FIG. 63. POTATO DISEASES. 



a. Powdery dry rot, b. Rhizoctonia lesion on young potato sprouts (after W. A. 

 Orton), c. Rhizoctonia sclerotia on seed potato tubers, d. melters, artificially in- 

 duced by inoculating with a pure culture of Sclerotium Roljsii. e. pure culture of 

 5. Rolfsii. 



