GM crops linked to rise in pesticide use

http://www.guardian.co.uk/uk_news/st...118170,00.html

GM crops linked to rise in pesticide use

John Vidal
Thursday January 8, 2004
The Guardian

Eight years of planting genetically modified maize, cotton and soya
beans in the US has significantly increased the amount of herbicides
and pesticides used, according to a US report which could influence
the British government over whether to let GM crops be grown.
The most comprehensive study yet made of chemical use on genetically
modified crops draws on US government data collected since
commercialisation of the crops began.

It appears to undermine one of the central selling points of GM
farming - that the crops benefit the environment because they need
fewer manmade agrochemicals.

Charles Benbrook, the author of the report, who is also head of the
Northwest Science and Environment Policy Centre, at Sandpoint, Idaho,
found that when first introduced most of the crops needed up to 25%
fewer chemicals for the first three years, but afterwards
significantly more.

In 2001, the report states, 5% more herbicides and insecticides were
sprayed compared with crops only of non-GM varieties; in 2002 7.9%
more was sprayed; and in 2003 the estimated rise was 11.5%. In total,
£73m more agrochemicals were sprayed in the US during 2001-2003
because of GM crops, says the report, which was commissioned by Iowa
State University, the Consumers' Union and others.

During 2002-2003, an average of 29% more herbicide was applied per
acre on GM maize. But this trend was not sustained over the eight
years. Overall, modest reductions in insecticide usage with maize and
cotton were recorded, with no sign thatthe pests were starting to
build up resistance.

UK farm trials found that two of the three GM crops grown
experimentally in Britain, oil seed rape and sugar beet, were more
harmful to the environment than conventional crops but that GM maize
allowed the survival of more weeds and insects. The key to insects'
and weeds' survival was the quantity of chemicals used on either
conventional or GM crops.

Dr Benbrook said: "The proponents of biotechnology claim GM varieties
substantially reduce pesticide use. While true in the first few years
of widespread planting ... it is not the case now. There's now clear
evidence that the average pounds of herbicides applied per acre
planted to herbicide-tolerant varieties have increased compared to the
first few years."

Last night, the Agriculture Biotechnology Council, a British GM
industry trade group, criticised the findings, saying it was not
possible to directly correlate pesticide use with GM crops. "There are
lots of seasonal conditions that have effects [on how much pesticide
is used]. Global warming is also important. We do not dispute that
there was a 20% increase [of pesticides] in 2002 over 2001, but that
[2001] was the lowest figure in years."

Peter Melchett, policy director of the Soil Association, said
yesterday: "This is compelling evidence that GM maize will lead to
higher spray use and serious damage to wildlife if the crop is grown
in this country.

"The biotechnology companies have been claiming that GM crops result
in large reductions in the use of sprays, and GM maize is their
frontrunner for commercial growing in the UK. Until now, there has
been no clear evidence over the whole eight years of commercial
growing in the US to show their claims are false - that's what the
evidence in this report gives us.

"It would be inconceivable for the government to give the go-ahead to
GM maize now this damning evidence is out."

However, one of the most important factors involved in the increase of
herbicides is thought to have been the recent termination of the
patent protection for glyphosate herbicide, made by the leading GM
company Monsanto. This is the main chemical the plants are engineered
to tolerate.

According to the report, new, competing products have halved prices
and encouraged more spraying.

· Tony Blair yesterday said that public opinion would play a part in
the development of GM products in the UK. Speaking at prime minister's
question time about what impact recent government soundings would have
on a final decision on GM in Britain, he said it was "vital that we
proceed - by public consultation but also on the basis of the science
of GM".

Special reports
GM food debate
Special report: what's wrong with our food?

Explained
03.06.2003: GM crops

May 2003 investigation
Food: the way we eat now

Useful links
GM public debate - the official site
Monsanto
Agriculture & environment biotechnology commission (government
advisory body)
Agricultural Biotechnology Council

Official reports
Royal Society report on GM plants (pdf)
Parliamentary Office of Science and Technology report on GM food
labelling (pdf)
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