FARMERS who embrace genetically modified crops will become slaves to biotechnology companies, the vice-president of Canada’s National Farmers Union has warned Australia’s agricultural sector. Terry Boehm, a canola grower who is on a four-state speaking tour, said the introduction of genetically modified canola in his homeland more than a decade ago had impoverished farmers and led to an exodus from the land. Biotechnology companies charged farmers a very high price, he said, and switching to GM had cost Canada its European market.