The Department of Agriculture said on Friday that American farmers could resume growing genetically engineered sugar beets that had been barred by a federal judge.

The decision could allow farmers to plant the biotech seeds this spring, avoiding a possible shortage of sugar later on.

“The decision is a win for consumers,” said Duane Grant, a beet farmer in Rupert, Idaho, and chairman of the farmer-owned Snake River Sugar Company. “It assures a full beet crop will be planted in 2011.”

But environmental groups and organic farmers were dismayed by the decision.

The genetically engineered beets accounted for more than 90 percent of the sugar beets grown last year. They can withstand spraying by the herbicide Roundup, allowing farmers to kill weeds without harming the crop.

But in August, in response to a lawsuit filed by environmental groups and organic farmers, a federal district court judge in San Francisco revoked the approval of the beets.

The judge, Jeffrey S. White, said the Agriculture Department had to prepare an environmental impact statement assessing the effects of the biotech crop. His biggest concern was that the genetically engineered trait could spread to organic sugar beet crops or to other crops like Swiss chard and red table beets.

But some farmers said there might not be enough nonengineered seed available to satisfy demand. The government projected a possible 20 percent reduction in American sugar production.

As a result, the Agriculture Department was under pressure to allow the genetically engineered beets to be grown – and to do so in time for the spring planting season – even though it did not expect to finish the environmental impact statement until May 2012.

The solution announced Friday was an interim “partial deregulation” of the beets that will hold until the impact statement is done and a final decision made. The partial deregulation was requested by the two companies that developed the crop, Monsanto and KWS, a German seed company.

Farmer-owned sugar processing companies will enter into compliance agreements with the government covering their growers. The agreements will spell out the measures that must be taken to prevent the genetically engineered traits from spreading. Farmers’ fields will be subject to inspection.