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 avium in classical schools, it must once more be said that cherry trees (at least the bird cherry) existed in Italy before Lucullus, and that the famous gourmet did not need to go far to seek the species with the sour or bitter fruit. De Candolle suggests that what Lucullus brought back was a particular cultivar of "Prunus avium" from the Caucasus. The origin of cultivars of "P. avium" is still an open question. Modern cultivated cherries differ from wild ones in having larger fruit, 2–3 cm diameter. The trees are often grown on dwarfing rootstocks to keep them smaller for