482 DISEASES OF ECONOMIC PLANTS 



tical in appearance with those upon the grape, and the same 

 treatment is recommended. 

 Powdery mildew. See grape. 



WATER LILY 



Cercosporose (Cercospora). — Circular spots, at first pale 

 green, later yellow, and finally brown and dead, are produced 

 upon the leaves. The dead tissue may break away, leaving 

 irregular holes. 



Soda Bordeaux mixture is recommended, since it is 

 effective and does not spot the leaves. It is beneficial also 

 in removing undesired algal growth. 



