Environmental campaigners say the deal confirms their worst fears over the motives of companies seeking patents on life-forms. Greenpeace said the patent ties farmers into an agricultural system dependent on chemicals, by making it attractive for farmers to buy herbicides hand-in-hand with resistant crops. The herbicide will destroy weeds, but leave the specially engineered crop intact.
Earlier this month, the European patent office rejected an appeal by Greenpeace against the patent - the first to be granted on a herbicide-resistant plant.
Greenpeace said that the day after the patent office rejected its appeal, it was revealed that the two companies that filed the original patent, had granted Hoechst exclusive rights to exploit its weed control aspects. Hoechst makes the Basta herbicide to which the engineered crops are resistant.
The patent, filed by Plant Genetic Systems, a Belgian company, and Biogen, one of America's largest biotechnology companies, is unusually broad. It covers any crop altered to resist the Basta herbicide. Crops already tested include potatoes, sugar beet, tomatoes, oil seed rape and tobacco.
These crops have an extra foreign gene taken from a bacteria. The first commercial engineered crop is likely to be herbicide-resistant maize, already tested in trials in the United Kingdom and expected to go into production in Canada within three years.
Greenpeace said the fact that Hoechst was the main licensee would have been damaging to the case put by Plant Genetic Systems and Biogen were it made public before the appeal. 'The company will be able to sell more of its herbicide . . . When the European patent office granted the patent they promoted a technology whose future depends upon the large-scale release of genetically engineered organisms and the increased use of herbicides.'
Sue Mayer, Greenpeace's director of science, said one of its main concerns was that the altered crops would transfer their resistance to wild plants, via pollen, forcing farmers to use ever stronger herbicides, with little knowledge about their effect on the environment. The group also believes the use of such crops will make it easier for super-resistant plants to thrive.
'People's attitudes to the environment and intensive agriculture are changing. Farmers understand that we are heading for a situation where no herbicide will be useful for very long. Society is deciding against chemical and genetic pollution, so we should not reward that technology by giving it a patent,' she said.
Dr Anne-Marie Bouckaert, director of technology, planning and protection at Plant Genetic Systems, said: 'I am sad to hear that Greenpeace is persisting with its objections. I don't think it is serving its objectives with that. We should come to a dialogue instead of fighting each other in court. Their fight is nothing to do with the environment, but over economic and ethical issues.'
Greenpeace plans to take legal advice on its next step against the patent as soon as it receives the patent office's detailed reasons for turning down the group's appeal.