This weakens those tissues and allows root and stalk rot pathogens to invade. Leaf diseases, insect feeding and hail reduce the leaf area available for photosynthesis. Cloudy weather reduces the sunlight available for photosynthesis. If good growing conditions during ear and kernel formation are followed by moisture stress later on, the problem is worsened. Low soil fertility.
Nutrient imbalance caused by low potassium and high nitrogen increases losses from stalk rot.
If nitrogen is available early but is lost before the end of the season, stalk rot may be increased dramatically. Insect feeding, especially corn rootworms and corn borers. These primary pests of corn provide entry ports for disease organisms. They also diminish plant function by reducing water and nutrient flow into and through the plant. Compaction, which limits normal root growth and water and nutrient uptake.