A farmer in Washington state found GMO wheat that hasn’t been approved by federal regulators growing in a field that had not been planted since 2015, according to a Reuters article.

The farmer found 22 unapproved GMO wheat plants. The wheat was developed by Monsanto.

Related: Monsanto settles with farmers on 2013 GMO wheat discovery

There is no commercially approved GMO wheat and the grain hasn’t been traced to commercial supplies, according to USDA.

In response to the finding, South Korea said it will step up quarantine measures for U.S. milling and feed wheat, according to SRNNews.com.

Related: Lawsuits sprout from Oregon GMO wheat discovery