It occurs on all varieties of pears throughout the world. The affected tissues, like those of blue mold rot of apples , are soft and watery, and are easily separated from the adjacent healthy flesh. Cheek rot , as the name implies, develops on the cheek of the fruits. It occurs on all varieties of pears, and is the form of the disease most frequently found on the market.
Infection occurs through cuts, abrasions, punctures, and other breaks in the skin.
Losses from this disease have increased since the storage season for pears has been extended through the use of polyethylene box liners. The fungus grows down through the stem which remains firm, but darkens. It spreads by way of the vascular tissues into the neck of the fruits where the flesh becomes soft and watery. The amount of decay that develops on a single fruit depends on the length of the storage period. It may involve only the stem, the stem and a small area at its base, or the entire upper half of the fruit.