- 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
- 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.
- © 2003 Independent Digital (UK) Ltd