180 



DISEASES OF ECONOMIC PLANTS 



be set where the disease has been in 

 previous years. When the fungus 

 has gained access to a plantation, all 

 dead canes should immediately be 

 cut out and burned and all frag- 

 ments scrupulously removed from 

 the ground. Spraying is of doubtful 

 value. 



Mycosphaerellose {Mycosphcerella 

 rubina Stewart and Eustace). — On 

 red raspberry canes in autumn 

 sharply defined brown or bluish 

 black areas from 2-10 cm. long occur 

 on the bark, never on the wood. In 

 the spring these spots bear numerous 

 small pycnidia. 



This disease, due to Sphserella, does 

 not often cause appreciable injury. 



Yellows. — Plants in this disease 

 are stunted, yellowish, and recall 

 peach yellows.^ Laterals are dwarfed, 

 leaves are small, curled downward at 

 the margins, and yellow mottled. 

 Berries dry up without ripening or 

 are insipid when mature. Health 

 and disease may occur upon the 

 same plant. The cane itself and 

 roots appear normal. 

 The cause and remedy are not yet known. 



» Stewart, F. C, and Eustace, H. J., N.Y. (Geneva) .^gr. Exp. Sta. 

 Bui. 226. 



Fin. 77. — Raspberry dis- 

 colored by Sphaerello.se. 

 After Stewart and Eus- 

 tace. 



