Fabraea maculata Atk.
Black spot is a fungus disease of foliage and fruits of quince and pear. It can occur anywhere these fruits are grown. Although seldom serious, under favorable weather conditions the black rot fungus can defoliate quince trees by midsummer. Fruit infections can occur throughout the growing season.
Disease symptoms on quince fruits are black, more or less circular, slightly sunken spots ranging in diameter from 1/16 to 3/8 inch. These spots occur on any part of the fruit (see photo). Fruits may be misshapen or cracked when infections are numerous. The disease does not develop or spread in storage or transit. It is not commonly followed by secondary rots.
Commercial control of the disease can be obtained by spraying in accordance with recommendations of the State agricultural experiment station or extension service.
Black spot on quince