The U.S. Supreme Court refused to let organic farmers and seed sellers challenge Monsanto’s patents on genetically modified seeds.

The justices on Monday left intact a federal appeals court decision that threw out a lawsuit against Monsanto, the world’s largest seed company. The lower court pointed to Monsanto’s promise not to sue farmers whose crops contain traces of Monsanto’s biotechnology products.

Monsanto has a major presence in North Carolina.

Monsanto has filed more than 140 lawsuits against farmers for planting the company’s seeds without paying royalties and settled 700 other cases without suing. In the case acted on yesterday, the farmers and seed dealers sought to take pre-emptive action to ensure they wouldn’t be sued in the event their corn, soybeans and other crops were contaminated by Monsanto seeds.

The farmers argued that Monsanto’s promise is inadequate because it applies only to contamination up to 1 percent. Monsanto, saying the farmers have no reason fear a lawsuit, urged the Supreme Court to reject the appeal without a hearing.