168 MANUAL OF FRUIT DISEASES 



As a rule the disease is not of sufficient importance to warrant 

 spraying for its control. 



YELLOW LATE-RUST 

 Caused by Kuehneola albida (Kuehn) P. Magn. 



This is a disease peculiar to wild and cultivated blackberries. 

 It is found in Europe and in eastern North America. In the 

 northern United States where it occurs there is no need for 

 alarm on account of its late fall appearance. However, it may 

 assume a more important role south of New York State. 



Symptoms. 



Plants in sandy soil are said to be more affected. Rust 

 pustules are produced on the canes the last of May or in June, 

 or about blossoming time. These are bright, lemon-yellow 

 in color, and measure from one-eighth to one-half an inch in 

 diameter. They are usually found on the stem near the ground. 

 Later the leaves are affected, the disease first appearing on the 

 lower surface of the leaves of fruiting canes, then on those leaves 

 attached to the new canes. The fruit-stalks and flowers are 

 also rusted. 



The general appearance of the disease has given rise to the 

 names yellow late-rust, white-rust, cane-rust and late-rust. 



Little is known of the seasonal cycle of the causal fungus, 

 Kuehneola albida, and of its control. 



REFERENCES 



Stewart, F. C., Rolfs, F. M., and Hall, F. H. A fruit-disease survey of 

 western New York in 1900. Blackberry diseases. Yellow fall 

 rust. New York (Geneva) Agr. Exp. Sta. Bui. 191 : 306-307. 1900. 



Wilson, G. W. Rusts of blackberries, dewberries, and raspberries. 

 Late rust. Cane rust. North Carolina Agr. Exp. Sta. Rept. 35 : 

 58-61. 1912. 



Stone, G. E., and Smith, R. E. A late rust of the blackberry (Chry- 

 somyxa albida, Kiihn). Massachusetts (Hatch) Agr. Exp. Sta. 

 Rept. 9 : 74. 1897. 



