The first of tens of thousands of U.S. lawsuits over Swiss agribusiness giant Syngenta's introduction of a genetically engineered corn seed variety is underway in a Kansas federal courtroom.

The trial that began Monday in Kansas City, Kansas, involves four Kansas farmers representing about 7,300 farmers in the state. Another trial involving about 60,000 cases begins next month in Minnesota.

The lawsuits allege Syngenta introduced the seed variety to the U.S. market before China approved it for imports, wrecking an increasingly important export market for U.S. corn and causing price drops.

Syngenta denies it caused losses.

The Kansas trial is the first test case. It and the Minnesota trial will provide guidance for how the complex web of litigation in state and could be resolved.