Resistance to various diseases is available in many corn hybrids and varieties of soybean and wheat. Use of resistant varieties should be a major part of a disease management program. No variety is resistant to all diseases, so it is important to choose a variety with resistance to diseases that have a history of occurrence in a field or region. Toward some diseases, resistance is only partial. It is important to ask seed dealers what degree of resistance a variety possesses and whether the resistance is effective against prevalent strains or races of the pathogen.
Weather is the big uncertainty for all diseases of corn, soybean, and wheat.
If weather is not favorable for a particular disease, it will not develop even if the variety is susceptible and the pathogen is present in or near a field. Each disease responds somewhat differently to weather, and we cannot predict what next spring and summer will bring. Using a combination of appropriate cultural practices and disease resistant varieties can help reduce the risk of loss in yield and grain quality from disease should weather conditions be favorable for one or more diseases.