140 Nebraska Agricultural Exp. Station , Research Bui. 20 
The results seem to indicate that selection for freedom from 
root-rot disease by the germinator test does not increase grain 
production under the conditions of the experiment. While these 
disease investigations cover only one year, yet temperature and 
moisture conditions thruout the corn growing season were un- 
usually favorable for the development of this disease. 
Our data suggest that agitation over the root-rot diseases of 
dent corn in this State would not be warranted in the present 
state of knowledge regarding their significance and control. 
Table 59. — Yields of ten highest and ten lowest yielding ears of 
both diseased and disease free Hogue's Yellow Dent and 
Nebraska White Prize corn. 
TEN HIGHEST YIELDING EARS Yield 
per acre 
Bushels 
Hogue’s Yellow Dent selected for freedom from disease 66.8 
Nebraska White Prize selected for freedom from disease 50.2 
Average for both varieties 
Hogue’s Yellow Dent selected as badly diseased 
Nebraska White Prize selected as badly diseased 
58.5 
65.2 
55.4 
Average for both varieties 
60.3 
TEN LOWEST YIELDING EARS 
Hogue’s Yellow Dent selected for freedom from disease. 
Nebraska White Prize selected for freedom from disease 
48.2 
38.9 
Average for both varieties 
43.5 
Hogue’s Yellow Dent selected as being badly diseased. 
Nebraska White Prize selected as being badly diseased 
47.7 
38.8 
Average for both varieties 
43.2 
SOIL AND AIR TEMPERATURES IN THE FIELD IN WHICH YIELD TESTS WERE 
MADE (1921) 
Since the development of the rot fungi most prevalent is en- 
hanced by warm temperature during the time of germination and 
early growth, continuous temperature records were taken in the 
cornfield thruout the growing season. These were taken bv means 
of a combination air and soil thermograph. The air temperature 
was taken within a regulation instrument shelter, at a height of 
