Corn Genotypes & Isolation

When planting multiple corn varieties, it’s important to understand how cross-pollination can affect kernel quality. In most cases, cross-pollination is not an issue within the same genotype group.

However, if different genotype groups pollinate at the same time, the resulting ears may develop tough, starchy kernels instead of the tender sweetness you were expecting. The best way to prevent this is through isolation.

• One option is to plant varieties 2–3 weeks earlier or later than neighboring corn so that tasseling and pollination happen at different times. Be sure to consider maturity days and tasseling days carefully. For example, planting a shorter-season corn two weeks after a longer-season corn could still result in both varieties tasseling at the same time.

• Another option is distance isolation. Plant sweet corn 600–1,000 feet away from other corn to help prevent unwanted cross-pollination.

If you plan to save seed, keep in mind that cross-pollination becomes an issue even within the same genotype group.

All varieties of popcorn, field corn, and dent corn should also be separated.