Distribution: In eastern US, primarily a problem in MI, the Hudson Valley of NY, and southern New England, with occasional reports from the Cumberland-Shenandoah region.
This disease is caused by a mycoplasma and infects many varieties of stone fruits. On cherry, infected trees tend to develop a dieback and a generally unthrifty appearance (A). Infected trees decline, but the rate of decline is dependent on the rootstock. Cherry trees on resistant rootstock, such as Mahaleb, decline rapidly because of a hypersensitive response at the graft union. On susceptible rootstock, such as Mazzard or Colt, decline occurs over several years. Cherry fruit on these trees tend to be small, flattened, pointed, and pale-colored and are confined to a few branches, but mixed with some normal fruits (B). On peach, leaves curl inward after several months. Water-soaked spots turn red, become necrotic and drop out, giving leaves a tattered appearance (C). Localized areas or the entire canopy defoliates, leaving foliage only at the tips. The entire tree may show symptoms 2 to 3 years after the initial infection (D).