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April 2, 2000


Boll-dropping cotton and splitting soybean:


From: jonathan jones <

Subject: splitting headache

Hi, I had an interesting debate with some Greenpeacniks this weekend

They made much of the attached news of stemsplit in roundup ready soy

as an illustration of the fact that "we don't know what we're doing

disaster awaits". check this url


What is the position on this? How much more lignin do RR beans make?

Is it just some varieties where this happens or is it all of them?

thanks jonathan jones


From : Wayne Parrott <


ArialBoll-dropping cotton and
splitting soybean:

Reports are circulating widely that RR cotton and soybean differ in
their field behavior from their non-RR counterparts. RR cotton is said
to suffer from boll drop, while RR soybean is said to suffer from stem
splitting, in both cases leading to large yield losses. Both of these
cases are being used as examples that illustrate unintended side
effects with GMO crops. Two commentaries follow:

The first is by Dr. William B. McCloskey, Associate Extension
Specialist, Weed Science, Department of Plant Sciences, University of

I starting working with Roundup Ready Cotton in 1995 a couple of years
after Monsanto began field testing. At that time, it was clear that
the tolerance of Roundup Ready Cotton to glyphosate was not absolute
and I along with many others helped clarify how to use glyphosate with
out causing yield losses. The appropriate glyphosate use pattern for
RR cotton is specified in the section 3 EPA label. It is possible to
sometimes reduce yield by causing boll abortion if glyphosate is used
in NON_labeled ways and I have done this in some of my experiments.

Almost any herbicide input in any crop, non_transgenic or transgenic,
can be used in such a way as to cause crop injury and yield reductions
just as may beneficial human drugs can be used to commit suicide.
There is also the problem of misshappen and aborted bolls that occurred
due to environmental conditions. Both transgenic and non_transgenic
cotton varieties were affected similarly making it pretty remote that
Monsanto was culpable.

Some farmers in this area were going broke and looking for a deep
pocket to blame for their misfortune and since this was the first year
many grew RR cotton they felt that Monsanto was a good target. In the
case of soybeans I don't have much information and so I can't comment
other than to say that the acreage of RR soybeans has increased
dramatically and I have not heard of widespread problems at various
Weed Science Society meetings.

The second is by Dr. Wayne Parrott, Professor, Department of Crop and
Soil Sciences, University of Georgia.

Reports of splitting soybeans and subsequent yield losses started
circulating after my colleague, Dr. William Vencill, made a
presentation at the 1999 Brighton Conference Proceedings. For those
who want to see the information first-hand, it may be found in Gertz,
JM, WK Vencill, and NS Hill. Tolerance of transgenic soybean (Glycine
max) to heat stress. The 1999 Brighton Conference Proceedings _ Weeds
pp 835_840:

1) First, no mention of yield loss is made anywhere in the published
paper. The 40% yield loss figure that is being circulated came from a
report in New Scientist (20 November 1999), which reported a 40% crop
loss, not yield loss. The author, Dr. Vencill, whose office is down
the hall from mine, had conveyed a 40% stand reduction in his field to
the New Scientist reporter. This does not translate into a 40% yield
loss. The RR varieties he tested show a small yield decline as has
been reported on other RR varieties, but certainly not 40%! So, notice
how, as the story spreads, a 40% stand loss becomes misrepresented as a
crop loss which in turn gets misrepresented as a yield loss.

2) Stem splitting for Roundup Ready (RR) cultivars ranged from 90_100%;
while splitting rates for the nonRR cultivars were 60_70%. The LSD
(0.05) was 28%. Hence, the rate of splitting in RR varieties is just
marginally higher than that experienced by the nonRR varieties.

3) RR and non_RR versions of the same cultivar were never compared.
That was never the intent of the study. Hence, it is impossible to
determine if the increase in splitting, to the extent there is one, is
due to the transgene or to other genotypic effects, perhaps even
linkage drag.

Wayne Parrott

3111 Plant Sciences

Dept. of Crop and Soil Sciences

University of Georgia

Phone: 706-542-0926

FAX: 706-542-0914