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2-Plants: Transgenic crop may have bred with wild weed



                                  PART I
-------------------------------- GENET-news -------------------------------

TITLE:  GM crops created superweed, say scientists
SOURCE: The Guardian, UK, by Paul Brown
        http://www.guardian.co.uk/gmdebate/Story/0%2C2763%2C1535428%2C00.html
DATE:   25 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


GM crops created superweed, say scientists
Modified rape crosses with wild plant to create tough pesticide-resistant
strain

Modified genes from crops in a GM crop trial have transferred into local
wild plants, creating a form of herbicide-resistant "superweed", the
Guardian can reveal.

The cross-fertilisation between GM oilseed rape, a brassica, and a
distantly related plant, charlock, had been discounted as virtually
impossible by scientists with the environment department. It was found
during a follow up to the government's three-year trials of GM crops
which ended two years ago.

The new form of charlock was growing among many others in a field which
had been used to grow GM rape. When scientists treated it with lethal
herbicide it showed no ill-effects.

Unlike the results of the original trials, which were the subject of
large-scale press briefings from scientists, the discovery of hybrid
plants that could cause a serious problem to farmers has not been announced.

The scientists also collected seeds from other weeds in the oilseed rape
field and grew them in the laboratory. They found that two - both wild
turnips - were herbicide resistant.

The five scientists from the Centre for Ecology and Hydrology, the
government research station at Winfrith in Dorset, placed their findings
on the department's website last week.

A reviewer of the paper has appended to its front page: "The frequency of
such an event [the cross-fertilisation of charlock] in the field is
likely to be very low, as highlighted by the fact it has never been
detected in numerous previous assessments."

However, he adds: "This unusual occurrence merits further study in order
to adequately assess any potential risk of gene transfer."

Brian Johnson, an ecological geneticist and member of the government's
specialist scientific group which assessed the farm trials, has no doubt
of the significance. "You only need one event in several million. As soon
as it has taken place the new plant has a huge selective advantage. That
plant will multiply rapidly."

Dr Johnson, who is head of the biotechnology advisory unit and head of
the land management technologies group at English Nature, the government
nature advisers, said: "Unlike the researchers I am not surprised by
this. If you apply herbicide to plants which is lethal, eventually a
resistant survivor will turn up."

The glufosinate-ammonium herbicide used in this case put "huge selective
pressure likely to cause rapid evolution of resistance".

To assess the potential of herbicide-resistant weeds as a danger to
crops, a French researcher placed a single triazine-resistant weed, known
as fat hen, in maize fields where atrazine was being used to control
weeds. After four years the plants had multiplied to an average of
103,000 plants, Dr Johnson said.

What is not clear in the English case is whether the charlock was
fertile. Scientists collected eight seeds from the plant but they failed
to germinate them and concluded the plant was "not viable".

But Dr Johnson points out that the plant was very large and produced many
flowers.

He said: "There is every reason to suppose that the GM trait could be in
the plant's pollen and thus be carried to other charlock in the
neighbourhood, spreading the GM genes in that way. This is after all how
the cross-fertilisation between the rape and charlock must have occurred
in the first place."

Since charlock seeds can remain in the soil for 20 to 30 years before
they germinate, once GM plants have produced seeds it would be almost
impossible to eliminate them.

Although the government has never conceded that gene transfer was a
problem, it was fear of this that led the French and Greek governments to
seek to ban GM rape.

Emily Diamond, a Friends of the Earth GM researcher, said: "I was shocked
when I saw this paper. This is what we were reassured could not happen -
and yet now it has happened the finding has been hidden away. This is
exactly what the French and Greeks were afraid of when they opposed the
introduction of GM rape."

The findings will now have to be assessed by the government's Advisory
Committee on Releases to the Environment (Acre). The question is whether
it is safe to release GM crops into the UK environment when there are
wild relatives that might become superweeds and pose a serious threat to
farm productivity. This has already occurred in Canada.

The discovery that herbicide-resistant genes have transferred to farm
weeds from GM crops is the second blow to the hopes of bio-tech companies
to introduce their crops into Britain. Following farm scale trials there
was already scientific evidence that herbicide-tolerant oilseed rape and
GM sugar beet were bad for biodiversity because the herbicide used to
kill the weeds around the crops wiped out more wildlife than with
conventionally grown crops. Now this new research, a follow-up on the
original trials, shows that a second undesirable potential result is a
race of superweeds.

The findings mirror the Canadian experience with GM crops, which has seen
farmers and the environment plagued with severe problems.

Farmers the world over are always troubled by what they call "volunteers"
- crop plants which grow from seeds spilled from the previous harvest, of
which oilseed rape is probably the greatest offender, Anyone familiar
with the British countryside, or even the verges of motorways, will
recognise thousands of oilseed rape plants growing uninvited amid crops
of wheat or barley, and in great swaths by the roadside where the "small
greasy ballbearings" of seeds have spilled from lorries.

Farmers in Canada soon found that these volunteers were resistant to at
least one herbicide, and became impossible to kill with two or three
applications of different weedkillers after a succession of various GM
crops were grown.

The new plants were dubbed superweeds because they proved resistant to
three herbicides while the crops they were growing among had been
genetically engineered to be resistant to only one.

To stop their farm crops being overwhelmed with superweeds, farmers had
to resort to using older, much stronger varieties of "dirty" herbicide
long since outlawed as seriously damaging to biodiversity.

Q&A: What the discovery means for UK farmers

What's the GM situation in the UK?

No GM crops are currently grown commercially in the UK. Companies who
wish to introduce them face a series of licensing hurdles in Britain and
Europe and interest has waned in recent years amid public opposition.

Other firms have dropped applications in the wake of the government field
scale trials that showed growing two GM varieties - oilseed rape and
sugar beet - was bad for biodiversity.

The EU has approved several GM varieties and the UK government insists
that applications will be considered on a case-by-case basis.

Where are GM crops grown?

Extensively in the wide open spaces of the US, Canada and Argentina. In
Europe, Portugal, France and Germany have all dabbled with GM insect-
resistant maize. Spain plants about 100,000 hectares (250,000 acres) of
it each year for animal feed.

What is a superweed?

Many GM crop varieties are given genes that allow them to resist a
specific herbicide, which farmers can then apply to kill the weeds while
allowing the GM crop to thrive.

Environmental campaigners have long feared that if pollen from the GM
crop fertilised a related weed, it could transfer the resistance and
create a superweed. This "gene transfer" is what appears to have happened
at the field scale trial site. It raises the prospect of farmers who grow
some GM crops being forced to use stronger herbicides on their fields to
deal with the upstart weeds.

Is it a big problem?

Not yet. Farmers in the UK do not grow GM crops commercially. If they
did, then the scale of possible superweed contamination depends on two
things: whether the hybrid superweed can reproduce (many hybrids are
sterile) and, if it could, how well its offspring could compete with
other plants. Herbicide-resistant weeds could potentially grow very well
in agricultural fields where the relevant herbicide is applied. Most
experts say superweeds would be unlikely to sweep across the UK
countryside as, without the herbicide being used to kill their
competitors, their GM status offers no advantage.

Some GM crops, such as maize, have no wild relatives in the UK, making
gene transfer and the creation of a superweed from them impossible.

Is it a surprise?

On one level no, gene flow and hybridisation are as old as plants
themselves. Short of creating sterile male plants, it's simply impossible
to stop crops releasing pollen to fertilise related neighbours. But
government scientists had thought that GM oilseed rape and charlock were
too distantly related for it to occur.

The dangers of hybridisation where it does happen are well documented -
experts from the Dorset centre behind the latest research published a
high-profile paper in 2003 in the US journal Science showing widespread
gene flow from non-GM oilseed rape to wild flowers.

Have superweeds surfaced elsewhere?

Farmers in Canada and Argentina growing GM soya beans have large problems
with herbicide-resistant weeds, though these have arisen through natural
selection and not gene flow through hybridisation. Experiments in Germany
have shown sugar beets genetically modified to resist one herbicide
accidentally acquired the genes to resist another - so called "gene
stacking", which has also been observed in oilseed rape grown in Canada.
- David Adam


                                  PART II
-------------------------------- GENET-news -------------------------------

TITLE:  Transgenic crop may have bred with wild weed
SOURCE: Nature, UK, by Michael Hopkin
        http://www.nature.com/news/2005/050725/full/050725-2.html
DATE:   25 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


Transgenic crop may have bred with wild weed
Oilseed rape hybrid unlikely to become 'superweed', say researchers.

British researchers have found evidence that transgenic oilseed rape in
test plots is interbreeding with related wild species, raising fears that
herbicide-tolerance could spread among weeds.

The government-funded research, carried out at the Centre for Ecology and
Hydrology (CEH) in Dorset, UK, suggests that oilseed rape, Brassica
napus, may have hybridized with charlock, Sinapis arvensis, a related
weed species.

Surprisingly, one of the suspected crosses appears to be a healthy,
fertile plant. But, researchers add, concerns that 'superweeds' will take
over fields are unfounded.

Herbicide-tolerant weeds would mostly be a problem for farmers trying to
rid their fields of unwanted plants, comments Les Firbank, a crop
researcher at the CEH research station in Lancaster, who led Britain's
previous farm-scale evaluations of the effects of transgenic crops on
biodiversity. "It's a management problem for farmers, not an
environmental problem," he says.


Mix and match

In the three-year study, researchers analysed weed species growing in 28
fields sown half with transgenic oilseed rape and half with non-
transgenic crop. They identified two plants that seem to possess
characteristics of both oilseed rape and charlock.

One fertile plant resembled charlock, but was not killed by the Liberty
herbicide that the oilseed rape had been engineered to be resistant
against. When the researchers extracted and analysed its DNA, they
identified the genetic sequence that confers this tolerance1.

Another plant, found in the middle of a non-transgenic plot, seemed to
have physical characteristics halfway between those of oilseed rape and
charlock, showing that the two species can hybridize. This plant was
infertile.

Some environmental groups are claiming this is evidence that transgenes
can escape into the plant community at large. Emily Diamand, a
spokesperson for campaign group Friends of the Earth, comments that
"we're seeing the real possibility of superweeds being created".


Natural selection

But the plants are not necessarily cause for worry, comments Brian
Johnson, an ecological geneticist with English Nature, which advises the
government on wildlife issues. "Quite frankly, this does not demonstrate
the creation of anything resembling a superweed," he told news@nature.com.

Johnson points out that the herbicide-resistant wild plant identified in
the study may not be a true hybrid. The technique used to identify the
gene sequence is very sensitive, and could simply have picked up
contamination from oilseed-rape pollen, and the herbicide resistance seen
in the plant itself could have arisen naturally, he argues.

Even if it were a true hybrid, the resistance to Liberty herbicide would
be unlikely to confer a benefit outside that field, so the plant would
not be expected to spread widely.

As for the hybrid plant found in the middle of the plot, Johnson says
"it's one thing to be a robust plant, but that doesn't mean anything if
you're firing blanks."


One at a time

The finds are not entirely unexpected: oilseed rape has previously been
found to hybridize with wild turnip. However, in a comment attached to
the report, the study's confidential reviewer says, "this unusual
occurrence merits further study."

Johnson remains confident that, with careful management, 'superweeds'
resistant to several herbicides will not arise. One tactic is not to
license different crops with engineered resistance to different
weedkillers. They should be made resistant to one weedkiller at a time,
he suggests.

The discovery may be of interest in the United States, where herbicide-
tolerant crops are widely grown. "Farmers will have to pay attention to
how they manage their crops with herbicide," Firbank says.


References

	1 Daniels R., Boffey C., Mogg R., Bond J. & Clarke R. Report to DEFRA,
http://www.defra.gov.uk/environment/gm/research/pdf/epg_1-5-151.pdf
(2005).


                                  PART III
-------------------------------- GENET-news -------------------------------

TITLE:  Scientists play down 'superweed'
SOURCE: British Broadcasting Corporation
        http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/4715221.stm
DATE:   25 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


Scientists play down 'superweed'
Scientists have urged caution over a study which may have found a so-
called "superweed" growing at a site where GM crops had been trialled.

The charlock, a relative of oilseed rape, failed to shrivel up when
daubed with the herbicide used to manage a biotech crop grown in the same
field.

The creation of wild plants that pick up the traits of engineered crops
has long been feared by anti-GM groups.

But researchers said their work showed the chances of such transfer were slim.

What is more, they argued, the study reinforced the view that the
environmental impact was negligible.

"Herbicide-tolerant weeds tend to under-perform compared with wild type,
so unless all its competitors have been sprayed out with the same
herbicide, it won't thrive," commented Dr Les Firbank, who led the
consortium of scientists on the recent UK Farm-Scale Evaluations (FSEs)
of genetically modified plants.

"There's lots of evidence for that," he told the BBC News website.


Seed collection

The study was conducted by Centre for Ecology and Hydrology (CEH) researchers.

It looked for any evidence that a genetic trait in an oilseed rape,
engineered to be resistant to a particular herbicide called Liberty,
would pass to near-relatives growing wild in the field or at the margin.

The degree to which such transfer is possible informs the debate about
superweeds, which some have claimed could upset ecological relationships
in the countryside and so harm biodiversity.

The CEH team collected more than 95,000 seeds of wild relatives in and
around the FSE trial sites and grew them up in greenhouses. These plants
were then sprayed with Liberty (a glufosinate ammonium) to see if they
had acquired herbicide tolerance - through their parents being pollinated
by the GM rape.

The scientists found just two plants, of Brassica rapa or turnip rape,
that showed resistance to the treatment; a rate of 0.000021.

But Brassica rapa is a very close relative of farmed oilseed rape and the
discovery of some gene flow is not a huge surprise, say the scientists.

The CEH team also toured fields, daubing Liberty on the tissues of weeds
and looking for the expected signs of die-back.

The researchers found just one weed - what they believe was a charlock (
Sinapis Arvensis ) - which showed no reaction to the application.

DNA analysis on a leaf sample confirmed the gene trait from the
engineered oilseed rape was present, but when the researchers returned
the following year to the same field they could find no herbicide
tolerance in seedlings of the charlocks growing there.


'Serious consequences'

Nonetheless, anti-GM group Friends of the Earth believes the existence of
just one tolerant charlock should merit major concern.

It said that if GM oilseed rape were grown commercially, herbicide-
resistant weeds could become widespread.

FoE argued that farmers would then have to use more - and more damaging -
weedkillers to get rid of them, with knock-on impacts on the environment.

"The government's trials have already shown that growing GM crops can
harm wildlife. Now we're seeing the real possibility of GM superweeds
being created, with serious consequences for farmers and the
environment," commented FoE's GM campaigner Emily Diamand.

Environment Minister Elliot Morley said: "Even if a hybrid did once
exist, it has disappeared. We do however need to improve our
understanding of all aspects of gene transfer and this means we must take
this into account with individual GM applications.

"Our top priority is to safeguard human health and the environment. There
are no trials of GM oilseed rape in the UK at the moment. No consents for
commercial cultivation in the EU have been issued and there are none in
the pipeline."

The £6m FSEs were described as the biggest ecological experiment in the
world and a model for measuring the impact of new farming techniques on
the environment.

The results for four types of engineered crops - a spring-sown oilseed
rape, a winter-sown oilseed rape, a sugar beet and a maize - were tested
over a period of three years.

All were engineered to be resistant to a particular herbicide, which
meant they would continue to prosper when the weedkiller was applied to
the "pest" plants in the field.

Only the maize came through the trials with approval because the field
management used to cultivate the bitotech crop appeared to be kinder on
wildlife than the regime employed on the conventional maize grown as a
controlled comparison.


                                  PART IV
-------------------------------- GENET-news -------------------------------

TITLE:  Weed discovery brings calls for GM ban
SOURCE: The Guardian, UK, by Paul Brown
        http://www.guardian.co.uk/uk_news/story/0,,1536010,00.html
DATE:   26 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


Weed discovery brings calls for GM ban

Britain cannot afford to take the risk of spreading genetically modified
genes to wild plants and should ban GM crops that have wild relatives in
the countryside, the former environment minister Michael Meacher said
yesterday.

Mr Meacher, who was the minister responsible for introducing the farm-
scale trials of GM crops in Britain to test their effect on the
environment, said he was shocked yesterday at research results revealed
for the first time in the Guardian.

The results showed that a related weed had picked up herbicide resistance
as a result of cross-fertilisation with GM oil-seed rape, something that
scientists had said would not happen in the countryside.

The discovery raises fears that herbicide-resistant superweeds could
develop in the British countryside if GM crops were grown commercially.

"I remember being reassured on this issue when I was minister. Now we
discover that charlock, a distant relative of GM oil-seed rape, has
acquired resistance to herbicide," he said.

"It means we just cannot afford to take the risk that GM crops will not
cross-contaminate wild plants in unpredictable and unforeseeable ways.

"If weeds are able to tolerate broad spectrum herbicides as a result of
cross-pollination it means we get into uncharted territory."

He said he had been to Canada to see the plight of farmers who had
encountered superweeds. They had been forced to spray them with heavy
duty chemicals.

"In a small island like Britain where we have many comparatively small
fields and many related species of plants, it is unrealistic to think we
could have adequate separation distances between GM crops and
conventional crops or their wild relatives."

It was impossible to see how organic and conventional farmers could be
safeguarded from cross-contamination, or how GM crops would not gradually
contaminate everything else.

Mr Meacher said French research, also highlighted by the Guardian
yesterday, which showed that one herbicide resistant weed introduced into
a crop had multiplied to 103,000 plants in four years, was "frightening".

"The safe option is to say simply that the risk of these GM crops is too
great and we will not grow them," he said.

Brian Johnson, an ecological geneticist and head of the biotechnology
group at English Nature, emphasised yesterday that the charlock was not a
superweed and did not appear to be fertile, but it was possible the GM
genes could be carried to other plants in the pollen.

The research did not analyse the pollen so "we could not be sure that the
trait was there".

Government researchers from the Centre for Ecology and Hydrology, who had
been surprised by their own findings of the transfer of a GM trait to
charlock, said follow-up research was needed.

In Canada plants had evolved from GM crops which were resistant to three
types of herbicide, which was why they had been called superweeds. The
charlock found in the UK was only resistant to one.

Pete Riley, the director of Five Year Freeze, an organisation dedicated
to preventing the commercial growing of GM crops for five years, said:
"The news that a GM herbicide-tolerant gene has moved from oil-seed rape
to charlock is very surprising - previously we were told that this was
impossible under field conditions.

"What a good job that there has been a moratorium to allow such
unexpected events to be discovered. Who knows what the next shock finding
will be?

"In our view it is high time that GM oil-seed rape was quietly put to
sleep. After these findings and the other field-scale trial results we
will be looking for the Advisory Committee on Releases to the
Environment, and ministers, to take a strong approach and ban it."


                                  PART V
-------------------------------- GENET-news -------------------------------

TITLE:  We need to move past scare stories in GM debate
SOURCE: The Scotsman, UK, by Joyce Tait
        http://news.scotsman.com/archive.cfm?id=1681512005
DATE:   26 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


We need to move past scare stories in GM debate

DEBATES about GM crops continue, refreshed from time to time by new
claims of risks or benefits, sometimes backed up by scientific evidence.
In the latest example, an announcement from the Centre for Ecology and
Hydrology in Dorset, reported yesterday, led to renewed claims that GM
crops have created a "superweed".

This idea is neither new nor surprising. I first became involved in such
discussions in the late 1980s when there were heated discussions among
scientists about whether GM crops would be fit enough to survive in the
natural environment, and whether they would be able to hybridise with
wild relatives.

Such questions are best answered by scientifically-based research and the
latest development comes from an initiative involving sixteen projects
set up by BBSRC, NERC and DEFRA, looking into Gene Flow in Plants and
Micro-organisms. Stakeholders and the wider public were consulted on the
scope of the programme before it was set up and the results were reported
back to them on the 23 June.

The "superweeds" described here have picked up genes from GM oilseed rape
that make them resistant to one or more herbicides. If this herbicide
resistance makes them fitter to survive than other members of their
species they will be able to multiply and spread widely. But this will
only happen on the farms where herbicides are used. Herbicide resistance
will not give an advantage to plants in wild areas where herbicides are
not used.

The phenomenon of resistance is everywhere, whether natural or brought on
by human activity. Humans are sometimes able to become resistant or
immune to diseases, but in the early 1900s infections killed large
numbers of children and adults. The development of chemical antibiotics
greatly reduced the death-toll of several major diseases, but also
inevitably set in train the emergence of antibiotic resistant disease
organisms. Should we have banned penicillin and streptomycin in the 1950s
in case they led to antibiotic resistance?

Insect pests in agriculture also develop resistance to the chemicals we
develop to kill them. In fact the history of the pesticide industry has
evolved around it. Insect resistance was one factor opening up new
markets for more advanced, and often less environmentally damaging,
insecticides as they emerged from the R&D cycles of the industry.

A side-benefit for the agro-chemical industry was that the new, advanced
pesticides could be sold for higher prices than the older ones which were
by that time no longer patented, justifying the expensive investment in
the development of new pesticides. However, at the same time there was
also investment in agricultural strategies to delay the onset of
resistance to insecticides, as has also been the case with antibiotics.

Resistance is thus an important driver of innovation and contributes to
the competitive advantage of companies. In natural ecosystems, including
those dominated by humans, it contributes to the competitive advantage of
all species. It is a fact of life which we regard as positive if it
occurs in a species we humans wish to protect, and negative if it occurs
in one that harms us.

How big is the problem and what should we do about it?

"Superweeds" would clearly be a problem for farmers who would find it
more difficult to control weeds using herbicides. If it was widespread it
would also be a problem for agro-biotechnology companies in that farmers
would stop buying their product. Organic farmers would presumably not
suffer if any of these weeds were to stray onto their land as their non-
chemical methods of weed control would still be effective. On
uncultivated or unmanaged land, herbicides are not used and resistance to
herbicides is not an issue - indeed the concept of a weed becomes irrelevant.

However, because GM crops have the potential to reproduce beyond our
control we should take such concerns very seriously, as the research
programme funded by the UK government has already done. The research has
so far drawn attention to several unresolved questions related to our
ability to control such "superweeds" - how frequently will the herbicide
resistance genes be transferred to other non-crop species, how fit to
survive will the hybrids be and how rapidly will they be able to spread?

So we should indeed take the potential problem of superweeds seriously,
but what should we do about it? Those opposed to GM crops use the
research results to reinforce the case for a continuing ban on the
introduction of GM crops in Europe. However, this will continue to
deprive European farmers of the undoubted benefits of GM crops at a time
when subsidies are being withdrawn and they are increasingly having to
compete in global markets. The farmers who were involved in the UK GM
crop trials would very much like to be able to continue using this
technology. It is also becoming increasingly clear from experience in
other parts of the world that some GM crops, including herbicide
resistant crops, do have environmental and human health benefits in that
they can significantly reduce the levels of pesticide use. These benefits
should be weighed against the potential risks.

We should be looking to broaden our range of approaches to dealing with
the potential, unproven hazards of new technology. We Europeans are
capable of being much cleverer than we have been so far in the context of
GM crops - there are management techniques that can contribute to
minimising negative effects; we can change the way we develop the
technology or add to the sophistication of the technology, rather than
banning it.

The debate about GM crops may rumble on but it is time it moved on to a
higher level of sophistication, rather than reinforcing tired old arguments.

· Professor Joyce Tait is director of the Innogen Centre at Edinburgh
University.

                                  PART VI
-------------------------------- GENET-news -------------------------------

TITLE:  Weeding out GM myths
SOURCE: The Guardian, letters
        http://www.guardian.co.uk/letters/story/0,,1536613,00.html
DATE:   27 Jul 2005

------------------- archive: http://www.genet-info.org/ -------------------


Weeding out GM myths

As someone who was broadly in favour of GM until reading your report
indicating that modified genes have been transferred from GM rape seed to
charlock (Weed discovery brings calls for GM ban, July 26), I have to say
this is far more worrying than it may seem. Charlock is also known as
wild mustard, and food historians and geneticists have demonstrated that
most of the green vegetables farmed in the western world (apart from
lettuce) were developed from it. This suggests that any GM vegetables in
the brassica family are vulnerable and whatever trait may be introduced
into one plant may be undesirable or even ruinous in another.
Steve Wilson
London

As the scientist quoted in your article (GM crops created superweed, say
scientists, July 25), can I clarify that I specifically said the plants
found during the research were not, in my view, "superweeds" because one
of them appeared to have non-viable seed? I neither said nor implied that
the plants found by the researchers would multiply rapidly or have a
"huge selective advantage" - quite the opposite.

I did not say "there is every reason to suppose that the GM trait could
be in the plant's pollen", but that it was just possible that the GM
trait could be carried in the pollen, and the research did not analyse
the pollen so we could not know if the trait was there, and, in any case,
pollen from hybrids might not be viable.
Dr Brian Johnson
English Nature

Michael Meacher (Indecent exposure, Society, Guardian, July 20) overlooks
a fundamental point, namely the basic reason for using pesticides.
Pesticides help farmers to protect their crops from pests, fungi and
weeds so they can provide us with an abundant supply of safe, affordable food.

They are among the most thoroughly regulated chemicals in the world. No
pesticide can be marketed unless its safety to consumers, users and the
environment has been established. Furthermore, the government can call
for a review of any product at any time. The majority of our food is
totally free of detectable residues and Dr Ian Brown, chairman of the
government's pesticide residues committee has explained that "the
positive effects of eating fresh fruit and vegetables are well-proven and
far outweigh any concern about pesticide residues".

Not only is the UK's regulatory system at the top end of international
best practice, as your article acknowledges, but the agricultural
industry is leading the way in terms of best practice on the farm.
Thousands of farmers have signed up to the voluntary initiative, a
programme of measures to minimise the environmental impact of pesticides.
There are already signs of wider environmental improvements with the
Environment Agency reporting a 23% reduction in pesticide levels in
rivers in 2003 compared with the levels for 1998-2002.
Peter Sanguinetti
Crop Protection Association

As an example of ways to misuse statistics, Michael Meacher's article
takes some beating. A 43% increase in risk of developing Parkinson's
disease is reported as a 43-fold increase. There are also errors of
epidemiology (failure to take account of age and sex distributions when
commenting on changes in mortality) and cherry-picking of data that best
support his argument. He asks why the Advisory Committee on Pesticides
does not take a more precautionary approach to possible long-term health
effects of pesticides. Perhaps the answer is that we look at the relevant
science more carefully than he does.
Prof David Coggon
Advisory Committee on Pesticides




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