RASPBERRY DISEASES 399 



REFERENCES ON CROWN-GALL 



Swingle, D. B. Fruit diseases in Montana. Crowngall of raspberry 

 and blackberry. Montana Agr. Exp. Sta. Circ. 37 : 326-327. 1914. 



Selby, A. D. A brief handbook of the diseases of cultivated plants in 

 Ohio. Raspberry crown gall. Ohio Agr. Exp. Sta. Bui. 214 : 

 437-438. 1910. 



Selby, A. D. Some diseases of orchard and garden fruits. II. Dis- 

 eases of raspberries and blackberries. 5. Crown gall. Ohio 

 Agri. Exp. Sta. Bui. 79: 108-112. 1897. 



ORANGE-RUST 



Caused by Gymnoconia inter stitialis (Schl.) Lag. 



This is a well-known raspberry and blackberry disease over 

 the eastern United States and southern Canada. It also occurs 

 as far south as Florida and California. The disease is found in 

 Europe and Asia commonly. 



The attacks are limited to wild and cultivated blackberries 

 and raspberries. It is extremely common on black raspberries 

 in New York. In Illinois the Snyder is said to be resistant. 

 On all of these forms the disease is variously referred to as 

 orange-rust, spring-rust, red-rust, bramble-rust, and erroneously 

 as yellows. The disease destroys the usefulness of the leaves 

 and they finally fall. Annual recurrence of this phenomenon 

 results in rendering the plants worthless. Rarely do affected 

 plants recover. Ten per cent rusty plants are frequently 

 reported. Twenty-five per cent or more are recorded. In 

 some localities the orange rust has so seriously affected rasp- 

 berries and blackberries as to make their cultivation unprofit- 

 able. 



Symptoms. 



First signs of the disease are observed in the spring whence 

 the name spring-rust. In April and May, even before the 

 leaves are entirely unfolded, evidences of the disease may be 

 seen. On the upper surface of the leaves glandular bodies are 



