The fungus also may move from blighted blossoms into the twigs, causing small, elliptical cankers. In some cases, these cankers will girdle and kill twigs. Bleeding or gum production often is associated with twig cankers. The second phase of the disease occurs as fruit begins to mature. Inoculum produced on blighted blossoms, twig cankers, or from nearby wild plums infects maturing fruit.
Affected fruit develops light brown spots that enlarge rapidly.
The fruit may be completely rotted within a day or two. The fungus sporulates profusely on the rotting fruit, giving the peaches a dusty brown appearance. The rotting fruit shrivels to form a structure called a mummy, which is completely colonized by the brown rot fungus. These mummies may remain attached to the tree or drop to the orchard floor. Fruits thinned at or after pit hardening also provide a good medium for the fungus and are an important source of inoculum for mature fruit infection.