When Swiss scientists reported earlier this year a genetically engineered strain of rice that produces beta-carotene, a source of vitamin A, it was hailed as a breakthrough that could help save the lives of an estimated 1 million to 2 million children each year in the developing world. It also came as a much-needed shot in the arm for the beleaguered agricultural biotech industry.

The growing opposition to biotech foods around the world is threatening the future of the technology. And a number of industry executives now acknowledge that the problem with first-generation products-for example, Monsanto's herbicide-resistant soybeans and insect-tolerant corn-is that while they may save farmers money and cut down on chemical use, they lack a visible payoff for the average shopper. "There may be risks with no benefit. So the consumer says 'why should I put up with it?'," says David Wheat, an industry analyst at the Bowditch Group in Boston, Mass.