Corn diseases such as Gray Leaf Spot and Northern Corn Leaf Blight will began to appear late in the season. Diseases will occur when a pathogen comes in to contact with the right host crop under favorable environmental conditions. The pathogen, host, and environmental conditions make up the disease triangle; all three must be present for disease to occur.
How does the disease triangle apply to corn?
Hybrid Sensitivity to Diseases
- Some hybrids are more susceptible to diseases than others
- Know your hybrid sensitivity to particular diseases
- Even resistant hybrids can be infected under favorable conditions
- Fungal diseases can survive the winter in crop residue from previous seasons
- Not rotating crops can increase the chance of disease in corn on corn fields, especially if disease was present the previous season
- The success of fungal disease greatly depends on the weather conditions
- Cool, rainy, humid, overcast and/or foggy conditions typically favor increase the chance of disease
- High winds, hail or other conditions that cause physical damage to the plant also increase chance of disease infection