WASHINGTON (AP) -- Supreme Court justices on Tuesday sharply questioned a lower court's decision that has prohibited biotech giant Monsanto Co. from selling genetically engineered alfalfa seeds, possibly paving the way for the company to distribute the seeds for the first time since 2007.
The case has been closely watched by environmentalists and agribusiness. A federal judge in San Francisco barred the planting of genetically engineered alfalfa nationwide until the government could adequately study the crop's potential impact on organic and conventional varieties.
St. Louis-based Monsanto is arguing that the ban was too broad and was based on the assumption that their products were harmful. Opponents of the use of genetically engineered seeds say they can contaminate conventional crops, but Monsanto says such cross-pollination is unlikely.
Organic groups and farmers exporting to Europe, where genetically modified crops are unpopular, have staunchly opposed the development of such seeds.
Environmentalists are concerned with the case's effect on a federal law that requires the government to review a product's effect on the environment before approving it. The U.S. Agriculture Department earlier approved the seeds, but courts in California and Oregon said USDA did not look hard enough at whether the seeds would eventually share their genes with other crops.
Aside from the precedent, the case may be irrelevant in another year, when the USDA is expected to finish the full environmental review that was not done in the first place. It is expected to again approve the seeds for production.
Several justices appeared skeptical that the lower court had the authority to fully ban the sale of the product because of the pending environmental review. Chief Justice John Roberts questioned why the court issued the injunction instead of simply remanding the matter back to the USDA.
Justice Antonin Scalia appeared even more wary, questioning the idea that genetically modified crops could contaminate other crops.
"This isn't the contamination of the New York City water supply," he said. "This isn't the end of the world, it really isn't."
Alfalfa, which is used for livestock feed and can be planted in spring or fall, is a major crop grown on about 22 million acres in the U.S., Monsanto said in court papers. Monsanto's alfalfa is made from genetic material from bacteria that makes the crop resistant to the popular weed killer Roundup.
Justice Stephen Breyer did not taking part in the case because his brother, U.S. District Judge Charles Breyer in San Francisco, issued the initial ruling against Monsanto.
A decision is expected before late June. The case is Monsanto v. Geerston Seed Farms, 09-475.