Fungal disease
Corn (Maize) Northern Leaf Blight
A fungal disease of maize that causes long, cigar-shaped grey-green to tan lesions on the leaves.
Symptoms
- Long, cigar-shaped lesions, grey-green at first, then tan
- Lesions starting on lower leaves and moving upward
- Large areas of dead leaf in wet seasons
What causes it
The fungus survives in maize residue and spreads in moderate temperatures with heavy dew or rain.
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 maize residue after harvest.
- Choose resistant varieties.
Not sure it's northern leaf blight?
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.