When disease pressure is very high, more resistance may be needed. Plant breeders breed for high levels of specific resistance to certain diseases. Check with your seed company representative for information on the best seed for your situation. A summary of the types of resistance you can expect to find in common hybrids and varieties follows. Most hybrids grown in Iowa have some polygenic resistance to common foliar diseases including rust, northern leaf blight, anthracnose, gray leaf spot, and northern leaf spot.
Some hybrids are more resistant than others.
Stay-green is related to this characteristic. Single gene resistance may also be available, but is not as common. Most hybrids have some tolerance, often reported as a stalk rating or lodging percent. This measures the ability of the plant to remain standing even when infected. Resistance is available for some stalk rots, including anthracnose and4 Diplodia.