PLATE XXXVI 



Fig. I, 2. — Stem-end blackrot produced by stem-end punctures with a needle 

 carrying Fusariumradicico la. Netted Gem and Idaho Rural potato tubers. Laboratory- 

 inoculations. 



Fig. 3. — Lenticel blackrot produced by spraying the tuber with a spore suspension 

 of F. radicicola. Netted Gem tuber. Laboratory inoculation. 



Fig. 4. — Same tuber as shown in figure 3; after having been kept a few days longer 

 in the moist chamber. Note the tufts of F. radicicola that have appeared. 



Fig. 5. — Stem-end blackrot produced by spraying an Idaho Rural tuber with a 

 spore suspension of F. radicicola. Laboratory inoculation. 



Fig. 6. — Stem-end blackrot produced by the inoculation of the tuber stolon. Idaho 

 Rural tuber. Laboratory inoculation. 



Fig. 7. — Blackened vascular system produced by the inoculation of the tuber 

 stolon. Idaho Rural tuber. Laboratory inoculation. 



