Pro- and anti-GM campaigners have clashed over the relative performance of genetically modified crops.

On the day that new figures came out demonstrating another year of growth in the global GM area, green lobby group Friends of the Earth issued its own report claiming the new technology had led to a massive increase in pesticide use and failed to boost yields.

"GM crops have failed to deliver the long-promised benefits of the biotech industry," said FoE GMO co-ordinator Nnimmo Bassey. "Instead, increased pesticide use caused by these crops threatens the environment and communities around the world."

To back up the claim, FoE points to data from the US department of agriculture showing a 15-fold increase in the use of the herbicide RoundUp from 1995 to 2005. Brazil had seen an 80% increase from 2000-2005.

"This is resulting in increasing numbers of glyphosate-resistant weeds around the world, leading to higher production costs for farmers as well as concerns about the environmental impact," said FoE.

The lobby group also attacked GM technology for failing to alleviate world poverty.

"The biotech industry tells Africans that we need GM crops to tackle the food needs of our population," said Mr Bassey. "But the majority of GM crops are used to feed animals in rich countries, to produce damaging biofuels, and don't even yield more than conventional crops."

But these claims have been rebuffed by the biotech industry, which has described FoE's report as "inaccurate" and "not based on peer-reviewed scientific research".

According to biotechnology consultants PG Economics, pesticide use has dropped by 7% over the past 10 years of GM crop cultivation. "These reductions, coupled with the switch to more benign herbicides, have delivered significant net environmental gains," it said.

GM crops had also helped the switch to min-till methods of farming, leading to significant reductions in CO2 emissions, equivalent to taking 4m cars off the road.

According to the International Service for the Acquisition of Agri-biotech Applications (ISAAA), GM technology has had a significant benefit in third world countries. For example, cotton yields in India and China have increased by 50% and 10% respectively, with resulted gains in farmer income.