SPOKANE, Wash. (AP) — Alfalfa seed and plant samples taken from an eastern Washington farm contain a low level of genetic modification, even though the farmer reportedly did not want to grow such crops, the state’s department of agriculture announced.

The agency said the samples showed a low-level presence of a genetic trait called Roundup Ready, meaning they are able to tolerate the well-known herbicide. The tests did not reveal the percentage of Roundup Ready presence in the samples.

The testing was ordered after a hay farmer who intended to grow alfalfa that was not genetically modified had his crop rejected by a broker who found evidence of genetically modified pesticide resistance.

“This is the end of the process for the Washington state Department of Agriculture,” said Mike Louisell, a spokesman for the agency.

The results were shared with the farmer and with the U.S. Department of Agriculture, he said. The federal agency will make its own decision on whether to take any action in the case, he said.

The name of the farmer has not been released.

Roundup Ready alfalfa, used as animal feed, has been approved by the federal government and is grown for both the domestic and export markets, the state said.

“There is strong market demand for Roundup Ready alfalfa and conventional alfalfa varieties,” the state agency said in a press release.

The samples were tested at the agency’s lab in Yakima, Wash.

State Sen. Maralyn Chase, D-Shoreline, said the incident shows the dangers of genetically modified crops.

“Our state’s farmers are becoming collateral damage to the reckless practices of the agriculture industry in this country,” Chase said. “More than 60 of our trade partners throughout the world have bans on the import of unlabeled GMO foods.”

Genetically modified alfalfa is legal to grow and sell in the U.S. That makes this incident different from May’s discovery of genetically modified wheat in an Oregon field. Modified wheat is illegal in the U.S. outside of licensed test fields.

Consumers have shown increasing interest in avoiding genetically modified foods, so it has been important to separate them from products that are unmodified.

After the broker discovered the alfalfa was genetically modified, the farmer contacted the state agriculture department in late August, and tests began after Labor Day, Louisell said.

Pesticide-resistant alfalfa was developed by Monsanto Co. and has been licensed to several companies.

Monsanto spokesman Thomas Helscher said that major importers of U.S. alfalfa, including the United Arab Emirates, Japan and South Korea, have no restrictions on genetically modified crops, and negotiations with China over imports of modified alfalfa are ongoing.

A group in Washington calling for more rigorous food labeling said the incident shows the need for more scrutiny.

“This really does go to show that some of our trading partners are sensitive to genetically engineered crops,” said Elizabeth Larter, spokeswoman for the Yes on 522 campaign, which is pushing a fall ballot measure that calls for labeling at the seed level.

Genetic modification can be as simple as identifying desirable traits in a plant and breeding them into a crop, sometimes forming a new species.

What many markets fear, particularly Europe and parts of Asia, is the impact of recombinant DNA on the human body in ways we haven’t yet understood. That includes the potential for desirable traits in one species to transfer to another species, where the trait would be harmful.

This is true of herbicide-resistant wheat and alfalfa. If such herbicide resistance were accidentally to slip into the DNA of a weed, for instance, it could form a superweed, impossible to kill with modern methods.

Copyright 2013 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.