powdery mildew of pepper

africa agent agricultural agriculture agriculturer agronomy algeria bacteria bean blight branch burn causal chlorophyll chlorose chlorosis country countryside curling destruction disease diseased downey downy etiolation feed field fongicide food fungi fungus green leaf leaves legume leveillula line mediterranean mildew mycelium natural nature necrose necrosis oidiopsis pathogen pathogens pattern pepper pesticide phytopathology plant powdery rust showing symptom taurica tissue vegetable vegetables wilting yellowing