The injunction follows a ruling last month that found USDA failed to abide by federal environmental laws when it approved the crop, developed by Monsanto and Forage Genetics, without conducting a full Environment Impact Statement. On Monday US District Court Judge Charles Breyer of the Northern District of California vacated the agency's 2005 approval of the Roundup Ready alfalfa, and ordered an immediate halt to sales of the seed, on the grounds that the genetically engineered gene could contaminate organic and conventional alfalfa. The decision follows a lawsuit brought last year by a coalition of groups led by the Center for Food Safety (CFS), who raised concerns that the biotech seed could be destructive to the environment. "We are pleased that the judge called for halt to sales of this potentially damaging crop," said Will Rostov, a senior attorney for CFS in a statement yesterday. "Roundup Ready alfalfa poses threats to farmers, to our export markets, and to the environment. We expect the USDA to abide by the law and give these harmful effects of the crop full consideration," he said. The judge's order states that farmers who have already purchased the GE seed may plant it until March 30, but that sales of the seed are immediately prohibited pending the court's decision on permanent junction relief. Before determining the scope of the final judgment, the court will consider any additional evidence provided. A hearing is scheduled for the end of April. Monsanto said it is hopeful that a "reasoned approach" will address questions about the regulatory approval process for the crop. "The extensive regulatory dossier for Roundup Ready alfalfa, combined with farmer stewardship agreements, provides a robust and responsible approach to managing the environmental questions raised by the plaintiffs in this case," said Jerry Steiner, executive vice president for Monsanto. Alfalfa is grown on over 21 million acres, and is worth $8bn per year (not including the value of final products, such as dairy), making it the country's third most valuable and fourth most widely grown crop. Alfalfa is primarily used in feed for dairy cows and beef cattle, and is also used in pork, lamb, sheep, and honey production. Consumers also eat alfalfa as sprouts in salads and other foods.