UK scientists back GMO maize crop trial results

British supporters of genetically modified crops got a shot in the arm yesterday after scientists who carried out field trials said they stood by their verdict that GMO maize is less damaging to wildlife than conventional varieties.

This was despite the fact that the European Union has subsequently banned on health grounds a pesticide used in the trials, which environmentalists say are flawed as a result and should be repeated.

In a new research study, the results of which were published in scientific magazine Nature, the group of scientists behind the 1999-2003 field trials said that final weed numbers, and hence biodiversity, would still be higher in fields of gene-spliced maize.

Most of the conventional maize crops tested were sprayed with atrazine, simazine or cyanazine, collectively called triazines.

The triazines were banned by the EU in October 2003 amid doubts about their safety for human health.

"We conclude that the comparative biodiversity benefits from GM herbicide-tolerant maize cropping would be reduced, but not eliminated by the withdrawal of triazines in the UK," scientist John Perry said.

In the trials, fields sown with GMO maize produced more weeds and seeds, which in turn feed local birds, than those planted with conventional maize, the research report concluded.

Scientists in the latest study used data from the original trials to analyse the effect of different weed killer spraying regimes.

"A large reduction in weed numbers was found when atrazine was applied before the maize crop had emerged from the ground. Other patters of conventional weed killer used were less effective, but still reduced weed numbers more than the weed control practised in the GM herbicide-tolerant maize," the scientists added.

Trials into the effects of GM maize, sugar beet and rapeseed got underway in 1999.