Disease Directory

    Bacterial Leaf Spot

    Xanthomonas campestris, Pseudomonas syringae

    Bacteria
    Leaves
    Fruit

    Overview

    A group of bacterial diseases causing water-soaked spots on leaves that may become necrotic. Common on peppers, tomatoes, and many ornamental plants.

    Symptoms

    Small, water-soaked spots on leaves that enlarge and become brown or black with yellow halos. Spots may coalesce into large necrotic areas. Premature defoliation. Fruit spots on peppers and tomatoes.

    Environmental Conditions

    Humid

    Prevention

    Use disease-free seed and transplants. Rotate crops. Avoid overhead irrigation. Ensure good air circulation. Copper sprays as preventive measure.

    Management

    Apply copper-based bactericides. Remove infected leaves. Avoid working with wet plants. Improve air circulation. No cure once systemically infected.