Utah State University Extension
Three elements need to be present for a plant disease to develop: a host, a suitable environment and a pathogenic organism. Most plant pathogens are either fungi or bacteria. Below are ten of the more common pathogenic plant diseases associated with woody ornamentals in the Intermountain area.
Gunnell, JayDee, "Top Ten Pathogenic Diseases of Woody Ornamentals" (2010). All Current Publications. Paper 1083.