Debugging the Monsanto corn issue

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Reporter, Iowa Public Radio
Clay Masters reports for Iowa Public Radio. He previously reported for Harvest Public Media while based at NET Nebraska.

Crop consultant Ben Pinkelman oversees more than 30,000 acres of corn and soybeans in Nebraska. This summer, 3,000 of the corn acres showed signs of rootworm infestation.

"I've seen it on my south end, east end, west end, north end,” he said. “So I've seen it kind of my whole territory here in northeast Nebraska."

The signs of an infested field are fairly obvious. The stalks are tilted or just lie flat on the ground. That’s because the rootworms, like the name implies, are eating at the roots.

While the rootworm is a common foe for corn growers, the problem fields Pinkelman saw had something in common: They had been planted continuously with corn — primarily Monsanto’s Bt corn, which is engineered to express a trait known as Cry3bb1 protein that is supposed to kill the rootworm when the pests eat the plants’ roots.

"If we throw the same thing at it year after year after year after year it's going to beat us," Pinkelman said.

The Environmental Protection Agency agrees. In a report issued last month, the agency outlined the rootworm problem in fields surveyed in Iowa, Illinois, Minnesota and Nebraska. The report stated that the Bt corn seed, which has been on the market since 2003, may be losing some of its effectiveness against rootworm. The EPA also called Monsanto’s program for monitoring suspected cases of resistance “inadequate.”

Bt corn is planted on 37 million acres, according to Iowa Farmer Today.  And now — whether their crops have suffered or not — corn growers across the Midwest are weighing the significance of the EPA’s concerns.

As is Monsanto.

"We take the EPA's report very seriously and we do know that farmers have faced hot spots with high populations of rootworms for years, even prior to the introduction of insect-protected trait technologies," said MiMi Ricketts, a spokesperson at Monsanto. "Today there are geographical pockets of heavy rootworm infestation in areas where there's been a long history of corn-on-corn plantings."

Corn-on-corn planting has become fairly typical In Nebraska, said Bob Wright, a professor of entomology at the University of Nebraska-Lincoln. This is especially true, he noted, with cattle producers who need corn for feed.

"There's an economic incentive to grow your own corn rather than buy it for somebody else, especially with the higher value of corn these days," he said.

Investor considerations

    The Motley Fool, an investment web site, points out that Monsanto competitors may stand to benefit from the concerns raised about Bt corn: “Peers like DuPont and Dow Chemical, which offer similar genetically modified seeds, may take this opportunity to push their products harder. So far, DuPont's pest-resistant corn, developed with Dow, hasn't faced any issues. During its last quarter, DuPont also won approval for two new insect-protection products targeted at U.S. corn growers. But it isn't a death knell for Monsanto's corn seeds. One, it is the world's largest seed company. And two, demand for genetically modified feeds is growing globally, especially in emerging markets.”

Aaron Gassmann, an assistant professor of entomology at Iowa State University whose research was cited in the EPA report, warns about the consequences if management practices that led to problems in a few fields continue on a larger scale.

"It could become a substantial problem down the road if things don't change now," Gassmann said.

Farmers facing a rootworm infestation with genetically modified corn do have options. They can rotate their fields to a different crop like soybeans, a plant in which the rootworm cannot survive. They can switch to a different seed that has multiple traits that kill the rootworm. Or, they can switch to older methods of pest control like soil insecticides.

Pinkelman, the agronomist in northeast Nebraska, noted that rootworm resistance is an ongoing battle for farmers no matter what seed they plant. But he sees a broader concern.

"We've got a trait and these traits are supposed to be infallible is the general belief out there,” Pinkelman said. “It's never happened before. Insecticides have failed before, cultural controls have failed before — this is kind of a first."

The stakes are high. According to the Corn and Soybean Digest, roughly two-thirds of the U.S. corn crop has been genetically modified to ward off pests.