Articles

Stone Fruit Disease - Plum Pockets

In the northeastern United States, the most important disease affecting American-type plums is known as plum pockets, or bladder plum. It is caused by Taphrina communis.

Save for later Print

Updated:

April 3, 2023

Skip to the end of the images gallery

Source: Mike Schomaker, Colorado State Forest Service, Bugwood.org

Skip to the beginning of the images gallery

A number of diseases cause curling of leaves.

Symptoms

First evidence of the disease on fruit are small, white blisters. These enlarge rapidly and soon involve the entire fruit. The fruit becomes spongy and tissues of the seed cavity wither and die. Enlarging rapidly, fruits grow 10 times their normal size, turn reddish, and become so misshapen that they are hardly recognizable. As their spongy interiors dry up, the plums turn velvety gray as spores grow on their surfaces.

New shoots and leaves are usually infected as well as fruit. Shoots thicken and are often curled or twisted. Diseased leaves are thickened and curled as in leaf curl.

Disease cycle

Spores overwinter on twigs and during cool, wet periods in early bloom may be splashed to the opening buds, where infection takes place. Developing ascospores give the infected fruit a velvety gray appearance, thus completing the disease cycle.