The fungus survives in the soil as spores. Populations of these spores in the soil increase one to two months after fruit have been harvested. Photo by K. Peter.
It does not occur as frequently as blue mold, however, losses due to Mucor infection can be serious.
Mucor rot develops at the calyx end of fruit or at wound punctures in the skin. Infected fruit completely decay after about two months in cold storage. Decaying fruit become very "juicy" and within this juice are abundant spores of the fungus. This is how secondary spread occurs, which is more common in pears but not in apples.