leaves of a rose infected with a disease marssonina rosae

affected aspen attack black chlorosis close closeup control damage danger defoliation detail diplocarpon disease diseased fungal fungi fungicide fungus gardening green ill infected infection infest insect leaf leaves macro marssonina microorganism mold mould natural necrosis parasite pathogen pathogenic pathology phytopathogenic phytopathology problem rosa rosae rose sick spot symptoms treatment