350 



FUNGOUS DISEASES OF PLANTS 



XLVI. BLACK ROT AND CANKER OF POMACEOUS FRUITS 

 Sphceropsis MaJorum Pk. 



HALSTED, B. D. The Black Rot of the Quince. N. J. Agl. Exp. Sta. Built. 



91 : 8-10. 1892. 

 PADDOCK, WENDELL. The New York Apple-tree Canker. N. Y. Agl. Exp. 



Sta. Built. 163: 331-360. pis. 28-33. l8 99- 

 PADDOCK, WENDELL. Ibid. (Second Report) N. Y. Agl. Exp. Sta. Built. 



185: 205-213. 1900. 



Habitat relations. Under the specific name given above a fruit 

 decay of apples, quinces, and pears has become well known although 



FIG. 169. SPHALROPSIS MALORUM ON APPLE. (Photograph by 

 H. H. Whetzel) 



not serious in the United States. More recently it has developed 

 that this fungus is likewise the cause of an important form of can- 

 ker on trunks and limbs of the same fruit trees. It has been ex- 

 tensively studied only in New York (Paddock). Owing to the 

 occurrence, however, of a variety of cankers on the apple tree, this 

 one is frequently designated "the New York apple canker." 

 This canker has been found to occur in many of the northeastern 



