The modified seeds were developed by Monsanto to be tolerant of glyphosate, the active ingredient in the herbicide Roundup, also a Monsanto product and used to control weeds in fields where alfalfa is grown.
The non-profit Center for Food Safety has sued both the U.S. Department of Agriculture and Monsanto several times over the deregulation and use of the genetically modified seeds, known as Roundup Ready Alfalfa or RRA.
Increased use of Roundup herbicide would cause weeds to adapt and become Roundup-tolerant, and genetically modified RRA could change the genetic structure of other alfalfa varieties, the group claimed.
U.S. District Judge Samuel Conte dismissed the case, citing "prevailing statutory and regulatory framework" and other rulings, Courthouse News reported.
"[USDA] is not the legally relevant cause of the glyphosate use complained of by plaintiffs," and it "has no authority to regulate where and how glyphosate is used. Congress has delegated that authority to EPA ... and EPA has registered glyphosate for use on RRA," Conte wrote.
"However, the court is in no position to evaluate EPA's compliance with relevant environmental laws."