hollyhock rust, puccinia malvacearum, pustules on the flower bud

agriculture and biology chlorosis closeup control danger disease diseased farming flower fungi fungicide fungual fungus garden gardening green grow hollyhock home infection infest leaf macro mallow malva malvaceae malvacearum microorganism mold mould nature necrosis nursery parasite pathogen pathology pest pesticide phytopathology plague plant problem protection puccinia pustules repellent rose rust spores spot spots sylvestris