GENET archive


RISK ASSESSMENT: Two unsprayed rows mitigate effect of GMHT sugarbeet on bird populations

                                 PART I
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TITLE:  Changes to pesticide spraying could reduce GM harm
SOURCE: Nature, UK
AUTHOR: Michael Hopkin
DATE:   18.04.2007

Changes to pesticide spraying could reduce GM harm

Leaving just 2% of transgenic crop rows unsprayed could boost diversity.

British crop researchers are claiming that they have developed a method
to stop transgenic crops from damaging the biodiversity of weeds and
seeds. By leaving two rows in every 100 unsprayed with pesticides,
enough diversity can be preserved to prevent knock-on effects on birds
and other animals, they calculate.

The method could help farmers to reap the economic benefits of planting
herbicide-resistant crops while avoiding the environmental damage of
blanket pesticide spraying, say researchers led by John Pidgeon of
Broom's Barn Research Station in Bury St Edmunds, UK.

Farmers typically spray pesticide on their crops using a multi-jet boom
sprayer up to 24 metres wide. "All they would have to do is turn off the
outside two nozzles," says Pidgeon.

This reduction would allow weeds to produce seeds in the unsprayed rows,
preserving plant diversity and giving birds and insects a source of
food, Pidgeon and his colleagues say in a paper published online by
Proceedings of the Royal Society B1.

Obvious idea

The researchers undertook their work after the UK government's Farm
Scale Evaluations (FSE) reported in 2003 that herbicide-tolerant sugar
beet and oilseed rape can damage biodiversity because of the vigorous
pesticide regimes used to manage these crops.

Pidgeon is surprised that the idea of leaving some rows unsprayed has
never been evaluated before. "It occurred to me about four seconds after
the [FSE] results were published -- it is desperately obvious," he says.

They haven't yet tested the idea of leaving small strips of cropland
untouched by pesticide. Instead, they extrapolated from the FSE
experimental results for sprayed and unsprayed fields to see how much
needed to be left alone to encourage biodiversity. Leaving 2% of the
crop untouched should allow weed seeds to grow; leaving 4% unsprayed
allows weed plants to flourish, they predict.

Although genetically-modified herbicide-tolerant (GMHT) crops are grown
throughout the United States, they will not be approved in Europe unless
seed producers such as the US giant Monsanto can show that their strains
will not harm the environment any more than conventional ones do. This
makes it surprising that they have not yet tested the beneficial effects
of leaving rows unsprayed, says Pidgeon's co-author Joe Perry.

Such a proof of principle could be carried out in just one growing
season and could even be done with non-genetically-modified test
strains, he adds.


Whether the practice can be enforced, however, remains unclear. "Will
farmers do it, and how do you tell they have really done it?" asks
Matthew Heard, an ecologist at the Centre for Ecology and Hydrology in
Huntingdon, UK. "Farmers just want to maximize yields." Losing some of
the unsprayed 2% to weeds might not seem to them like a good deal.

Pidgeon claims that his technique will allow farmers to boost their
profits -- GMHT sugar beet is thought to be worth an extra 150 ($299)
per hectare than conventional varieties -- and completely avoids the
damage to weed and seed diversity. "If you leave 2% unsprayed, GMHT
sugar beet is actually better for the environment [than normal sugar
beet]," he says. "It's a win-win: economically and environmentally."

Nevertheless, "there are weeds and there are weeds", warns Les Firbank,
a researcher at the Institute of Grassland and Environmental Research in
Okehampton, UK. Some pests, such as black grass, are devastating to crop
yields while not really providing much benefit to wildlife. Farmers
would much prefer to find subtle ways to encourage broadleaved weeds.

Heard argues that restoring British biodiversity will take more than the
"gimmicky" idea of leaving rows untreated with pesticide. Decades of
intensive agriculture have already damaged wildlife; farmers should be
trying to fix this previous damage by leaving wider margins around their
fields, he says. "What we want to do is reverse these disastrous
historical impacts," he says.


Pidgeon J. D., May M. J., Perry J. N. & Poppy G. M. Proc. R. Soc. B, doi:
10.1098/rspb.2007.0401 (2007).

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                                 PART II
------------------------------- GENET-news -------------------------------
TITLE:  Two unsprayed rows mitigate effect of GMHT sugar beet on bird
SOURCE: Farmers Guardian, UK
DATE:   20.04.2007

Two unsprayed rows mitigate effect of GMHT sugar beet on bird populations

LEAVING two rows of sugar beet in every 100 unsprayed would mitigate any
adverse effects of genetically-modified herbicide-tolerant sugar beet on
food for farmland birds, according to research conducted at Broom's Barn.

The Government's Farm Scale Evaluation (FSE) trials of GM herbicide
tolerant sugar beet showed that the technology could potentially have an
adverse impact on food for farmland birds if a 'weed-free' management
approach was adopted.

However, new research, published in the Proceedings of the Royal
Society, demonstrates that leaving two crop rows in every 100 unsprayed
presents a cheap and simple approach to avoiding any adverse impacts on
bird populations.

According to research team leader Dr John Pidgeon the economic benefits
for the farming sector are large.

"This demonstrates beyond reasonable doubt that GMHT beet can be
economically and environmentally beneficial. It's a win:win situation
for sustainable agriculture," he said.

Leaving two rows in every 100 unsprayed would result in the same number
and spectrum of weeds - including valuable bird feed sources such as fat
hen - as were found in the conventional FSE beet crop trials.

Yields from GMHT beet would still be higher than conventional beet even
if two per cent of the crop were left unsprayed, added Dr Pidgeon.

"But the wider issue is that such simple ways forward were not found
during the unhelpfully polarised GM debate" he added. "UK and European
agriculture needs economically beneficial change to be introduced with
due environmental precaution. We now have the methodologies to achieve
this, with transparent, rigorous scrutiny. We need to move forward
pragmatically, on the basis of evidence and not remain trapped in
irrational thinking that prevents progress".

The new study, based on data collected during the four-year FSE, follows
on from work at Broom's Barn research station (part of Rothamsted
Research) in Suffolk that demonstrated that innovative crop management
practices deploying GM herbicide tolerant beet had the potential to
deliver food for farmland birds in spring or autumn.

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