WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Sunday, February 17, 2019

WSU-TFREC/Postharvest Information Network/Tree Fruit Market Diseases/pearrhizo

Rhizopus stolonifer (Ehr. ex Fr.) Lind.

Rhizopus rot occurs occasionally on pears that have been injured or are over-ripe. The rot spots are brown (see photo), and the affected flesh is soft and watery with a sour smell. A dense growth of the coarse gray fungus often covers the rotted areas. The presence of black and white mature and immature fruiting bodies gives the gray fungus a salt and pepper appearance, which helps to distinguish this rot from those caused by the blue and gray mold organisms.

Infections develop from spores or by contact, the latter method causing most of the loss once the rot has become established in a box of fruits.

Rhizopus rot can be controlled by holding the fruits at temperatures below 40 °F.

Pear rhizopus rot
Pear rhizopus rot

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