Today, almost all the corn grown in America is genetically modified — 92% according to the USDA. What are those genetic modifications? We don’t know; the companies that hold those patents want to keep it secret.

Keeping that information secret prevents them from facing competition when their patents expire. Four companies control more than half of the world’s commercial seed market. Just two firms — Bayer and Corteva Agriscience — control 85% of the intellectual property covering corn in the U.S.