Need Safeguards for Gene-Tinkered Foods

Toby Bradshaw toby at stein.u.washington.edu
Sat Jun 26 10:50:06 EST 1993


In article <C97B98.1HA at dartvax.dartmouth.edu> James.F.X.Wellehan at dartmouth.edu (Jim Wellehan) writes:
>In article <1993Jun25.112716.21142 at nstn.ns.ca>
>dc_ags at ac.nsac.ns.ca (Don Christie) writes:
  
>> `(promoting use of polluting chemicals)' ?? From what I've been able
>> to gather, anything that doesn't *slam* agrichemical use is by default
>> `promoting' them as far as some people are concerned.
>
>It would seem herbicide resistance would be good for only one purpose; 
>allowing higher levels of herbicides to be used.  That would definitely
>promote use of polluting chemicals.  The biological alternatives to
>pesticides, etc. that you mentioned are definitely a more rational
>approach to modern farming.

"Definitely"?  You have a certainty that most scientists lack.  A
"good" example of herbicide tolerance (IMHO, naturally), is
glyphosate (Roundup).  Glyphosate is relatively benign, with a
half-life in soil of a few days.  Because it is toxic to all
green plants, it is presently used as a non-selective herbicide.
If glyphosate tolerance were introduced into crop plants, I think
we can safely assume that Monsanto will sell more Roundup.  I think
we can further assume that this potential profit motive drives
their interest in the subject.  If and when glyphosate-tolerant
soybeans (say) come to market, will the environmental cost be
more or less than other forms of weed control?  You seem certain
that this answer is "higher environmental cost".  I'm not so sure.
Glyphosate could potentially replace or reduce mechanical cultivation,
leading to reduced erosion with the tradeoff that more "chemicals"
are used.  Are you capable of tallying the relative costs, direct
or indirect, of each approach?  I'm not, so I won't rule out one
option, that of genetically-engineered glyphosate tolerance.  Perhaps
folks would feel better about glyphosate if it could be found
as a "natural" allelopathic herbicide in some free-living plant
and if glyphosate tolerant mutants of crops were selected rather
than engineered.  Frankly, I don't see the difference.  As for
a "polluting" chemical, perhaps you might take a look at the
structure of glyphosate, its (in)stability in the biosphere, and
point out where the "danger" lies.

Toby Bradshaw                       |
Department of Biochemistry          |  Will make genetic linkage maps
and College of Forest Resources     |            for food.
University of Washington, Seattle   |
toby at u.washington.edu               |



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