For example, DNA Plant Technology Corp. is working to develop herbicide and pest-resistant strawberries, a fruit native to the United States. Before it makes the plants available to farmers, the company will carefully evaluate whether the new genes give the strawberries growth advantages, said Thenell. It will also test what happens if cross-breeding introduces the genes into related species of strawberries. Should the studies prove the new plants unsafe, DNA Plant Technology won't market them to farmers, said Thenell. Ellstrand said that while he doesn't oppose biotechnology, he's concerned that the plants are being introduced before enough is known about them.
Farmers say the products make their land more productive and have environmental benefits.
They say the plants make farming easier. They also allow them to use less water, grow more of a given crop and limit runoff from herbicides and pesticides. But Ellstrand worries about bioengineered plants coming into contact with native relatives in the wild. Twelve of the 13 major crop species in the world already mate with wild varieties. There's some evidence that cross pollination between crops and their native relatives have produced hardier varieties, said Ellstrand.