198 



Journal of Agricultural Research 



Vol. V. No. 5 



F. radicicola 3319; isolated November, 1913, in association with Mucor 

 sp. 3320 from a "leaky" diseased potato tuber from Moorland, Cal. 

 Culture used, i -month-old pionnotes on a potato cylinder. This strain 

 was similar to 2862, being comparatively inactive. After 51 days' 

 incubation at 21.5 C, only i tuber of 16 inoculated developed a rot. No 

 attempt was made to recover the organism. 



The results of the inoculations with F. radicicola are given in Table IV. 



Table IV. — Results of inoculation of different varieties of potato with original and reiso- 

 lated strains of Fusarium radicicola 



Species and strain No. 



Variety of potato. 



Number of 

 tubers. 



Incubation 

 period. 



Average 

 temperature. 



Percentage 

 of tubers 

 rotting. 



Fusarium radici- 

 cola 2890. 



Fusarium radici- 

 cola 2890 and 

 Rhizoctonia sp. 

 2892. 



Fusarium, radici- 

 cola ^20i'^2&go. 



Fusarium radici- 

 cola ^02 2i'^2&go. 



Fusarium radici- 

 cola 2998. 



Fusarium radici- 

 cola 3236. 



Fusarium radici- 

 cola 2862. 



Fusarium radici- 

 cola Z3^g 



Burbank. . . . 



Idaho Rural 

 Netted Gem 

 Burbank. . . 

 Pearl 



23.0 



23.0 



100 

 100 



100 

 100 

 100 



100 

 100 

 100 

 100 



o 



so 



50 



75 



100 



100 



>=-reisolation of. 



A NEW DRY-ROT CAUSED BY FUSARIUM EUMARTII 



A type of field and storage rot hitherto undescribed was frequently 

 observed in the examination of potatoes from Pennsylvania during the 

 last two years. The character of this rot is as follows : In mild infection 

 of the stem end the tuber shows externally a darkened sunken area with 

 a greenish luster about the stolon insertion. If a thin slice is cut at this 

 point, the parenchyma and the vascular ring are seen to be browned to 

 varying depths. Some of the bundles are discolored to a greater depth 



