The disease affects peach, nectarine, sweet cherry, sour cherry, and Japanese plum. The disease agent also infects wild chokecherry, which serves as a reservoir for the MLO that may then be transmitted to orchard plantings by several species of leafhopper. Leafhoppers move into orchards in late summer and are favored by red clover and several rosaceous species, especially strawberry and blackberry. Leaves on affected branches fall prematurely, starting at the base of the branch, until only a tuft of leaves remains at the tips of infected shoots.
Fruit drops prematurely.
Symptoms in cherry depend on the rootstock. On mahaleb rootstock, trees are killed suddenly in midsummer by the disease. On mazzard rootstock, infected trees decline slowly, with severe decrease in fruit production. Fruit that is formed is small, pink, and bitter. Be aware of symptoms of this disease.