July i, 1921 
Pathogenicity of Corticium vagum on the Potato 
47i 
The results of this experiment, as related to temperature, agree essen¬ 
tially with those obtained in experiment 3 (Tables V and VI and fig. 4). 
The primary difference appeared in the fact that the highest percentage 
of diseased plants were found in the soil held at 15 0 C. When considered 
from the standpoint of total tissue destroyed, the high point apparently 
falls at 18°. 
The percentage of infection of the Early stems was much lower and 
less uniform than that obtained with the Irish Cobbler stems in experi¬ 
ment 3. 
Fig. 3.—Relation of soil temperature to the severity and to the distribution of the injury caused on potato 
stems by Corticium vagum (experiment 3). 
Table VI. — Percentage of diseased stems in sterilized and unsterilized soil 
Temperature (° C.). 
Sterilized 
soil. 
Unsteri¬ 
lized soil. 
8.8. 
30.O 
26.6 
22.2 
30.0 
6 l.O 
71.4 
71.4 
33-3 
53-3 
i 5-3 
11.8. 
I C . 2 . 
18.2. 
20.8. 
22.2 
20.0 
23.O 
23.4.. 
27.4. 
