- Sunscald occurs when the rate of water movement up to and through the leaf cells cannot keep up with the rate of evapotranspiration from these leaf cells.
- Younger leaves and leaves with direct orientation to the sun are most affected.
- Tissue can have a silver/gray cast initially and then turn brown and necrotic in a few days.
- If no additional disease is present, stalk tissue will look normal.
- Sunscald damage will not progress on the leaves.
- Injury can occur while leaves are still in the whorl.
- Water in the form of dew or from irrigation can injure tissue as high temperatures heat water on the leaf surface.
- Injury to the tassel can occur, but typically will not decrease pollination as damage is usually isolated within the field.
- Susceptibility to sunscald differs by hybrid genetics.
Closeup of sunscald injury on a corn leaf, showing injured tissue between the leaf veins.
Sunscald injury to a corn leaf tip.
Severe sunscald injury throughout the corn canopy.