Plum pockets

The disease known as "plum pockets" is caused by the fungus Taphrina communis. This fungal pathogen specifically targets stone fruit trees, invading the developing ovaries and disrupting normal plant growth regulation, which leads to the formation of distorted, inedible fruit tissues.

The primary host for this pathogen is the domestic plum, though it can also infect other species within the Prunus genus, such as sloe or wild plums. Because the fungus infects the fruit directly, the economic impact is high, as an entire harvest can be ruined if environmental conditions favor the pathogen's development.

Symptoms become visible shortly after the fruit set. Infected plums expand prematurely and become abnormally elongated, flattened, or curved. Crucially, the stone fails to form inside the fruit, leaving a hollow, distorted structure that eventually turns grey or white due to the presence of fungal spores on the surface.

The disease cycle is heavily influenced by cool, wet weather during the blossoming period. The fungus overwinters as blastospores on the bark and dormant buds. When environmental moisture is high, these spores are disseminated by rain and wind to infect the newly forming fruit, marking the beginning of the seasonal infection cycle.

Control strategies emphasize sanitation and chemical intervention. Growers should remove and destroy any mummified or malformed fruit before the spores mature and release. Furthermore, a rigorous fungicide spray program applied before bud break is essential to prevent the fungus from establishing, ensuring the long-term health of the orchard.