Taphrina pruni being larger than the healthy one. As a fungus, cool and wet weather conditions promote the germination of spores, whilst warm and dry weather results in infection rarely taking place. Colonisation can become extensive and eradication very difficult. The disease can to some degree be controlled by carefully removing infected branches, witch's brooms and fruit before the infective air borne spores are produced. Applications of copper-containing fungicides have a degree of control over the fungus. Taphrina pruni Taphrina pruni is a fungal plant pathogen of blackthorn (Prunus spinosa) that causes the Pocket or bladder Plum gall, a chemically induced distortion
Prunus pensylvanica Prunus pensylvanica Prunus pensylvanica, also known as bird cherry, fire cherry, pin cherry, and red cherry, is a North American cherry species in the genus "Prunus". "Prunus pensylvanica", grows as a shrub or small tree, usually with a straight trunk and a narrow, round-topped crown. It grows tall and in diameter. Trees up to tall have been found growing in the southern Appalachians, with the largest found on the western slopes of the Great Smoky Mountains. Its foliage is thin, with leaves long and wide. Flowers occur in small groupings of five to seven with individual flowers across. The fruit