Fungal disease
Corn (Maize) Gray Leaf Spot
Also known as Cercospora leaf spot
A fungal disease of maize that causes long, rectangular grey or tan lesions between the leaf veins.
Symptoms
- Narrow, rectangular grey to tan lesions running parallel to the veins
- Lesions merging until whole leaves die back
- Damage starting on lower leaves and moving up the plant
What causes it
The fungus survives in maize residue and spreads in warm, humid weather with long periods of leaf wetness.
What you can do
- Do not grow the same crop in the same spot next year; rotate beds for two to three years.
- Remove or dig in old maize residue after harvest.
- Choose resistant varieties.
- Give the plant space and good air flow; avoid crowding it against other plants.
Not sure it's gray leaf spot?
Photograph one affected leaf and Plantulus will suggest the most likely problem, with a confidence score. It's free and needs no sign-up.
Check a leaf photoOther corn (maize) problems
General guidance only, not a diagnosis. Check product labels and local rules before using any treatment, and ask a horticultural specialist if a valuable plant is struggling. See the disclaimer.