cedar apple rust becomes a serious threat anytime when apples

cedar apple rust serious threat anytime apples eastern red coexist precautions treat trees prevent spread harvest suffers agriculture biology branch control danger disease diseased european farm fruit fungal fungi fungicide fungus garden gardening green growth gymnosporangium immune infected infection infestation leaf leaves nature orange outdoor pale yellow spots parasite pathogen pathology pear phytopathology plant prevention puccinia sabinae sick small spot summer symptoms system treatment tree unhealthy