Plant breeders specifically breed for resistance to certain diseases, and high levels of resistance are available for these diseases. Check with your seed company representative for specific information on the seed you buy. A brief summary of the types of resistance you can expect to find in common hybrids and varieties follows. Gray leaf spot of corn Resistance is polygenic. Most hybrids do not have a high level of resistance, but in recent years, some moderately resistant hybrids have become available.
Most seed companies publish gray leaf spot ratings for their hybrids.
Both single-gene and polygenic resistance are available, but the polygenic type is more common. There are many hybrids available with good resistance to northern leaf blight, and most seed companies publish ratings. Eyespot of corn Resistance is polygenic. Most hybrids do not have a high level of resistance, but in recent years, some moderately resistant hybrids have become available. Some seed companies publish eyespot ratings for their hybrids.