Leaf Scald in Sweet Corn

Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu

Leaf scald has been found in some sweet corn crops recently. Leaf scald is a physiological disorder similar to necrotic sunburn in fruits and vegetables. It occurs when leaf temperatures rise above a critical level and cells die rapidly, leaving a bleached white appearance. While newly emerged leaves in the upper canopy of susceptible varieties that are the most exposed are the most likely to scald, some of the leaf scald can progress deeper into the canopy showing up on some of the corn husks, which will affect marketability. Leaf scald occurs most commonly when temperatures are in the high 90s or over 100, skies are clear (high solar radiation), and humidity is low. While effect on yield is usually minimal, leaf scorch at the ear leaf level can affect kernel fill.

Leaf scald has a genetic component as certain varieties of sweet corn are more susceptible. Overhead irrigation during high temperature hours can reduce this disorder.

Leaf Scald in sweet corn affecting the upper canopy.

Leaf scald affecting sweet corn husks.