198 



Potato Diseases 



" No plant disease in this generation has been the subject of such 

 general discussion as that known in Germany as the ' l^lattrollkrank- 

 heit ' herein named ' Leaf-roll.' None has aroused greater difference 

 of opinion as to its nature and cause, and no other single malady of 

 plants is to-day receiving so much investigation by skilled pathologists 



Fig. 7. Foliage from a plant of the President potato affected v/ith curl showing the under 

 surface of the leaflet exposed owing to the curl, small brown blotchss and dead 

 leaflet-ends. 



as this. Possibly no disease which has appeared since the advent of 

 Phfjlophihora injeslans in the forties presents a greater menace to potato 

 culture"— W. A. Orton, Feb. 10, 1914 in U.S. Dept. Agric. Bur. PL 

 Ind. Bull, 64 (1914). 



