The disease which is discussed under Apple (page 45) occurs on all pomaceous fruits, including the quince. The trouble manifests itself on quince almost entirely on the fruit and is referred to as Black Rot. The foliage and woody parts of quince are rarely affected to any extent; consequently the Leaf Spot and canker forms of this disease are not given consideration in this discussion.

Black Rot of quince was first observed in Connecticut about 1890, when it was prophesied that it might become a serious menace to quince - culture. While its range over the northeastern United States is general, and its occurrence in and about Ohio and New Jersey is common, yet the disease ranks as one of minor importance on the quince. The disease is well known and destructive on the apple.

Black Rot makes its appearance on green fruit in August and may be in evidence until the fruit is picked. A lesion begins as a brownish speck. It may be located anywhere on the surface of the fruit, but the blossom-end commonly marks the center of a diseased area. As the size of the spot increases, the color darkens, the affected skin wrinkles, and black pimples may appear over the surface. Sometimes these bodies do not show until the whole fruit is involved; this is usually a matter of two or three weeks. Finally the fruit is completely mummified and after drying is no more than one - fourth its normal size. See fuller discussion under Apple, page 45.

References

Sturgis, W. C. Black rot of quinces. Connecticut Agr. Exp. Sta.

Rept. 1892: 43-44. 1893. Sturgis, W. C. Diseases of the quince. Black Rot. Connecticut Agr. Exp. Sta. Bul. 115: 6-7. 1893. Halsted, B. D. Some fungous diseases of the quince fruit. The black rot of the quince. New Jersey Agr. Exp. Sta. Bul. 91: 8 - 10.1892.