China’s recent approval of Syngenta’s Viptera corn doesn’t mean the end of legal challenges against the biotech hybrid.

Sixteen Iowa growers and businesses filed a lawsuit last week seeking damages from Syngenta, claiming they suffered financial losses from China’s rejection of corn shipments containing Viptera corn.

The lawsuits were filed in U.S. District Court for the Southern District of Iowa on behalf of farmers in several Iowa counties, including Cass, Pottawattamie,...