KANSAS CITY, Missouri (Reuters) - A federal judge on Tuesday ordered the destruction of plantings of genetically modified sugar beets developed by Monsanto Co after ruling previously the U.S. Agriculture Department illegally approved the biotech crop.

U.S. District Court Judge Jeffrey White in August banned the planting and sales of Monsanto’s “Roundup Ready” biotech sugar beets after determining that their approval in 2005 by the USDA was illegal. He said the government must conduct a thorough environmental review before approving the crop to comply with the law.

But shortly after the ruling, the USDA issued permits allowing companies to plant seedlings to produce seed for future GMO sugar beet crops.

In his ruling Tuesday Judge White said those seedlings “shall be removed from the ground.”

Earthjustice, a consumer group that brought the case against the USDA and had asked the judge to order the young plants be destroyed, said the action was the first court-ordered destruction of a GMO crop.

“We had to run into court and ask the judge to stop them,” said Earthjustice attorney Paul Achitoff. “He said you’ve got to tear up the plants, which was what we asked him to do. It’s an extreme sort of a thing ... but the circumstances were such that there really wasn’t any alternative. They basically had dared the court to stop them.”

Sugar beets account for more than half of the nation’s sugar supply, and Monsanto’s Roundup Ready beets have been popular with farmers as they have been genetically altered to withstand sprayings of the chemical herbicide Roundup, making weed management easier for producers.

But environmentalists say widespread use of the crop leads to increased use of herbicides, proliferation of herbicide resistant weeds, and contamination of conventional and organic crops.

Monsanto, which owns intellectual property rights to the sugar beet technology, sought to intervene in the case, and was granted limited standing. But the company had no immediate comment on Tuesday.

In previous court filings Monsanto said revoking the government’s approval of its genetically modified seed could cost the company and its customers some $2 billion in 2011 and 2012.

Along with Monsanto, others in the industry sought to intervene, saying they needed at least limited planting permits for research and development, basic seed production and to preserve the ability to create genetically engineered commercial seed varieties to meet potential future demand if production is ultimately authorized.

USDA officials could not be reached for comment.

Earlier this month, the USDA issued a draft proposal for handling of the GMO beets. It said it was considering allowing Monsanto beets back in the fields by next year under a permit subject to conditions “to prevent any potential plant pest risks.”

The USDA gave the green light to Monsanto’s GMO beets in 2005.

Plaintiffs in the case include the Center for Food Safety, Organic Seed Alliance, High Mowing Organic Seeds and the Sierra Club.