xii List of Plates 



PLATE FACING PAGE 



IX. Potato diseases. Upper tuber, rot caused by late 

 blight ; two bottom tubers, net necrosis. Leaf, 

 under surface, showing effect of late blight . 190 

 (Tuber cuts — Courtesy of Dept. of Plant 

 Pathology, College of Agriculture, Cornell 



University) 

 (Leaf cut — Courtesy of the Geneva Agricul- 

 tural Experiment Station Bulletin 241, Plate 

 XII) 



X. Potato diseases. Top, part of a potato leaf, 

 showing spots of early blight. Bottom, 



rhizoctoniose 194 



(Courtesy Dept. of Plant Pathology, College of 

 Agriculture, Cornell University) 



XI. Potato diseases. Left, powdery scab. Right, 



fusarium dry rot 196 



(Courtesy Dept. of Plant Pathology, College of 

 Agriculture, Cornell University) 



XII. SpindUng potato sprouts. Upper picture, rhizoc- 

 toniose ........ 198 



(Courtesy Dept. of Plant Pathology, College of 

 Agriculture, Cornell University) 



XIII. Preparing the bordeaux mixture .... 217 

 (Courtesy Dept. of Plant Pathology, College of 



Agriculture, Cornell University) 



XIV. The potato harvest. View in an eastern field . 232 

 XV. Combined potato digger and loader . . . 233 



(Photo by W. C. Blake) 

 XVI. Potato products 259 



