Rose Diseases 327 



lower portion of the cane it will soon work its way 

 up. The characteristic salmon-colored pustules are 

 usually found in abundance on the affected canes. 

 The rose anthracnose is very similar to that of the 

 raspberry, although the latter is induced by a differ- 

 ent species of fungus. Very little is known of the 

 causal organism of the rose anthracnose. 



Control. All dead leaves and canes should be re- 

 moved and destroyed by fire. Spraying with a 

 standard fungicide is also recommended. 



Leaf Spot 



Caused by Mycospharella rosignea (E. and E.) 

 Lind. 



Symptoms. Purplish blotches appear on the 

 leaves and later develop into sharply defined spots 

 with brown centers and purplish borders. The peri- 

 thecia of the fungus are found in large numbers on 

 the dead tissue. It seems that the one-year-old 

 plants are more susceptible to the disease thaif the 

 two-year-old plants of the same variety. The dis- 

 ease usually occurs in the winter, but seldom causes 

 serious damage. 



The Organism. The perithecia are black and 

 partly erumpent, while the asci are rather oblong 

 and are arranged in two series in the ascus. 



Control. The destruction by fire of all diseased 

 material, and spraying with a standard fungicide is 

 recommended. 



