Cream colored tufts of spores are sometimes present. Infection occurs in the orchard around petal fall or just before harvest. The fungus survives as mycelium and conidia in branch cankers. May. Acervuli first appear during late summer and fall about a year after infection. The cankers do not expand after the first year, but the anthracnose fungus can sporulate on the dead bark for several years.
Sporulation occurs during cool, moist weather.
Conidia are exuded in a gelatinous matrix and splashed to wound cites by rain. The fungus penetrates the bark directly. Canker removal is recommended because it destroys the inoculum source required for new canker development and bull's eye rot. A dormant spray of Bordeaux mixture, followed by a Bordeaux application, captain, ziram, or fixed copper prior to autumn rains, is recommended for anthracnose canker control. Spartan, Gravenstein, Chehalis, and Baldwin are highly susceptible to anthracnose.