PLUM DISEASES - 383 



substituted, much will have been done toward the control of 

 plum- wilt. This line of treatment may offer permanent relief. 

 One should avoid making wounds of any sort. Care should be 

 taken to clean and dress all wounds wherever feasible. Control 

 measures against the black-spot pathogene (Bacterium Pruni) 

 are to be emphasized in this connection (see page 311). 



REFERENCES 



Higgins, B. B. Plum wilt. Georgia Agr. Exp. Sta. Bui. 118: 3-29. 



1916. 

 Higgins, B. B. Some serious diseases of plum and peach trees. 



Georgia State Hort. Soc. Proc. 1915 : 42-45. 1915. 

 Stucky, H. P., and Temple, J. C. The plum wilt. Georgia State 



Hort. Soc. Proc. 1911 : 68-72. 1911. 



SCAB 



Caused by Cladosporium carpophilum Thiim. 



Plum-scab, the same as found on the peach, was observed sev- 

 eral years ago on the plum in Iowa. Subsequent observations 

 were made in Delaware, Michigan, Indiana and elsewhere in 

 the United States. It is common in Ontario on wild plums. In 

 Michigan the De Soto variety is said to be particularly sensitive 

 to scab. In Iowa cultivated varieties of Primus americana are 

 reported as susceptible. 



As in the case of peach-scab, the chief losses result : (1) on 

 account of marring the appearance of plums ; they are unattrac- 

 tive and not of first-grade quality ; (2) on account of the crack- 

 ing which accompanies scab, allowing the brown-rot fungus 

 (Sclerotinia cinerea) to enter. The disease is far less common 

 on the plum than on the peach, and in most plum-growing 

 regions it may not be expected to assume dangerous propor- 

 tions (see page 294 for fuller account). 



