WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Sunday, February 17, 2019

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

Superficial scald, also known as Anjou scald, is a physiological disease that occurs on the varieties Anjou and Packham's Triumph. It is characterized by a brown discoloration of the skin, which detracts from the appearance of the fruits (see photo). Superficial scald is restricted to the skin. It is not accompanied by sloughing of the skin or by unpleasant odors as is senescent scald. The disease may not be evident when the fruits are removed from cold storage, but large amounts of scald may develop after pears have ripened for a few days. Although the disease resembles ordinary scald of apples in symptom expression, and although it can be controlled with oiled wraps, superficial scald of pears does not appear to be associated with immaturity at harvest as is the case of ordinary scald of apples.

Control measures
Oiled paper wraps control the disease satisfactorily until early March, but they are not effective later in the season. A scald-inhibiting chemical, ethoxyquin (6-ethoxy-1, 2-dihydro-2, 2, 4-trimethylquinoline), used as a spray or dip or as impregnated wraps, provides good control of the disease throughout the storage season.

Pear superficial scald
Pear superficial scald

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us