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exchange between rick roush and joe Cummins over atrazine
Replying to Rick,
I am happy that Rick acknowledged that he is just another global pollutant.
Rick and Roger both believe that volunteer multiple resistant herbicides
are not "weeds" because they can be controlled by additional herbicide
applications such as 2,4-D. That should solve the problem of corporate
lawyer pests on the farm. Corporate lawyers should be eradicated but
added herbicide treatment seems threatening to the environment.
A reference on atrazine treatment of Brassica weeds including volunteer
That reference notes that atrazine resistance appears rapidly.
Further reading led me to find that atrazine tolerant canola was
recovered in Canada by breeding a wild tolerant brassica species to
create the crop that suffers yield loss but is grown because the
herbicide is very inexpensive. I read that western Canada limits use of
atrazine because of the carry over of the herbicide on prairie lands.
Eastern Canada , however, allows farming the atrazine resistant crop.
I truly fear that western canada may soon accept atrazine tolerant
canola. Hope this clears up the matter. Prof. Joe Cummins
Rick Roush wrote:
I have been occupied elsewhere for the last several days but note that
several more comments have come in about Joe Cummins's remarks.
I have the following responses to Joe's reply to my email, whose
comments are preceded by a ">". Readers can judge for themselves.
>Fan mail from Rick is as welcome as the coming of acid rain.
This is probably because Joe's position erodes so easily; the fact is,
his claims can't stand an acid test.
>His comments are certainly
>strange regarding the origin of multiple herbicide tolerant canola in
In his replies to me and Roger Morton, Joe apparently defines multiply
resistant canola as superweeds, as people writing for the popular media
are wont to do, whatever the realities. Volunteer canola plants are
weeds in other crops, but they don't constitute superweeds because they
are so easily controlled. Even the triple tolerant canola are sensitive
to other commonly used herbicides. I refer to a report from Smyth et al
in Nature Biotech; herbicide tolerant canola is controlled by other
herbicides such as 2,4-D, a cost of less than $2/acre. Some superweeds.
"Canola volunteers are not generally found to be harder to manage in
Canada. For example, a recent study prepared for the Canola Council of
Canada (Winnipeg) surveyed 650 western Canadian canola growers on
numerous issues, one of which was management of volunteer canola. Half
of the producers surveyed grew transgenic herbicide-tolerant canola and
half grew non-GM canola. Of the
producers planting transgenic herbicide-tolerant canola in 2000, 61%
the difficulty of managing volunteer transgenic herbicide-tolerant
about the same as that of volunteer conventional canola. Interestingly,
16% said that managing volunteer transgenic herbicide-tolerant canola
was easier than managing conventional canola varieties. The remaining
23% said that it was
more difficult to manage volunteer transgenic herbicide-tolerant
canola.... for example, spraying with 2,4-dichlorophenoxyacetic acid
(2,4-D) controls this problem. This chemical application means an
additional cost to the producer of 1.50-2.00 Canadian dollars (C$) per
acre" (source: Stuart Smyth, George G. Khachatourians & Peter W.B.
Phillips, Liabilities and economics of transgenic crops. Nature
Bio/Technology (June) 2002 Volume 20 (Number 6) pp 537 - 541)
Under Australian conditions, at least, farmers would generally have to
be using a "broadleaf" herbicide anyway, especially in the cereal phase
of their rotations, because glyphosate (the active of Roundup) is not
especially effective for broadleaved weeds (it's most effective on
grasses). Joe, with the apparent exception of one or two farmers in
Sask, most farmers are smart enough to simply control volunteers and not
to invite being sued by deliberately saving seed they know to be
resistant to glyphosate!
> Even corporations , as shown in the quote below (taken
>from a full report of mine quoting a commercial report)agree that the
>canola volunteer super weeds arise by pollen exchange between patented
>crops (there are peer reviewed publications on this topic).
No question about how multiply tolerant volunteers can arise; the
question is what's the extent of the problem. The most famous case (that
documented by Linda Hall and colleagues in Weed Science 2000, 48,688-94)
arose when a farmer unwisely planted three varieties on the same farm
right next to each other, and probably even had mixing of varieties in
>I am not aware of the commercial use of atrazine tolerant canola or any
>other crop in Canada at this time. My understanding has been that
>atrazine tolerant volunteers are shunned because of yield deficiency.
>However, as I pointed out corn and some other grasses are naturally
>tolerant to the herbicide. I cannot find any literature report on
>spontaneous atrazine tolerant crop volunteers that do not suffer yield
>deficiency. The use of atrazine tolerant crops in Ontario and Quebec is
>a frightful prospect because the farm wells are known to be polluted
>with the herbicide as are the rivers and lakes,including the great
>lakes. The other disadvantage is the carry over of atrazine in the soil
>that prevents rotation with legumes and leads to years of cropping
In my original email, I stated that "I have yet to see any suggestion to
use atrazine to control ("superweeds"), in direct contradiction to the
claim of Cummins and Ho" and further asked "him to identify these
anonymous "authorities"; if they exist at all, I would challenge their
In a fairly typical fashion, Joe has not directly admitted that he could
not provide any support for his claims that atrazine was needed to deal
with his so-called superweeds, but instead has written about atrazine
tolerant crops, and how he finds them frightful. As Roger Morton noted,
the sources Joe refers to do not mention atrazine.
As I noted in my original email, atrazine tolerant canola is already
being grown on large areas of Australia. Joe's claimed fright is
apparently not great enough to force him to consider the choice that
Australians must make; whether atrazine-tolerant canola (including their
yield deficiency) or Roundup Ready canola is less likely to be a threat
to human health or the environment. Can people like Joe come to a
reasoned decision on this, or will we continue to see nothing but
criticisms without practical recommendations?