The rot begins as a small brown spot which expands rapidly, developing a brown color and a more or less firm texture. The fruit becomes more susceptible as it matures. Brown rot is especially severe during wet periods. Infected blossoms, twigs and fruits soon become covered with gray-brown tuffs of spores. The brown rot fungus overwinters on mummified fruit on the ground or tree and in infected twigs.
Peach scab occurs on leaves, twigs and fruit causing small, circular to oval-shaped spots.
The infected areas are dark brown to black in color and entirely superficial. On red skinned or blushed varieties, fruit spots may be surrounded by a light-colored halo. Economic damage is mainly due to loss of fruit appearance quality, although heavily infected fruit may become misshaped or cracked. Initial fruit infection occurs during the first four weeks after shuck fall. The disease overwinters on twig lesions.