92 Report of State Board of Horticulture. 



fungus which was described, its method of development indi- 

 cated and methods for its prevention suggested. Recently 

 Professor Lawrence, of the Washington Experiment Station, 

 has added the interesting information that the same fungus 

 causes a rot of the apple and that by artificial inoculation he 

 has succeeded in producing cankers upon cherry, prune, and 

 pear trees. 



CONFUSION OF NAMES. 



As stated above the disease was variously known as 

 "canker," "dead spot," and "black spot." Ordinarily it is 

 best to accept a common name when once well established, 

 but in this particular instance we believed that since there 

 were three common names about equally well established, 

 that confusion in the designation of the disease could best 

 "be avoided by adopting for it an entirely new name. This 

 seemed all the more necessary by reason of the fact that all 

 of the above names were applied indiscriminately to various 

 diseases of widely different natures. I therefore proposed 

 for this particular disease the name apple tree anthracnose, 

 a name which has since become well established locally and 

 in mycological literature, but which evidently is not so well 

 established in our neighboring State, since in a recent bulle- 

 tin Professor Lawrence, "in order to retain uniformity of 

 names," proposes still another name, "black-spot canker." 



NATURE OF INJURY. 



Apple tree anthracnose attacks principally the smaller 

 Ibranches — those under two inches in diameter — although it 

 also occurs upon larger ones and on the trunks of young 

 trees. The character of the injury produced is well shown in 

 Figs. 7, 8, 9, 10. It usually appears first in the fall upon 

 one and two-year-old wood, soon after the autumn rains 

 begin, as small circular, sometimes slightly depressed, brown 

 areas of the bark, which will continue to increase in number 

 until mid-winter, the larger proportion appearing during the 

 months of November and December. During the tree's dor- 

 mant period these diseased areas apparently increase in size 

 very slowly, although the fungus penetrates to the cambium 

 in which it may spread considerably beyond the limits of the 



