a close up photo of a grebera flower affected by grey mildew botrytis cinerea. pathogen botryotinia fuckeliana

affected attack botryotinia botrytis chemical cinerea close closeup conditions control controlling cultivation daisy damage damp disease diseases flower fuckeliana fungal fungi fungicide fungus garden gardening gerbera grebera grey high humidity illness infected infection macro management mildew mold mycelium patches pathogen pathogenic phytopathology plant powder powdery preventing rotten rottenness soft species spores susceptible symptoms treatment white