For most fruit types, including apples, bruising is the most
common type of postharvest mechanical injury. A survey for 12
years in the New York market (summarized by Knee and Miller,
2002) indicated that 6% of apples were affected by bruising.
In this survey, mechanical injury was never the most common
defect for most fruit (including apples). Usually one or more
kinds of fungal diseases exceeded the mechanical injury, predominantly
gray mold (Bortrytis) or blue mold (Penicillium).