A Dry Rot of the Irish Potato Tuber 51 
SURFACE INOCULATIONS OP EARLY OHIO TUBERS AFTER REMOVAL OF 
THE SKIN. 
Figs. 1, 2. Inoculation of Early Ohio tubers by removal of the skin. 
Photographed five weeks after inoculation. Kept in a moist chamber 
with a small dish of water; the first week at 8° to 10° C. and then at 
laboratory temperature. Medium applied with the fungus. 
Table 12. — Results of inoculation, icith and without media, on 
the surface after the removal of the sMn of the tuber. 
No. of 
inoculations 
No. of 
successful 
inoculations 
Extent of 
rot 
Medium 
Tempera- 
ture 
Humidity 
18 
0 
None 
Yes ... . 
25 to 27 c C. 
Saturated air 
18 
0 
None 
Yes ... . 
25 to 27" C. 
Over CaCl 2 
18 
0 
None . . 
Yes ... . 
8 to 10 c C. 
Over CaCl2 
18 
11 
1 cm. deep. 
Yes ... . 
8 to 10 C. 
Samrated air 
30 
18 
Prominent; 
2 cm. deep 
Yes ... 
8 to 10 C. 
Saturated air 
30 
4 
Moderate . . 
No ... . 
8 to 10° C.j 
Saturated air 
It is evident in this case that the greatest amount of rotting 
occurred at high humidity. 
Figs. 3, 4. Inoculation of Early Ohio tubers by removal of the skin. 
Photographed four weeks after inoculation. Kept over CaCL; the first 
week at 8° to 10° C. and then at laboratory temperature. With 
medium. 
