394 MANUAL OF FRUIT DISEASES 



September. Lesions show anywhere on the surface of the 

 fruit, but are most numerous near the blossom-end. Here 

 they frequently unite, forming one continuous blotch. The 

 spots are one-fifth of an inch or less in diameter, their surface 

 is slightly sunken, and the affected tissue firm. At first the 

 diseased portion is a deeper green than the surrounding tissue. 

 Later the lesions are black. In the center of each spot black 

 specks fruiting bodies of the pathogene appear in great 

 numbers. See fuller discussion of this disease under Apple, 

 page 87. 



REFERENCES 



Brooks, Charles. Quince blotch and apple fruit spot. Phytopath. 3 : 



249-250. 1913. 

 Halsted, B. D. Some fungous diseases of the quince fruit. The 



quince blotch. New Jersey Agr. Exp. Sta. Bui. 91 : 13. 1892. 



BLACK-ROT 



Caused by Physalospora Cydonice Arnaud 



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 con- 

 sideration 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 north- 

 eastern 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. 



