Cherry trees are flowering deciduous plants that produce the popular fruit known as cherries. Cherry trees bear light to dark red, round fruit that has smooth skin. The fruit is edible and has either a sour or sweet taste. The fruit of ornamental cherry trees tends to be smaller. In fact, some ornamental trees are sterile and produce no fruit at all, but are notable for their attractive white to pink blooms. As with any plant type, there are several diseases that can affect cherry trees.
Bacterial canker is one of the most common cherry tree diseases. This condition results from two different bacteria that are related to each other. Cankers show up on cherry trees as dark depressions on the trunks and the branches and emit a substance that has a gummy texture. Bacterial canker can also show up in the form of dark-colored depressions on the skin of the fruit. Towards the end of the winter or at the beginning of the spring, limbs that are infected with bacterial canker must be removed. Copper sulfate-based fungicides can also manage the infection, but can also bring the risk of damaging the fruit.
Silverleaf (Chondrostereum purpureum) is a fungal disease that commonly attacks deciduous plants. With this disease, a silvery sheen appears on the leaves. It can also show up as dieback of branches or twigs. The fungal enzymes or toxins cause destruction to the cells of the leaves. Infected sections of the tree need to be promptly eliminated. There are no chemical methods for managing this disease.
Black knot is a type of fungus that affects the spurs of the fruit, as well as smaller limbs and twigs of the tree. Infections tend to show up on the newest growth. The infections appear as pale brown swellings on the wood tissue and bark. As the swellings become bigger with time, they rupture. Plant material that is infected by black knot must be removed immediately.