GM crops need more pesticide

Last edited 3 December 2003 at 9:00am

Biotech companies have continually promised that genetically modified (GM) crops will benefit the environment. But now the countryside in the United States is suffering because of the rush to embrace GM.

A new study has revealed that pesticide use has increased by a massive 73 million pounds (33,112 metric tonnes) since US farmers started to grow GM crops commercially in 1996.

The report compared the average weight per acre of pesticides used on GM crops to the weight used on conventional crops. The 73 million pound difference between the two is primarily due to the introduction of Herbicide Tolerant (HT) crops, particularly GM soya.

These crops are genetically modified to be resistant to a particular pesticide, allowing it to be used indiscriminately to kill pests. But many farmers then have to spray greater quantities of herbicide on their GM crops, as weed species adapt to GM and become harder to control. In some cases, the weeds are even developing a genetic resistance to the herbicide.

The report did find a modest reduction (of between 2 - 2.5 million pounds per year) in the use of herbicide use for a type of GM cotton - a gain far outweighed by the massive increases reported for other GM crops.

Required reading for Tony Blair
The UK Prime Minister is currently deciding whether or not to commercialise GM crops. Greenpeace campaigner Ben Ayliffe said the report "will make sober reading for Tony Blair as he reflects on which way Britain should jump."

Earlier this year the results of farm-scale evaluations on GM crops grown at test sights across Britain revealed the detrimental effect that GM technology would have on the British environment.

More information
The comprehensive US study was released by the Northwest Science and Environmental Policy Centre and is available for download at here.

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