338 Report of the Horticulturist of the 



Pjcnidia containing mature spores were also found to be abun- 

 dant on the dead bark surrounding the points of inoculation that 

 were made from the cultures of Sphaeropsis. Plate XXX, fig. 3, 

 is from a photograph of one of the limbs of an apple tree as it 

 appeared at the close of the present season, that was inoculated 

 in the spring of 1898 with cultures made from a cankered limb. 

 Pycnidia are numerous on the surface of the bark and on the 

 decorticated w^ood as well. 



The result of over fifty inoculations made from cultures that 

 were obtained from cankered apple-tree limbs prove that the 

 apple-tree canker of New York apple orchards is caused by a 

 fungus of the genus Sphaeropsis. In every instance where the 

 incisions were made through to the wood, typical cankers were 

 produced and mature fruit of the Sphaeropsis formed on the de- 

 caying bark and in some instances on the decorticated wood also. 

 The inoculation experiments were repeated many times during the 

 season of 1899 and the results have been the same. 



GEOGRAPHICAL DISTRIBUTION 



A personal examination of a great many orchards during the 

 past two seasons reveals the fact that this canker of apple trees 

 is widely distributed in the orchards of New York. In fact an 

 orchard is rarely seen that is entirely free from the diseape. As 

 is to be expected, however, it is more abundant in Pome localities 

 than in others, and as has been previously mentioned, some varie- 

 ties are more subject to the disease than others. It is specially 

 injurious in many of the apple gi'owing sections of western New 

 York. 



Responses to a circular letter sent to the authorities of the vari- 

 ous experiment stations, together with personal examinations, 

 bring out the positive information that this canker occurs in Con- 

 necticut, Indiana, Maryland, Michigan, Pennsylvania and Ver- 

 mont, and that it probably occurs in Hlinois, Maine, Massachu- 

 setts, ]\[innesota. New Jersey, West Virginia and portions of 

 Canada. It seems probable that when the disease becomes more 



