Stewart's Bacterial Leaf Blight

Disease Facts

Stewart’s Bacterial Leaf Blight is caused by the bacterium Pantoea stewartii.

This disease is transmitted to corn by corn flea beetles. Flea beetles carry the bacterium and introduce it into the corn when feeding.

Disease occurrence and severity can be predicting based on the temperature of the preceding winter. Warmer winters can favor increased survival and higher populations of flea beetles leading to increased severity of Stewart’s Bacterial Leaf Blight during the following growing season.

Management Strategies

The use of resistant hybrids is the key management strategy for Stewart’s bacterial leaf blight. See the Handy Bt Trait Table updated for 2023 for U.S. Corn Production from the University of Michigan for recommendations.


Young plants when infected most often wilt and die due to systemic infection.

Leaf blight associated with this disease occurs later in the growing season usually after tasseling.

Leaf blight lesions are long and linear with wavy margins (> 1 inch). These lesions will start in the upper part of the plant unlike most foliar diseases that start at the bottom of the plant.

Flea beetle feeding may be evident in the lesions.

    Diseased corn plants

    A corn plant with Stewart's Bacterial Leaf Blight

    Close up of a diseased corn leaf

    Close up of a leaf with Stewart's Bacterial Leaf Blight

    Related Links

    • Stewart's Bacterial Leaf Blight Fact Sheet (PDF)