Corn farmers from four Midwestern states filed class action lawsuits against leading agritech company Syngenta, alleging significant economic losses stemming from its genetically modified corn. The farmers, including many with large family holdings, claim they suffered huge losses from Syngenta’s premature release of genetically engineered MIR162 corn seed into the U.S. market, before the seed was approved by China, a key corn importer.

The four separate federal lawsuits contend that marketing of MIR162 corn — also known as Agrisure Viptera — by Syngenta in the United States has caused domestic corn to be effectively excluded from China and U.S. corn prices to be detrimentally impacted as a result. Since November 2013, China has stopped importing U.S. corn upon detection of the genetically engineered seed in shipments. China, which was previously the third-largest export market for U.S. corn, has not indicated whether it will approve Syngenta’s MIR162 corn and resume imports.

The suits were filed on Oct. 3 by farmers in Illinois, Iowa, Missouri, and Nebraska. Last month, grain exporter Cargill also sued Syngenta over losses stemming from China's rejection of genetically modified corn.