On Jun. 21, 2010, In its first ruling on genetically engineered crops, the Supreme Court today overturned a lower court’s decision prohibiting Monsanto Co. from selling pesticide-resistant alfalfa seeds until the government completes an environmental impact study.

“An injunction is a drastic and extraordinary remedy, which should not be granted as a matter of course,” Justice Samuel Alito wrote for the 7-1 majority.

A U.S. District Court in San Francisco “abused its discretion” in 2007 when it ruled that the government needed to examine the modified breed’s environmental impact, Alito wrote.

“The District Court abused its discretion in enjoining APHIS [the Agriculture Department’s Animal and Plant Health Inspection Service] from effecting a partial deregulation and in prohibiting the possibility of planting in accordance with the terms of such a deregulation,” the justice argued.

Environmental groups, farmers and consumers sued USDA in 2006 to force it to rescind its 2005 approval of the Monsanto seed until it conducted a full environmental impact study. Monsanto intervened on the government’s side in the suit.

The groups argued that cross-pollination of genetically modified crops could contaminate conventional alfalfa fields and that overuse of the herbicide Roundup, which the seeds were bred to resist, could harm soil and groundwater or give rise to Roundup-resistant “super weeds.”

U.S. District Court Judge Charles Breyer, brother of Supreme Court Justice Stephen Breyer, ruled in 2007 that USDA’s study failed to address those concerns.