Another Take: Bt and Resistance

        I don't think Bob MacGregor interpreted what Ann Clarke was saying
correctly.  There is a huge difference between the prospects, timing, and
feasibility of managing resistance to conventional Roundup and Bt foliar
spray formulations.  While resistance has occurred to both from foliar
Roundup and Bt applications, the circumstances were unusual and not likely
repeated in most crops, and most importantly, would be EASY to avoid with a
modicum on commitment to biointensive IPM and resistance management.
Bt-transgenic plants and Roundup Ready beans are a totally different beast,
and will assuredly lead to resistance quickly (a few to 3-7 years), as even
Monsanto acknowledges in the case of Bt.  Monsanto and the other companies
developing these technologies are betting that they will win/hold enough
marketshare for 4-7 years to maximize their profits on chemicals which will
be falling by the wayside anyway.  By then, Roundup will be as cheap as
atrazine, a worn out generic with lots of better chemistry available, which
Monsanto will of course be force-feeding to all farmers to the extent they
can via control of the seed supply.

        On the Bt-transgenics side, it will be too late for Bt.  Once
resistance genes emerge in major target pests, the new Tabashnik report in
the "Proceedings of the NAS" (see http://www.pmac.net/tabash.htm) shows
clearly that it is likely the end of all 100 -- or 1,000 -- strains of Bt.
Resistance will emerge to new strains in a few generations, and the
economics will not justify any further development of transgenics.
Farmers/homeowners will be forced to shift to other, higher cost newer
proprietary chemicals, or lower-cost but higher-risk OPs, carbs, and
pyrethroids. That will be fine as far as the companies are concerned.  From
the "maximize profit" perspective of major ag chemical companies, it is a
brilliant strategy.  As soon as they control the seed supply, the rest of
us, including farmers, can ring their hands and complain about "technology
charges", restrictions on what farmers can do with their crops, and risk
outcomes, but the reality is farmers will have to plant the seed that is
available.  When farmers figure out whose ox is really being gored in all
this, watch out.  The political dynamics will shift in a big hurry, but alas
for Bt and no doubt a few other valuable products, it will be too late. 

        For lots more detail on resistance and Bt-transgenics, see the
Benbrook/Michael Hansen testimony "Return to the Stoneage of Pest
Management" presented before the March 21, 1997 EPA hearing on resistance
management and Bt-plant pesticides at <http://www.pmac.net/stoneage.htm>.  

Charles Benbrook                         202-546-5089 (voice)
Benbrook Consulting Services             202-546-5028  (fax)
409 First Street S.E.                    benbrook@hillnet.com   [e-mail]
Washington, D.C.  20003                  http://www.pmac.net