Corn Seed Producers Move to Avert Pesticide Resistance
- To: Ban-GEF@lists.greenbuilder.com, email@example.com
- Subject: Corn Seed Producers Move to Avert Pesticide Resistance
- From: MichaelP <papadop@PEAK.ORG>
- Date: Sat, 9 Jan 1999 14:13:26 -0800 (PST)
- Content-Type: TEXT/PLAIN; charset=US-ASCII
- Resent-From: firstname.lastname@example.org
- Resent-Message-ID: <"saAF5.A.thC.CT9l2"@bakunix.free.de>
- Resent-Sender: email@example.com
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 Agency meeting.
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 statement.
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
"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 resistance developing.
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.
** NOTICE: In accordance with Title 17 U.S.C. Section 107, this material
is distributed without profit to those who have expressed a prior interest
in receiving the included information for research and educational