In a big change to nation’s corn, you might soon see shorter stalks

As a teenager in a small Iowa town in the 1980s, I would join dozens of kids around this time of summer on crews at a Cargill research plot where we helped scientists control pollination of corn hybrids under development.

We’d start work very early to finish before the heat of the day. By 8 a.m., we’d all be covered in dew, sweat, dirt and pollen.

The last summer I did it, we were only about halfway through the season when a big windstorm toppled the field and ended our work. We kids went back to school with a little less money than we expected and a lesson in the risks of farming.

For decades, crop scientists improved corn yields by making plants taller. Reaching 10 feet or more by harvest time, these plants produced bigger ears with more grain. Now, economics and harsh weather are steering farmers and seed companies in the other direction.

Shorter corn plants — topping out around 7 feet — are better able to withstand thunderstorms and windstorms.

After a derecho devastated Iowa in August 2020, photos of toppled silos, buildings and trees stunned most of us. But the photos that intrigued farmers and crop scientists showed fields of short-stature corn still standing after the storm packed winds of 120 mph and caused $11 billion in damage.

Shorter plants also make it easier for farmers to add fertilizer to fields late in the growing season. They can’t navigate tractors and sprayers through taller plants after midsummer.

Scientists and farmers are finding the shorter plants are producing ears with nearly as much, and often the same, amount of corn as the tall plants do. And since it’s possible to fit more of the shorter plants into a field, per-acreage yields actually rise.

“This is a Corn Belt-wide thing,” said Jeff Coulter of the University of Minnesota Extension. “The major seed companies are working diligently on it.”

For 12 years, Stine Seed, Iowa’s independent seed giant, has been selling shorter-stature hybrids to farmers. They now account for half of the company’s corn business by volume, Myron Stine, the company’s president, told me last week.

This summer, Bayer — the multinational giant that owns Dekalb and Channel seeds, which has about 60 Minnesota farmers involved in its early commercialization effort — joined Stine. Other seed companies are following suit.

“If you think about all the innovations over the last three to five decades — switching from in-breds to hybrids, bringing in traits to protect against pests like rootworm, herbicide tolerance, breeding advances — farmers figured out the most they could get from them,” said Denise Bouvrette, a scientist at Bayer Crop Science. “This is the next step-change.”

The impact of this change might be even greater than math and plant chemistry suggest because farming is under the twin pressures of demographics and changing priorities for land use.

An innovation that will allow farmers to grow significantly more corn, perhaps 15% to 20% more, out of an acreage at first glance suggests they will use it for more overall production. It can also mean farmers will need less land to produce the same amount of corn they do right now.

That second alternative is important when so many farmers are aging out of the business, and there’s a prospect more rural land will shift in coming years to energy production.

Science magazine, in an article about short-stature corn last fall, noted scientists in the 1950s and 1960s created smaller varieties of wheat and rice that allowed them to produce more grain without collapsing. Bouvrette noted the idea has been around for many decades. She said Bayer began working about 15 years ago to make its highest-yielding breeds shorter.

“Below the ear, you have this inherent stability. And the tassel isn’t quite the sail whipping around in the wind. So the plant doesn’t fall over nearly as easily,” she said.

At Stine, shorter plants came about as a by-product of a quest to produce higher-yielding corn. Company founder Harry Stine in much of the ‘80s and ‘90s focused on breeding corn that would grow closer together. He wanted to push the per-acre population of corn plants higher.

“He would create all these brand new inbred lines and make new hybrid combinations out of them. And he put them in plots at higher populations intentionally to find the genetics that liked populations and stood,” said Myron Stine, Harry’s son. “We really don’t care about the short-stature part. That wasn’t the objective. That was just something that came out of it.”

Minnesota farms tend to have around 30,000 to 35,000 corn plants per acre. Stine said his company’s hybrids perform even at 43,000 plants per acre.

The math on short-stature corn won’t work out for every farmer, of course. Planting crops densely requires some changes in equipment, which poses costs to farmers. And more plants require more water and fertilizer, which also means more costs. Some farmers find it’s difficult to harvest the short-stature plants when they are on hills because the ear is too low to the ground for a combine to snag.

Weather is a perennial risk, though, and might lead farmers to give the shorter plants a try.