PLUM DISEASES 373 
Control. 
The customary measures of fruit disease control do not readily 
apply to silver-leaf. As a matter of fact, no specific schedule 
for the control of silver-leaf, based upon experimentation, is 
at hand. Certain precautionary measures should be taken: 
(1) affected limbs, trunks and stumps should be wholly de- 
stroyed, and brush-piles should never be allowed to accumulate ; 
(2) avoid the use of the limbs or trunks of any of the previously- 
mentioned fruit-trees as props and posts; (3) avoid injuries to 
the roots, and to the trunks and branches; (4) avoid planting 
young trees showing brown hearts. 
It has been shown that the application of iron sulfate, as used 
in New Zealand, is wholly without value in the control of silver- 
leaf. 
REFERENCES 
Giissow, H. T. Der Milchglanz der Obstbiume. Zeitschr. fiir 
Pflanzenkr. 22: 385-401. 1912. 
Giissow, H. T. Preliminary note on ‘‘silver leaf’’ disease of fruit trees. 
Phytopath. 1: 177-179. 1911. 
Percival, John. ‘‘Silver-leaf’’ disease. Linn. Soc. Bot. Journ. 35: 
390-395. . 1902. 
Aderhold, Rud. Notizen iiber einige im vorigen Sommer beobachtete 
Pflanzenkrankheiten. 4. Milechglanz des Steinobstes. Zeitschr. 
fiir Pflanzenkr. 5: 86-90. 1895. 
The Duke of Bedford and Pickering, S. U. Silver-leaf disease. Wo- 
burn Exper. Fruit Farm Rept. 12: 1-34. 1910. 
The Duke of Bedford and Pickering, S. U. Silver-leaf. Woburn 
Exper. Fruit Farm Rept. 6: 210-224; 234-235. 1906. 
Brooks, F. T. Silver-leaf disease. Journ. Agr. Sci. 4: 133-144. 1911. 
Brooks, F. T. Silver-leaf disease (II). Journ. Agr. Sci. 5 : 288-308. 
1913. 
PockeETs, OR BLADDERS 
, Caused by Exoascus Pruni Fekl. 
This disease has a very general geographical range in Europe 
and in portions of the United States. It has been reported 
from Michigan, Iowa, South Dakota, North Dakota, Ohio, 
