WASHINGTON (AP) _ The Supreme Court has sustained Monsanto Co.’s claim that an Indiana farmer violated the company’s patents on soybean seeds that are resistant to its weed-killer.
 
  The justices, in a unanimous vote Monday, 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.
 
  Justice Elena Kagan says a farmer who buys patented seeds must have the patent holder’s permission.
 
  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.