WASHINGTON — The Supreme Court said Monday an Indiana farmer violated Monsanto Co.’s patents on soybean seeds resistant to its weed-killer by growing the beans without buying new seeds from the corporation.

The justices unanimously rejected the farmer’s argument that cheap soybeans he bought from a grain elevator are not covered by the Monsanto patents, even though most of them also were genetically modified to resist the company’s Roundup herbicide.

While Monsanto won this case, the court refused to make a sweeping decision that would cover other self-replicating technologies like DNA molecules and nanotechnologies, leaving that for another day. Businesses and researchers had been closely watching this case in hopes of getting guidance on patents, but Justice Elena Kagan said the court’s holding Monday only ‘‘addresses the situation before us.’’


In a statement, Monsanto officials said they were pleased with the ruling.

‘‘The court’s ruling today ensures that longstanding principles of patent law apply to breakthrough 21st-century technologies that are central to meeting the growing demands of our planet and its people,’’ said David F. Snively, Monsanto’s top lawyer.

In the case, Vernon Hugh Bowman bought expensive, patented Monsanto’s ‘‘Roundup Ready’’ seeds for his main crop of soybeans but decided to look for something cheaper for a risky, late-season soybean planting. He went to a grain elevator that held soybeans it typically sells for feed, milling, and other uses, but not as seed.

Bowman reasoned that most of those soybeans also would be resistant to weed killers, as they initially came from herbicide-resistant seeds too. He was right, and he bought soybeans from the grain elevator and planted them over eight years. In 2007, Monsanto sued and won an $84,456 judgment.

Monsanto has a policy to protect its investment in seed development that prohibits farmers from saving or reusing the seeds once the crop is grown. Farmers must buy new seeds every year.


About 90 percent of American soybean farms use Monsanto’s seeds.

Bowman’s lawyers argued that Monsanto’s patent rights stopped with the sale of the first crop of beans.

Kagan disagreed. ‘‘Bowman planted Monsanto’s patented soybeans solely to make and market replicas of them, thus depriving the company of the reward patent law provides for the sale of each article,’’ she said. ‘‘Patent exhaustion provides no haven for such conduct.’’

Bowman also said he should not be liable, in part, because soybeans naturally sprout when planted. Kagan said the court did not buy that argument. ‘‘We think the blame-the-bean defense tough to credit,’’ she said.

Andrew Kimbrell, executive director of Center for Food Safety, said the ruling was wrong. ‘‘The court chose to protect Monsanto over farmers,’’ Kimbrell said.