Paul Philips says:
Take the case of canola. The genes that allow the
canola
> > to be herbicide tolerant have spread by natural
polination
> > to almost all of the canola now produced -- but it
has also
> > spread to the weeds making them herbicide
resistant.
It has spread to all only in the sense if you tested a
field you would find a certain percentage of the
plants had the GM genes that confer glysophate
tolerance. If it had spread to nearly all most farmers
would consider that a blessing. They could use Roundup
without paying Monsanto for the seed. Note too that it
is NOT natural pollination that is the cause of most
of the presence of GM genes but other factors.
http://www.agrsci.dk/gmcc-03/abs_9.htm
At the time of unconfined commercial release of
Roundup Ready canola in Canada, it was known that
there was significant potential for out-crossing
within the canola (Brassica napus L.) genome and that
transgene movement from canola crop to canola crop
would occur (Canadian Food Inspection Agency 1995).
Work after the release and massive adoption of
GM-canola in western Canada has shown that pollen
mediated gene flow in canola can be an effective cause
of transgene movement. Beckie et al. (2001) and Rieger
et al. (2002) found that out-crossing in canola (B.
napus) occurred to a distance of 800 and 2500 m,
respectively. These studies helped in part to explain
why Friesen et al. (2003) and Downey and Beckie (2002)
found that a majority of the western Canadian grown
pedigreed non-GM canola (B. napus) seedlots they
tested contained genetically engineered herbicide
tolerance traits. This adventitious presence of
transgenes was not caused by pollen flow alone.
Thirty-three percent of the seedlots (9 of 27) tested
by Friesen et al. (2003), and 18% of the seedlots
tested by Downey and Beckie (2002) (13 of 70) had the
Roundup Ready transgene present at levels above 0.25%.
Given current knowledge of pollen mediated gene flow
in B. napus, it is unlikely that pollen flow would
cause greater than 0.1% presence in a single
generation of pedigreed seed production given strict
seed production protocols. Adventitious presence
levels above 0.25% were likely the result of
inadvertent mechanical mixing of certified seedlots
during harvest or handling, or contamination occurring
in earlier generations of pedigreed seed production
(i.e., Breeder or Foundation seed).
Phillips also says:
Note that the chemical firms' only
defense is that GMO seeds are no different from seeds
derived from
selective plant breeding though the widely reported
evidence is quite
quite contrary to this position.
The point that the firms make is that herbicide
tolerance is present in many seeds simply as a result
of a natural selection process. If you apply any
herbicide some weeds will often survive because they
have genetic features that are there naturally. If you
keep applying the same herbicide year after year these
weeds multiply and spread to other fields etc. When
herbicide resistant genes create the so-called super
weeds the same thing happens but more quickly perhaps.
If Roundup is used over and over again say, the weed
will live when others die. This is a problem by the
way for canola volunteers in ditches since some
municipalities use Roundup to kill weeds etc. in
ditches. The canola volunteers will not be killed.
Anyway the point the companies make is that
herbicide resistance is nothing new but it remains
true that GM modified plants with herbicide resistance
makes for even more problems. Whether they will be as
great as some of the doomsayers think I doubt very
much.
Anyway I hardly know anyone in our district who
grows anything but GM canola. I haven't heard them
complain about any superweeds but they do have to be
aware that if they grew GM glysophate tolerant canola
one year the next year if they grow a different crop
they will have to use a different herbicide to kill
any volunteer canola.
Cheers, Ken Hanly
--- Paul Phillips <[EMAIL PROTECTED]> wrote:
>
> Tom,
> Since when have Pen-l postings required reference
> footnotes when the
> information referred to is readily available and
> reported in government
> reports and in evidence provided in class action
> suits against Monsanto
> etc. Here, for instance is a report on superweeds
> related to canola
> published in the New Scientist. Note that the
> chemical firms' only
> defense is that GMO seeds are no different from
> seeds derived from
> selective plant breeding though the widely reported
> evidence is quite
> quite contrary to this position.
> Paul.
>
>
>
> Genetically-modified superweeds "not uncommon"
>
> * 15:34 05 February 2002
> * From New Scientist Print Edition. Subscribe
>
>
<http://www.newscientist.com/subscribe.ns?promcode=nsarttop>
> and
> get 4 free issues.
> * James Randerson
>
>
>
<http://www.newscientist.com/article.ns?id=dn1882&print=true>
>
> Oilseed rape plants resistant to three or more
> herbicides are "not
> uncommon" in Canada, says a report commissioned by
> English Nature, the
> UK government's advisory body on conservation.
>
> The so-called 'superweeds' result from accidental
> crosses between
> neighbouring crops that have been genetically
> modified to resist
> different herbicides. Farmers are often forced to
> resort to older
> stronger herbicides to remove them.
>
> Brian Johnson, at English Nature is alarmed by the
> speed of the process:
> "This has happened in three or four years," he says.
> The report predicts
> that, in the UK, plants with multiple herbicide
> resistance will be
> "almost impossible to prevent unless the crops are
> very widely dispersed."
>
> Adrian Bebb, of Friends of the Earth claims the
> research leaves a stark
> choice: "Either we keep the current separation
> distances between GM and
> non-GM crops, in which case contamination and gene
> stacking looks
> certain. Or we can have an effective separation
> distance - of at least
> three miles - in which case GM crops have no
> commercial future in the
> UK. There is no third way."
>
> However, Paul Rylott of biotech company Aventis
> argues many herbicide
> tolerant crops are created through conventional
> breeding, "GM crops are
> no different."
>
> He suggests that crossing between conventional
> varieties could have the
> same result. But Johnson notes that resistance bred
> into plant varieties
> tends to be much weaker and there is no evidence of
> 'superweeds' having
> been created in this way.
>
>
> Multiple resistance
>
> Oil seed rape, or canola, is typically alternated on
> a two-yearly cycle
> with a cereal crop such as wheat. Multiple resistant
> oil seed rape
> appears as a weed in the following year's crop,
> especially around field
> margins where seeds spilled during harvest can
> gather.
>
> The Canadian study found that these plants contained
> resistance genes
> from up to three GM varieties - so-called gene
> stacking. Farmers were
> forced to resort to a different and much more
> persistent herbicide,
> 2,4-D, to control them.
>
> Multiple resistant 'superweeds' would not be capable
> of taking over the
> countryside says Johnson. "They would only have an
> advantage in
> agricultural fields," he says. "But agricultural
> land is very important
> for biodiversity in Britain." So widespread use of
> persistent herbicides
> to remove the 'superweeds' could be disastrous.
>
> The biotechnology industry has admitted being slow
> to engage in the
> public debate over GM crops. "We haven't done a
> brilliant job in the
> past of selling the benefits of GM," says Tony
> Combes of Monsanto,
> "Support for GM is dependent on people being able to
> weigh the benefits
> against their concerns."
>
> An opinion poll commissioned by the industry and
> released on Tuesday
> suggests that two thirds of people feel they do not
> know enough about GM
> and that many would be more favourable to the
> technology if
> environmental or health benefits could be
> demonstrated.
>
>
>
>
> [EMAIL PROTECTED] wrote:
> > On 4/26/08,paul phillips said:
> >
> > > The problem of gmo seeds is much more pervasive
> > > than just 'invasive species'.
> >
> > What are your (peer reviewed?) sources for your
> "is" as distinguished
> > from, "possibly, may be"?
> >
> > > Take the case of canola. The genes that allow
> the canola
> > > to be herbicide tolerant have spread by natural
> polination
> > > to almost all of the canola now produced -- but
> it has also
> > > spread to the weeds making them herbicide
> resistant.
> >
> > What re your (peer reviewed?) sources for the
> implied "all" or "most"
> > and related implication that, if/when this occurs,
> the weeds referred
> > to are not herbicide resistant is comparatively
> easily controllable ways?
> >
> > > The result is the need for even greater
> applications
> > > of chemicals than before. In effect, the weeds
> have
> > > become an invasive species.
> >
> > DITTO for the "even greater, etc."
> characterization.
> >
> > And, BTW, doesn't "weeds" in this context (whether
> or not affected by
> > GMO canola) connote being "invasive" in any event?
> >
> >
> >
> > _______________________________________________
> > pen-l mailing list
> > [email protected]
> > https://lists.csuchico.edu/mailman/listinfo/pen-l
> >
> >
>
>
> --
> Paul Phillips Professor Emertus, Economics
> University of Manitoba Home
> and Office: 3806 - 36A st., Vernon BC, Canada. ViT
> 6E9 tel: 1 (250)
> 558-0830 email: [EMAIL PROTECTED]
> _______________________________________________
> pen-l mailing list
> [email protected]
> https://lists.csuchico.edu/mailman/listinfo/pen-l
>
Blog: http://kenthink7.blogspot.com/index.html
Blog: http://kencan7.blogspot.com/index.html
_______________________________________________
pen-l mailing list
[email protected]
https://lists.csuchico.edu/mailman/listinfo/pen-l
