affected by the fungal disease gymnosporangium sabinae pear, rust-infected pear leaves

agriculture background branch closeup danger detail disease diseased flora foliage fungal fungi fungicide fungus garden gardening green gymnosporangium heteroecious immune infected infection infestation juniper leaf leaves natural nature orange outdoor parasite pathogen pathogenic pathology pear pest phytopathology plant prevention rust sabinae sick spores spot summer system treatment tree unhealthy yellow