PESTICIDE USE on GM crops in the USA has increased sharply after an initial drop during the first three years of cultivation, a new study has revealed. The amount of agrochemicals applied to GM crops has been rising year-on-year for the past five years – a total increase of 55,000 tonnes since 1996.

The study, conducted by Charles Benbrook, a former executive director of the Board of Agriculture at the US National Academy of Science, concludes that the biotech industry’s claims that GM crops help reduce the use of pesticides are unfounded. While the use of agrochemicals on Bt crops modified to be toxic to insects has dropped, it has increased significantly on herbicide-tolerant crops, mainly because of the spread of tolerant weeds.

Gundula Azeez, the Soil Association’s policy manager, said: “GM crops would inevitably lead to more chemicals in British farming. Regrettably, the government’s farm-scale trials only tested the impact of GM crops in the first year. But the new US study shows that the negative impacts get worse year-on-year.”