- Weeds have become stronger and fitter by
cross-breeding with genetically modified crops, leading to fears that
superweeds which are difficult or impossible to control may invade
farms growing standard crops.
- Two separate teams, one working on sunflowers in the
US and the other on sugar beet in France, have shown weeds and GM food
crops readily swapping genes.
- In the case of wild sunflowers, classed as "weed"
varieties in America, specimens became hardier and produced 50% more
seeds if they were crossed with GM sunflowers which had been
programmed to be resistant to seed-nibbling moth lavae.
- Allison Snow, who headed the team at Ohio State
University, confessed in New Scientist that she was "shocked" by the
results. "It does not prove all GM crops are dangerous," she said. "I
just think we need to be careful because genes can be very valuable
for a weed and persist for ever once they are out there."
- Pioneer Hi-Bred, which developed the GM sunflower,
has abandoned the idea of selling the strain commercially.
- The sugar beet results show that wild and GM
varieties swapped genes, sometimes to the advantage of the wild
varieties and the detriment of the GM plants, which produced lower
yields. Writing in the Journal of Applied Ecology, the University of
Lille team said they had underestimated the likelihood of GM beets
swapping genes with the beet weeds that grow among them.
- The two sets of results add to the fears of
environmental groups and organic farmers that normal crops could be
contaminated by GM varieties - and make weeds impossible to control.
This is less of a problem in countries where crops have been
introduced, for instance soya grown the US, because no native weed
varieties exist. But in Europe, particularly in Britain, where weed
species of both beet and oil seed rape exist, the risk is potentially
- Adrian Bebb, GM campaigner at the environmental
group Friends of the Earth, said GM beet was now being grown at 16
farm-scale trial sites in England. "Once again scientists are
discovering new impacts of GM crops," he said. "The government always
emphasises the importance of a sound scientific approach to GM crop
safety, so they should look at this research seriously and question
whether or not we should be testing GM crops out of doors."
- Two years ago government research reported that GM
crops could cross-pollinate with ordinary crops over larger distances
than had been thought. The government is in its final year of trials
to investigate the effect of growing GM crops on the