114 Diseases of Economic Plants 



is the first symptom of disease. The entire bush may suc- 

 cumb, but not usually during the first season. Upon splitting 

 the stems a discoloration of the bark and wood near the base 

 is noticed. No effective treatment is known. 



Mycosphaerella leaf-spot ^^°- ^^^ (Mycosphcerella grossularice 

 (Fr.) Lind., Septoria). — The spots on the leaf are small 

 (3 mm.), circular, brown-bordered, with blanched centers 



Fig. 56. — Currant leaf-spot. After Stewart and Eustace. 



which bear numerous, minute, black pycnidia. Heavy 

 infection causes defoliation. Both currants and gooseberries 

 are affected. Treatment is as for the following disease. 



Angular leaf-spot ^^° {Cercospora angulata Wint.). — This 

 term is applied to a pecuHar spotting of the leaves of both 

 currants and gooseberries. It is likely to occur wherever 

 these plants are grown. The spot is of rather characteristic 

 appearance, irregular or angular in outline, generally about 

 3 mm. in diameter. In the center of the brown or gray, dis- 



