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. Bul. 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 Thim. 
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 Prunus 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). 
