Cherry trees are flowering, fruiting trees that are highly susceptible to a fungal infection called brown rot. The fungus causes rotting of the cherry fruit, and in severe cases leaves also decay. For successful prevention of brown rot, keep trees vigorous through proper care such as appropriate sun exposure and preferred soil type. Understand symptoms and damage in case your tree displays signs of illness.
Cherry Tree Description
Cherry trees belong to the Prunus species—trees with stone fruit that are susceptible to infection by brown rot. Sargent cherry trees (Prunus sargentii), for example, are deciduous trees with a rapid growth rate that display dark, glossy green leaves that turn red, orange or yellow during the autumn season. The solitary flowers are pink to dark pink and cherry fruit develops into purple-black hues, according to the North Carolina State University Cooperative Extension Service. Trees reach a height and width of 20 to 40 feet.
These ornamental fruiting trees thrive in full sun to partial shade and are drought-tolerant. Keep cherry trees out of polluted environments; if your area is at all polluted, make sure the area surrounding your tree allows for good air circulation to prevent suffocation. Cherry trees do, however, thrive in windy environments. Soil must be well-drained for proper water absorption. Do not keep your cherry tree in wet sites or standing water or they may become waterlogged, causing decline and providing the ideal environment for fungal infection.
Brown Rot Disease
Brown rot disease is caused by a fungal infection. The fungi Monilinia fructicola and M. laxa both cause fruit rot of Prunus species plants. Inhabiting branches, flowers, fruit and twigs even after death, the fungi are spread sporadically and often form fruiting bodies or mushrooms on fallen fruit. Usually during the spring season, wind and rain are responsible for the spread of fungal spores that infect water-saturated flower blossoms. Fungi can create disease growth on any part of the plant, including leaves.
Symptoms and Damage
Brown rot of cherry trees causes flowers to change to a light brown color and to take on a wet appearance. Gumming and the development of fungal growths may also appear on all parts of the plant, particularly on twigs, according to the Oregon State University Extension. Buff-hued spores may collect on fruit and the fruit will eventually rot in small areas at first and then will decay and fall to the ground. Infected leaves may turn brown, wilt and rot.
For control of leaf rot on cherry trees, first consider cultural management. Collect and destroy any affected plant parts, keep trees vigorous through proper care and avoid the incidence of wounds on trees through which fungi invade and cause infection. For chemical control, apply fungicides like triflumizole while the cherry tree is flowering. Generally two applications are necessary for effective control. As a biological control method, apply Bacillus subtilis, a control with a protein-based active ingredient that you may apply to trees up to the day of harvest as well as on the day of harvest, according to the Oregon State University Extension.