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More on Plant Pesticides/EPA
Several scientists and others who generally view transgenic plants
as a step toward a better future have criticized the EPA's choice of words
in naming Bt-transgenics and herbicide tolerant varieties "plant
pesticides." Their concern is a real one; that the public's willingness to
accept the products of genetic engineering may be lessened by association
with something the public views negatively -- i.e., pesticides.
The EPA is holding its ground, for reasons that are unclear to me,
since they have done about everything else they could to encourage the
introduction of plant pesticides, including some decisions that will
inevitably increase the use of and risks from pesticide-dependent farming
systems. Bt-transgenic varieties are accurately labelled "plant-pesticides",
the Bt toxin is expressed throughout the plants tissue. In the case of
herbicide tolerant varieties, the name does not fit. It would be more
accurate to name a herbicide tolerant variety as a "pesticide-dependent
variety." It is unclear whether EPA will apply the name to other
genetically engineered varieties. It would clearly be inappropriate and
wrong to label a plant engineered to excrete through its roots a natural
substance that attracts beneficial soil microorganisms, thereby promoting
mircobial biocontrol of pathogens and insects. Such a variety might more
accurately be named a "plant health promoter".
By far the biggest issue now in the world of plant pesticides is
whether and when EPA will revoke the conditional registrations for the Bt
transgenics, as the law and their regulations seem to require under the
present circumstances. All these registrations were granted conditionally;
the key condition was that the companies must demonstrate, with verifiable
field data, the efficacy of the theoretical resistance management plans they
had submitted as part of the registration applications. All the plans were
and remain based on the "high dose" strategy, which was founded on
theoretical grounds and had never been demonstrated as practical in the
field. Recent findings and field experience with Bt transgenics have
completely undermined the always shaky foundation of the high dose strategy.
Anyone who believes in "good science" and studies recent data and findings
cannot avoid reaching the conclusion that today's resistant management plans
will not work for very long. Hence, a term of the conditional registrations
has been violated, and under the law, EPA should cancel the conditional
registrations.
EPA has not taken this step because they are apparently not yet
convinced that the Gould findings are relevant or persuasive. He found that
the frequency of naturally resistant alleles in cotton insects is 1,000 or
more times more common than Monsanto and other Bt transgenic registrants
hypothesized. He and other entomologists expect the same to hold true in
other major insects. As a result, the high dose strategy is doomed to fail.
Gould predicts widespread resistance in cotton country within a few years.
This seminal paper appeared in the Proc. of the NAS and is available through
their web site (go to <www.pnas.org>, do search on Gould, Fred and you will
see and can print for free the recent paper; it is also accessible through a
link on the PMAC web site, www.pmac.org, along with lots of other
information on these issues; go to section "Genetic Engineering"). Recent
papers and commentary by Bruce Tabashnik is also worth reading, and is also
found through the PNAS web site or PMAC. A summary of the physiological,
ecological and entomological reasons why Bt cotton will quickly lead to
resistance are summarized in the Benbrook-Hansen statement "Return to the
Stoneage..." presented March 21, 1997 at an EPA administrative hearing on Bt
transgenics and resistance, it is available at <www.pmac.net/stoneage.htm).
Greenpeace Int. and other environmental groups have just filed a
lawsuit against EPA on this very issue (announced yesterday on SANET). If
the case makes it to court, EPA is likely to face an embarrassing reversal.
New evidence undermining the science-base of the "high-dose strategy" is
surfacing from around the world. The question is whether EPA, regulatory
officials and agencies in other countries, the companies, and farmers will
heed it.
Note New New Address!!:
Charles Benbrook 208-263-5236 (voice)
Benbrook Consulting Services 208-263-7342 (fax)
5085 Upper Pack River Road benbrook@hillnet.com [e-mail]
Sandpoint, Idaho 83864 http://www.pmac.net