<P> The production of corn (Zea mays mays, also known as "maize") plays a major role in the economy of the United States . The country is the largest producer of corn in the world, with 96,000,000 acres (39,000,000 ha) of land reserved for corn production . Corn growth is dominated by west / north central Iowa and east central Illinois . Approximately 13% of its annual yield is exported . </P> <P> Corn spread across North America a few thousand years ago . The original corn plant known as teosinte is still grown in Mexico . Newer varieties are much larger, due to plant breeding efforts of Native Americans and scientific research . It is now the third leading grain crop in the world . </P>

Where does the us rank in corn production