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'Superweeds' signal setback for GM crops
(Tuesday, June 24, 2003 -- CropChoice news) -- Michael McCarthy, The Independent (UK), 06/23/03: The dispute over genetically modified crops will intensify today with news
of the evolution of "superweeds", which are resistant to the powerful
weedkillers that GM crops were engineered to tolerate.
The development, which comes as the sacked former environment minister
Michael Meacher puts himself at the head of the anti-GM campaign, will be
seized on by opponents of the technology as undermining its rationale.
It means that bigger quantities of weedkillers - not less, as the
biotechnology companies have claimed - will be needed in GM-crop fields,
adding to the already intensive agriculture that has wiped out much of
Britain's farmland wildlife in the past four decades. Monsanto, the GM
market leader, confirmed to The Independent at the weekend that its
solution for dealing with resistant weeds was to apply different
weedkillers in new ways.
In yesterday's Independent on Sunday, Mr Meacher accused Tony Blair, a GM
supporter, of seeking to bury health warnings about GM produce by "rushing
to desired conclusions which cannot be scientifically supported".
The revelations about superweeds have been communicated to the Government
by an American academic specialising in weed control, who has posted a
paper on the website of the official GM science review, led by Professor
David King, the Government's chief scientific adviser. This will report
soon in advance of a long-delayed decision, due this autumn, on whether GM
crops should be commercialised in Britain.
The paper, by Professor Bob Hartzler of the Department of Agronomy at Iowa
State University, reveals that in the past seven years, up to five weed
species have been found with resistance to the herbicide glyphosate, best
known by the Monsanto trade name Roundup. The resistance has come about
not through gene transfer from GM herbicide-tolerant crops, as some have
feared, but through natural evolution.
Glyphosate is a "broad spectrum" herbicide, meaning that, originally, it
killed everything, including crops. GM crops were developed to be tolerant
of the herbicide, so it could be applied throughout the growing season.
Two GM crops proposed for commercial growth in Britain, fodder beet and
sugar beet, are glyphosate-tolerant. But weeds have been found in
Australia, Chile, Malaysia and California and other areas of the US, that
glyphosate cannot kill.
Greg Elmore, Monsanto's US technical manager for soybeans, said Monsanto
was taking seriously the question of glyphosate resistance, tackling it
with "weed control management practices".
With soybeans, he said, resistant weeds were controlled with a
pre-planting "burn-down" (which kills everything), using 2,4-D, another
weedkiller.
At least three of the resistant weeds had evolved where glyphosate was
being used with non-GM crops, he said, adding that it was far from the
only weedkiller for which weeds had evolved resistance - as many as 70
weeds were resistant to some weedkillers.
Pete Riley, Friends of the Earth's GM campaigner, said: "Companies like
Monsanto have spun GM crops and their weedkillers as having less impact on
the environment, but the fact of resistant weeds undoubtedly means more
weedkillers, and means the impact on the environment will be greater.
"These discoveries remove a central plank from the whole argument for GM
crops."
Yesterday, Mr Meacher listed a series of reports and findings suggesting
that the full impact of GM technology was still dangerously unpredictable.
Many of the health tests carried out were "scientifically vacuous", he
said.
http://news.independent.co.uk/uk/environment/story.jsp?story=418070 | |
