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Date:

April 5, 2000

Subject:

Boll Drop, Heat Stress in RR Beans

 

- http://www.agbioworld.org, http://agbioview.listbot.com


I would like to respond to some misinformation concerning boll drop in
Roundup Ready cotton and heat stress in Roundup Ready soybeans mentioned in
the message by Chuck Benbrook, and in other recent messages.

I led the investigation of the boll drop situation that occurred in Roundup
Ready cotton in 1997. This investigation included collecting data from over
400 Roundup Ready and conventional cotton fields. This situation was
clearly not a "pleiotropic effect" as suggested. In an early message on
AgBioView, Dr. William McCloskey of the University of Arizona clearly
outlined the limitations of Roundup applications in Roundup Ready cotton.
Boll drop is a result of improper Roundup applications (or other
environmental/management effects such as heat sterility, too much nitrogen,
heavy rainfall, etc.) and is not a pleiotropic effect.

Dr. Wayne Parrott of the University of Georgia did a good job of clarifying
the heat stress testing in Roundup Ready soybeans in an earlier message.
One of the most important statements by Dr. Parrott is that "RR and non-RR
versions of the same cultivar were not compared". This is an important
point that frequently comes up in transgenic testing, i.e. the genotype
differences that invariably occur between the transgenic and non-transgenic
versions that can contribute to observed differences. These genotype
differences come about through the backcrossing and line selection process
of incorporating the gene into a new variety. Only when true isolines are
produced can these "single-genotype" comparisons be made with a high degree
of confidence.

Monsanto is very concerned about the safety and performance of crops
containing our genes. We do extensive testing on new traits to make sure
there are no "unanticipated responses". This includes extensive testing on
isolines.

It is unfortunate that (mis-)information that has no basis in fact gets
widely circulated and is subsequently quoted as true and factual.

Richard Voth, Ph.D.
Cotton Technology Team
Monsanto Co.



-----Original Message-----
From: Chuck Benbrook [mailto:benbrook@hillnet.com]
Sent: Tuesday, April 04, 2000 11:47 AM
To: AgBioView
Subject: Boll Drop, Heat Stress in RR Beans


- http://www.agbioworld.org, http://agbioview.listbot.com

In response to Jonathan Ewer's comment that there is no reason for
concern re boll drop and heat stress in RR beans, I agree that the market
will determine whether such performance problems render the technologies no
longer "value added" to the farmer. But I disagree that such problems are
irrelevant re safety assessments. These sort of erratic production problems
are examples of observable pleiotropic effects, the sort of which many
scientists have anticipated. The fact that they are occurring, and in some
varieties under a seemingly wide range of circumstances, should raise a flag
for all scientists sincerely interested in understanding the physiological
and other unanticipated responses of transgenic crops under conditions of
stress. Does anyone on this list know of a scientific reason/logic why one
would hypothesize that a variety experiencing a pleiotropic effect like boll
drop would be less likely to manifest others?

chuck benbrook