Stewarts bacterial wilt & leaf blight
Area of impact: Leaves
Description: Symptoms occur in two phases. First seedlings will have light green to yellow streaks on their leaves. Streaks run parallel to leaf veins. Seedlings may wilt and die. The second phase occurs after tasseling. Leaves will have light green or yellow streaks and infected areas will die. This disease is most common in sweet corn.
Pathogen involved: Erwinia stewartii (a bacterium)
Timing/Conditions: Overwinters in and is transmitted by the corn flea beetle so warm winters followed by high corn flea beetle populations in spring contribute to the disease. Symptoms occur during seedling stage and after tasseling.
Contributing factors: High temperatures and soil moisture and high levels of phosphorus and nitrogen in the soil.
Management practices: Plant resistant hybrids and use seed-applied insecticides.