The Knowledge Centre

European Union rules forbid them to import gene-spliced maize, but do allow them to buy GMO soya beans and meal from the United States or Argentina.

Farmers' representatives said they would also welcome the chance to grow maize with higher yields promised by GMO makers, but which may neither be imported nor planted in Europe.

"Either GMOs are good or bad, but they tell us we can import them (soya) but not grow them (maize)," Agustin Marine, of the Spanish Maize Producers' Association, told the Lisbon conference.