Diseases of the Plum 323 



first convenient occasion to germinate and penetrate 

 the tissues. A thorough spraying with strong bor- 

 deaux mixture before the buds start will kill many or 

 most of them, perhaps all. Lodeman, who made a 

 special study of this disease, recommends two early 

 sprayings, one "during the warm days of early spring 

 before growth starts, and again when the buds are 

 about to burst." 



The summer spores are mature during May or 

 June; and one or two sprayings should then be given 

 to kill them. One spraying will be enough in all or- 

 dinary cases; but in cases where it is desired to stamp 

 out the disease after it has gained considerable head- 

 way, two sprayings can be well afforded. 



It will be noticed that the two main sprayings 

 here directed for black knot coincide exactly with the 

 two main sprayings advised for the monilia. It is 

 very true that the provident plum grower who gives 

 this treatment "kills two birds with one stone" (ex- 

 cept that in this case there are more than two, as will 

 appear in succeeding paragraphs). 



Shot-hole, or Leaf-spot. This disease has been 

 extensively studied from the mycological side, but 

 seems to have received very inadequate attention by 

 the fruit growers.* 



Like most of the others, it is caused by a fungus. 



*The principal papers relating to the shot-hole fungus are as follows: 



J. C. Arthur, New York State Experiment station Report, 6:347- 

 350. 1887. 



Roland Thaxter, Connecticut Experiment station Report, 1889, page 

 176. Same 1890, page 102. 



W. J. Green, Ohio Experiment station Bulletin II, 4:216. 1891. 



D. G. Fairchild, United States Division of Vegetable Pathology Bul- 

 letin 6:39-40. 1894. Journal Mycology, 7:253-256. New York State 

 Experiment station Report, 11:659. 1892. United States Division of 

 Vegetable Pathology Bulletin 3:63. 1892. 



S. A. Beach, New York State Experiment station Report, 12:688-693. 

 1893. New York State Experiment station Bulletin 98. Xew York State 

 Experiment station Bulletin 116. 



L. H. Pammel, Iowa Experiment station Bulletin 30:289-301. 



