close up cucumber leaves affected by downy mildew

agriculture and blight closeup cubensis cucumber cucumis danger disease diseased downy farming flower food fungi fungicide fungual fungus garden gardening green growth home infection infest leaf macro microbiology microorganism mildew mold mould nature outbreak pathogen pathology peronosporoz pest plague plant plasmopara powdery problem pseudoperonospora pustules sativus spot symptoms view virus