SMALL FRUITS 173 



few roots at first, but eventually reaches all, and results 

 in death of the vine. It is very destructive in Europe 

 and has been noted in several places in the United 

 States. 



The top growths of affected vines show symptoms first; ^ 

 then follows one division after another until a large vine 

 is reduced " to the size of a bushel basket," though numer- 

 ous lateral canes may arise, especially near the base of the 

 plant. The leaf color usually remains normal with no 

 dead tissue, though the leaves sometimes turn yellow, and 

 many of then are reduced in size. After the vine dies the 

 leaves still remain attached to the canes. 



The mycelium of the causal fungus may be seen as a tufted 

 expanse of white dense hyphse, extending along and winding 

 about the roots. Later brown hyphse appear. 



The best treatment is to remove and burn the affected 

 stock, thoroughly stir, air, and dry the adjacent soil. 



Cercosporose (Cercospora viticola (Ces.) Sacc). — Ir- 

 regular dark to black spots upon the leaf often indicate 

 this disease. 



The treatment emploj^ed for Plasmoporose will be useful. 



Root rot, armillariose (Artnillaria mellea Vahl). — Grow- 

 ing within the wood of the roots is the root-rot fungus. 

 When it has attained sufficient vigor and consumed 

 nutriment enough, it develops its spore-bearing part, an 

 edible mushroom, from the surface of the diseased wood. 



This mushroom is from 7-12 cm. high with a cap 10-15 

 cm. in diameter. The stem is swollen near the base, and 

 the cap is conical, frayed at the edge, yellowish, and 

 darkened with age. Upon its lower surface are the 



' Pierce, N. B., U.S. Dept. Agr. Div. Veg. Phys. & Path. Bui. 2, 1892. 



