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 Sclerolium Rollsii, e. pure culture of 

 S. Rolfsii. 



