Des Moines Register
12-10-06
300 bushels per acre corn yield no longer a pie-in-sky goal
t could be possible thanks to germplasm and biotechnology
By ANNE FITZGERALD
REGISTER AGRIBUSINESS WRITER
A generation ago, Iowa farmers would not have imagined harvesting 200 bushels
of corn per acre. Now it is commonplace, and crop experts see 300 bushel-peracre yields on the horizon.
How soon corn growers will cross that threshold is a subject of contention, but
the jump in yields cannot happen soon enough. Demand for Iowa's leading crop
is soaring, and new ethanol production is driving much of the demand. Pressure
is growing for U.S. farmers to raise more grain.
Adding acreage by shifting soybean acres to corn production - widely anticipated
in 2007 - will help farmers meet the demand, but boosting corn yields also will be
key. Plant breeders, seed corn suppliers, agronomists, farmers and others must
collaborate to hit the 300-bushel-per-acre goal, industry experts say.
"Is it pie in the sky? No. Will it happen next year? No. But yields are going up
every year, and the rate of yield increase is going up," said Rodney Williamson,
director of research and development at the Iowa Corn Growers Association in
Johnston.
Since 2002, U.S. corn yields on average have topped 140 bushels per acre nearly double 1965's average and up one-third from 1995. This year, national
yields are expected to average 151.2 bushels per acre. In Iowa, the largest cornproducing state, corn yields are expected to average 163 bushels per acre this
year, with total production topping 2 billion bushels.
Farmers increasingly report corn yielding more than 200 bushels per acre in Iowa
and surrounding states. Many producers and other crop experts credit improved
corn genetics, as well as agronomic practices.
Farmers, for instance, have narrowed corn row width and increased the number
of seeds planted per acre. Fifty years ago, a plant population of 15,000 per acre
was common; today, most farmers plant more than twice as much corn per acre.
Major seed companies cite both germplasm - the genetic material contained in
crop seeds - and biotechnology for yield increases.
"In our company, it's really about our genetic research. It's about understanding
our germplasm at the DNA and the gene level," said Ian Grant, a Ph.D. plant
breeder and geneticist who is vice president for maize product development at
Des Moines' Pioneer Hi-Bred International Inc.
DuPont-owned Pioneer, the No. 1 seed corn supplier in North America, has
invested heavily in increasing yield potential of the corn hybrids the company
sells.
This year, DuPont's agriculture and nutrition division, which is based in Johnston
and includes Pioneer, will spend $588 million on product research and
development, said Courtney Chabot Dreyer, a Pioneer spokeswoman. The
company does not disclose how that money is allocated, but the majority goes to
Pioneer, she said.
"In some ways, you could say almost everything we are doing is to increase
yield," she said.
Monsanto Co. of St. Louis, Mo., a top Pioneer competitor, also is pushing to
increase corn's yield potential.
In the past decade, since biotechnology swept the crop seed industry, Monsanto
has invested more than $5 billion in crop seed research and development.
The company has led the industry in commercializing so-called stacked trait
hybrids, which combine two or three genetically engineered traits in a single
seed.
Robb Fraley, Monsanto's chief technology officer, told European investors last
month that conventional plant breeding on average results in 1.5 percent genetic
improvement per year, while molecular breeding - enabled by biotechnology doubles that rate of improvement. Together, the two approaches promise "to lift
the ceiling on yield," Fraley said in his presentation.
Weather and growing conditions also are crucial to corn yields. Monsanto,
Pioneer and other seed companies have tackled those barriers by developing
corn hybrids capable of thwarting pests, such as the European corn borer and
corn rootworms, for instance. In addition, the companies are working to increase
corn's tolerance of environmental stresses such as drought - globally, the single
largest source of lost yield potential.
In Arizona, Colorado and other arid places where corn is commonly irrigated,
yields routinely top 300 bushels per acre, said Kendall Lamkey, a professor of
agronomy and Pioneer distinguished chair in maize breeding at Iowa State
University. If researchers can make corn hybrids more tolerant of drought, that
would help boost production, he and others said.
"I think anything we do to increase drought tolerance will increase yields,"
Lamkey said.
During the past decade, the national yield average has fluctuated, increasing
some years but decreasing in others. Generally, though, the trend has been up,
and corn industry experts predict that yield increases will occur faster, in large
part because of technological advances.
Traditionally, it has taken 10 to 12 years to develop and commercialize a new
seed corn hybrid. Now, that time has been cut in half through the use of
biotechnology and off-season production in such places as Hawaii and South
America.
Lamkey expects corn yield increases to quicken in the next decade.
"I think there is still a lot of opportunity to increase corn yields," he said.
It hasn't hurt that corn breeders, both on campus and off, far outnumber those
working on genetic improvements in other crops, he said. Reducing the time it
takes to move a new hybrid from the laboratory to market also has helped.
"I don't think they can squeeze much more out of that, but that alone has really
enabled them to speed improvements," Lamkey said.