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 speciosa Prunus speciosa Prunus speciosa, the Oshima cherry, Japanese オオシマザクラ (Oshima zakura), is native to Izu Ōshima island and the Izu Peninsula on Honshū near Tokyo, Japan. "Prunus speciosa" is a deciduous tree typically high. The leaves are 5–10 cm long and 3–6 cm broad, with a double-toothed margin, and an acuminate apex. The flowers are 2.5–4 cm diameter, with five white petals, gold stamens and brown sepals; they grow in clusters in the spring, and are hermaphroditic. The fruit is a small black cherry about 1 cm diameter. A tree 8 m in circumference and 800 years old is known