180 



DISEASES OF ECONOMIC PLANTS 



bo 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. 



Sphserellose {Sphcerella 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 Sphaerella, 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) Agr. Exp. Sta. 

 Bui. 226. 



Fig. 77. — Raspberry dis- 

 colored by Sphasrellose. 

 After Stewart and Eus- 

 tace, 



