CURRANT DISEASES 221 



REFERENCES ON AMERICAN POWDERY-MILDEW 



Anonymous. American gooseberry-mildew on red currant bushes 



Gard. Chron. 3 : 50 : 473. 1911. 

 Stewart, V. B. Mildew on black currants. Phytopath 5 349 



1915. 



ARMILLAKIA ROOT-ROT 



Caused by Armillaria mellea (Fries) Quel. 



Among the many plants affected by the Armillaria root-rot 

 is the currant. Severe injury is reported from the Pacific 

 Northwest. Symptoms, cause and control are discussed under 

 Apple, page 96. 



FOMES ROOT-ROT 

 Caused by Fomes Ribis (Schum.) Fr. 



This is a root disease which has been observed in New York 

 and Minnesota. It probably occurs elsewhere in the United 

 States, since it affects sassafras as well as currants. The 

 fungus Fomes Ribis produces its fruiting bodies around the 

 base of the bush. These are tough, woody, thin, rough, brown- 

 ish punks, and measure one to two by two to six inches. The 

 diseased roots are abnormally dark, and finally are killed. The 

 destruction of affected plants is advised. 



SILVER-LEAP 



Caused by Stereum purpureum Fries 



This disease, which is by far the most common on the plum, 

 is sometimes found on the currant. As yet no considerable 

 injury is reported on the latter host. (See Plum, page 368.) 



