Zeneca does this by genetically engineering its maize to produce an enzyme, called ribonuclease, which interferes with pollen production.

ECONOMIST: Terminator genes

Speaking at the American Chemical Society meeting in New Orleans, Miriam Sticklen of Michigan State University described her work on engineering corn stalks to contain an enzyme normally found in the stomach of cattle.

NPR: Scientists Seek New Ways to Produce Biofuel