WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Saturday, September 23, 2017

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



Fabraea maculata Atk.

Occurrence and importance
Black spot is a fungus disease of the foliage and fruits of pear and quince. The disease is most common east of the Mississippi River, but it can occur anywhere these fruits are grown.

Black spot is of very minor importance as a market disease. The disease is abundant only in poorly sprayed orchards. If uncontrolled, the fungus attacks the leaves and then the fruits. Abundant leaf spotting causes serious defoliation. Thus the fruits are impaired not only by the spots but by lack of nourishment because of the defoliation.

Seriously spotted fruits would not be packed for market. Fruits with an occasional spot might be included. The disease does not develop or spread in transit or storage. Usually the spots are not followed by rot of any kind.

Symptoms
The black spot disease appears as black, roughly circular, slightly sunken spots varying in diameter from about 1/16 to 3/8 of an inch. The spots may be surrounded by a red ring. They may occur on any part of the fruit and are often numerous (see photo). Eventually, because of moisture loss, the surface of the spots may crack.

Control measures
Commercial control of the disease can be accomplished by spraying in accordance with recommendations of the State agricultural experiment station or extension service.

Black spot on pear
Black spot on pear

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