High yields prove today’s seeds tolerate drought far better than farmers ever expected
By ANNE FITZGERALD, REGISTER AGRIBUSINESS WRITER

Bob Henderson feared heavy crop losses because of this year’s drought. He thought he would be harvesting insurance checks, rather than filling bins with grain.

In late July, an Iowa State University Extension specialist estimated that Henderson’s corn would yield on average 125 bushels per acre on his land east of Albia. Henderson thought that was optimistic, but this fall, he has harvested a big — and much needed — surprise: Corn yields on his best ground have topped 200 bushels per acre — a target considered unimaginable 10 or 20 years ago, particularly given the drought.

“I was kind of hoping all my corn on all of my acres would average 125 to 140 (bushels per acre), and I think I’m going to be over that,” the farmer said Thursday morning as he maneuvered his Deere & Co. combine through a 90-acre field, harvesting six rows at a time. “It’s going to make the bills easier to pay, I’ll tell you that.”

Across the Corn Belt, farmers are finding that last year’s exceptional yields were no fluke. As they finish the fall harvest, many are reporting high-yielding corn and soybean crops — even in areas where excessive heat and prolonged dryness last summer diminished yield expectations.

Crop experts credit farm management practices, timely rains and luck for the production of what are expected to be the second-largest U.S. corn and soybean crops ever. For instance, farmers do far less tillage, which helps preserve soil moisture.

But growers, agronomists and market analysts also point to crop genetic improvements, particularly increased drought tolerance, as a key to this year’s unexpected bounty.

“There is no doubt that we have to thank the corn breeders for getting the kind of corn yields we have gotten this year, despite the drought,” said Palle Pedersen, an Iowa State University Extension agronomist.

Kan Wang, a plant molecular biologist at Iowa State in Ames, agreed that genetic improvements are the main contributor to increased yields. But she also said that corn’s full potential is much higher than today’s highest yields. One of the biggest barriers is environmental stress.

“The potential is there, but we are hampered by all of these factors we have no way to control,” said Wang, whose research includes the study of abiotic stresses, such as drought, on crops.

This fall, many farmers in eastern and southeastern Iowa, areas hit hard by drought last summer, have harvested dismal yields. But many also have seen wide variation, with some reporting corn yields of more than 150 bushels per acre. In Illinois, the epicenter of this year’s drought, the harvest has yielded similar reports. In addition, 2005 soybean yields surged past previous projections throughout the Midwest, especially in Iowa, where farmers have harvested their largest soybean crop ever, according to the U.S. Department of Agriculture.

Mark Carlton is an Iowa State Extension field crop specialist whose territory covers eight southeastern Iowa counties.

“I was totally surprised at the yields that were coming in, both corn and soybeans,” Carlton said. “I think corn hybrids are just bred to stand more stress than they were 15, 20 years ago.”

He had predicted that Henderson could expect to harvest 125 bushels per acre. But that was before early August, when rain fell on the farmer’s fields — about six inches over 10 days.

“That corn turned green after it rained,” Henderson said. “I don’t think I’d ever seen that — corn turning green after it had turned brown.”

Like many growers, Henderson credits genetic improvements with the crop’s performance.

“I think the genetics are the main thing,” he said. “If we were planting the same genetics we planted years ago, we probably wouldn’t have anything.”

Crop seed behemoths like Pioneer Hi-Bred International Inc. and Monsanto Co. are touting this year’s surprising crop yields, as the companies gear up for the 2006 seed sales season.

Both companies have improved corn yields through conventional plant breeding programs, selecting higher-yielding hybrids that withstand dry conditions and other stresses. Both companies also have in their product pipelines crops designed with biotechnology to resist drought. Pioneer, which has a slight lead over Monsanto, expects to bring its first engineered drought-tolerant hybrids to market within four to five years. Monsanto hopes to commercialize its own engineered drought-resistant corn hybrids after 2010.

Pioneer’s two top research priorities for seed corn are to increase yields and to improve hybrids’ drought tolerance, said Joe Keaschall, corn research director for the Des Moines-based company. Those priorities overlap, he said. Both have global ramifications, as the world’s population and global demand for food grow and as water becomes a more strategic resource.

“This is a major problem, and it’s growing in importance as water supplies become limited around the world and in the United States,” said Patrick Schnable, associate director of Iowa State’s Plant Sciences Institute.

Increasingly variable weather patterns add to the importance of drought tolerance, Schnable said, adding that Iowa crop farmers face increased water-related problems.

Yield improvements take money, effort and expertise, and a trait as complex as drought tolerance takes a lot of resources, he said.

“Improving plants is not a short-term activity,” he said. “It’s a long-term investment.”

But the potential payoff is enormous, particularly for drought-resistant traits, in part because drought is such a pervasive problem around the world.

By one estimate, farmers globally lose more than $8 billion to drought every year.

“It’s becoming a bigger issue,” both in the United States and in developing nations, Pioneer’s Keaschall said. “Water is the most limiting factor on yield. Zero water, zero yield.”

Drought tolerance is “a challenging trait,” he said, because damage can occur under various conditions and at different points in crop development.

“There’s probably different genes that are responsible for drought at different times of year,” he said.

Stan Dotson, a plant geneticist who is head of biotech-based crop yield research for Monsanto, oversees the St. Louis company’s drought-tolerance team. Various facets of corn development are affected by drought, including the plant’s growth rate, its photosynthetic ability, pollination and kernel filling, he said.

Some engineered traits in seeds already being sold commercially, such as Monsanto’s rootworm-resistant seed corn, can help corn plants withstand dry conditions by making them less susceptible to other environmental stresses, Dotson said.

He also said that engineered drought tolerance likely will involve multiple genes, rather than a single gene. In addition, some genetic discoveries pointing to drought tolerance can be applied to various crops, he said.

That’s good news for soybeans, which are highly sensitive to environmental stresses, said Pedersen, a soybean specialist at Iowa State. He hopes that two years of high yields won’t make farmers and the research community complacent.

“We have a lot of competition,” Pedersen said, “and we cannot sit back and be satisfied just because there is a record crop this year in Iowa.”