Wash Post. 1/9/99 Biotech Companies Worried About Bt Resistance:
Ronnie Cummins (email@example.com)
Mon, 11 Jan 1999 10:28:43 -0600 (CST)
>Corn Seed Producers Move to Avert Pesticide Resistance
>By Rick Weiss
>Washington Post Staff Writer
>Saturday, January 9, 1999; Page A04
>Responding to pressure from federal regulators, environmentalists and
>others, a coalition of the nation's major producers of genetically
>engineered corn seed said yesterday that they would require farmers to
>grow sizable plots of non-engineered, old-fashioned corn along with
>their new biotechnology varieties.
>The companies hope to allay increasing fears among scientists that some
>newly marketed varieties of gene-altered corn, which exude potent
>insecticides day in and day out, may be speeding the evolution of
>pesticide-resistant "super" insects.
>The announcement, which caught many farmers and others by surprise, was
>announced by an official of St. Louis-based Monsanto Co., the country's
>largest producer of gene-altered corn, at an Environmental Protection
>EPA officials welcomed the coalition's plan with cautious optimism. "We
>have not had an opportunity to review the details of this agreement.
>However, we hope the final version will contain the elements EPA feels
>are required for the effective management of these products," Loretta
>Ucelli, EPA's associate administrator of public affairs, said in a
>But the plan was immediately criticized as inadequate by some scientists
>and environmental activists, who noted that it calls for plots of
>non-engineered crops to be about half the size that several research
>studies have recently determined will be needed to prevent ecological
>"It's like having your doctor prescribe five pills a day to prevent a
>heart attack: It might help a little bit to take only one, but probably
>you're going to die," said Jane Rissler, senior staff scientist at the
>Union for Concerned Scientists in Washington. "These companies are
>responding to an overwhelming scientific consensus that they have to do
>something, but what they are proposing is far, far from what is needed."
>The more that insects are exposed to an insecticide, the more rapidly
>they develop resistance to that pesticide. That principle has become an
>issue as several companies have added a gene to corn that allows the
>plants to produce a steady supply of an insecticide known as bt, a
>bacterial toxin that kills European corn borers and related caterpillars
>that drill through stalks and damage ears.
>Growers who use the new varieties can avoid spraying bt during the
>season. But periodic spraying, though expensive and troublesome for
>growers, is in some respects more environmentally friendly. That's
>because bt breaks down quickly in sunlight, keeping exposures so brief
>that insects hardly have the opportunity to evolve strategies for
>becoming resistant to the chemical.
>Under constant chemical pressure from bt-exuding plants, insects have
>greater opportunity to evolve ways of being unfazed by bt.
>Field studies and computer modeling experiments have confirmed that
>there is a solution to the problem: Grow plots of normal corn near the
>bt plots, and don't spray those "refuges" with any bt. Without the
>pressure to develop bt resistance, insects on refuge plots tend to
>remain susceptible to the pesticide. And when those insects mate with
>their neighbors in nearby biotech plots, their susceptibility genes will
>dilute any emerging resistance in their mates.
>But how big do these refuges have to be? Several recent studies, which
>have been compiled into a document that EPA now relies heavily upon,
>have concluded that a refuge kept completely free of pesticides must be
>20 percent to 30 percent the size of the engineered plot. They note that
>a refuge should be about 40 percent the size of the biotech plot if
>pesticides are to be used, since spraying can increase the odds of bt
>The new plan, however, calls for only 20 percent refuges, even when
>sprays are to be used, said Monsanto spokesman Dan Holman. Moreover, the
>plan offers no details about whether the refuges must be planted
>alongside the biotech plots, or can be some distance away, where studies
>suggest they would be less effective.
>"I think it's important that they've come up with something, even a
>compromise," said Fred Gould, an entomologist and bt expert at North
>Carolina State University in Raleigh. "But the bottom line is, 20
>percent without spraying is as low as you'd want to go."
>Indeed, the EPA has recently been requiring refuges about twice as big
>as what yesterday's plan proposes for newly registered varieties of bt
>corn. But previously approved varieties, including those made by the
>companies that came up with the plan, were registered by the EPA before
>the agency started insisting on refuges. That means any such system is
>voluntary for them until those registrations start to expire in 2002,
>even though they account for most of the 15 million acres of engineered
>corn now planted in this country.
>Holman said the coalition would release more details later, including
>how it intends to enforce the use of the refuge system among farmers.
>© Copyright 1999 The Washington Post Company
Campaign for Food Safety/Organic Consumers Action
860 Hwy 61
Little Marais, Mn. 55614
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