genetics in the corn currently make it feasible.”
Monsanto combined a drought-tolerant biotech trait with a drought-selected germplasm. Others in the race, including Pioneer and Syngenta, developed hybrids through traditional breeding.
Syngenta invests $1.3 billion globally on crop protection and seed research and development annually, said Duane Martin, the commercial traits lead for Syngenta.
Syngenta began to develop water-optimized corn hybrids in the early 2000s. The first commercial Agrisure Artesian hybrids were launched by Syngenta in 2012 with the goal to maximize yield when it rains and increase yield when it doesn’t. Agrisure Artesian technology is also stacked with insect control and herbicide resistance traits.
Martin said the company tested Artesian traits across the corn belt and found these hybrids yielded about 12 percent better than hybrids without the trait when under typical drought conditions.
Meanwhile, breeders at DuPont Pioneer also have chased corn’s drought challenge aggressively for two decades. The company introduced Optimum AQUAmax hybrids beginning in 2011. A 2015 study across 10,000 farms showed these hybrids were, on average, 6.5 percent higher yielding under water-limited conditions and 1.9 percent higher yielding under favorable growing conditions.
Farmers want two things: Consistency and predictability, Martin said. That means drought-tolerant hybrids must yield well in good conditions but protect against severe yield loss when stressed.
“We didn’t want a drought-tolerant hybrid to cause a grower to sacrifice yield potential when the conditions were good,” he said. “We wanted to deliver hybrids that yield as well as any elite hybrid, but also offer downside risk assurance when conditions are difficult.”
Water stress in corn is complex, Martin said.
“You don’t solve a something like drought stress with a single gene that acts at a specific time,” he said. “The corn plant has to get through water stress when it occurs.”
Scientists are analyzing the corn genome to identify multiple means for the plant to use water more efficiently, considering both severity of drought and timing, he said. For instance, highly productive areas might not have a drought that lasts for months but instead suffers from gaps in rainfall that come at important times in the crop’s growth cycle.
Genetic research keys in on how to blunt the stress during key times like flowering and grain fill, said Calvin Treat, the global corn and soybean technology lead for Monsanto.
“It’s about testing the hybrids you are developing in the right season so you can get the stress tolerance and see how it will react,” Treat said. “We know enough about the genetics in the different families of corn that we can make some pretty good predictions that are in the genes of a certain corn plant.”
A gene’s performance is eventually validated in the field under managed stress environments, including in plots in semi-arid regions like southeastern Colorado for Syngenta and Gothenburg, Nebraska for Monsanto.
Researchers simulate different levels of drought in an attempt to test the genes identified. It might mean taking them to the edge of death by withholding water, then recharging the soil profile to determine what will happen then, Martin said.
“You do the lab portion that identifies the gene, but you don’t know if it accomplished what you set out to do unless it is in real-world conditions,” Martin said.
Corn’s expansion
Corn’s genetic refinements are evident across the United States, Schnable said. Better bred varieties allow corn acres to expand in the western states and areas that that might not have had corn before.
Colorado farmers are expected to harvest 1.46 million acres of corn this year, compared to 950,000 acres in 1990, according to the National Agricultural Statistics Service. In Kansas, farmers planted 5.4 million acres this year, compared to 1.6 million 30 years ago. In Nebraska, corn acres have expanded by 2 million for the same period.
Schnable said the increased acres are a conversation coming up in classes. Dennis McNinch, the father of one of Schnable’s students, is among the High Plains farmers expanding into corn.
McNinch hails from Ness County in west-central Kansas, where irrigation is nonexistent and rainfall averages about 21 inches a year.
He began increasing his corn acreage on his farm starting in 1995, moving to a wheat, corn and fallow rotation.

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