1. Diseases of Maize 1. Smut Caused by fungus: Ustilago maydis
Most widely recognized maize disease
Symptoms:
Complete barrenness in most plants
Result:
Reduced grain development
~30% yield loss

2. Appears as galls on both the ear and stalk
White at first, but develop into dark lesions with dark spores inside the whitish membrane.
Galls break and scatter spores
More likely to attack vigorous growing plants
Not poisonous to livestock and man.

3. Smut organism lives in the soil
Seed disinfection or treatment is ineffective, except to prevent spread to new fields
Treatment:
Crop rotation
Don’t spread manure infested with smut on fields.
Plant resistant varieties.

4. Control Rotate field out of maize for 2 years
Used treated seed to prevent infestation into other fields

5. 2. Leaf Blight Infection of the lower leaves
Boat-shaped, grayish lesions
Spread to other leaves in cool, damp weather
Can cause leaf death

6. Control
Plant resistant varieties.
Crop rotation.