~~ [eee 
exceeded the covered infected ears by 23 percent. (See pp. 5 ~ 6, Tables 4 - 6, and 
Figure 1.) | 
Data bearing upon identified ear rots cover 5 growing seasons and indicate 
the following average prevalences for this period: Fusarium, 40.7 percent; Penicil- 
lium, 5.8 percents; Rhizopus, 5.0 percents; smut, 1.7 percent; Diplodia, 1,2 percent; 
Bsbberella, 0.72 percent; Basisporium, 0.56 percent; and Aspergillus, 0.235 percent. 
Classification according to husk coverage of the ears observed to be infected by each 
fungus indicates that infection by smut, Fusarium, and Penicillium is favored by im- 
perfect husk covernge, that infection by Rhizopus, Aspergillus, and Basisporium prob- 
ably is neither hindered very greatly by -penbest coverage nor favored to any marked 
degree by imperfect coverage, and that infection by Diplodia and Gibberella is in 
some way distinctly encouraged by perfect husk coverage. (See pp. 9 - 18, Tables 7 = 
17, and Figure 2.) 
The fact that imperfectly covered ears predominate in Illinois corn fields 
undoubtedly results in a greater prevalence of ear rot and in a larger field loss 
than would be the case if perfectly covered ears predominated. As an attack on the 
general problem of ear rot control, the development of corn varieties or selections 
characterized by complete coverige of the ear by husks presents an interesting pro- 
‘blem, even though the data at hand indicate thet general plenting of such varietics 
“would possibly result in an inerecased abundance of certain rots now of relatively 
infrequent field occurrence. . 
Little is known at present regarding the nature of the relation between 
initely heritable or whether it is determined by the vigor of ear growth should be 
_. of ear and length of husk. Whether husk coverage is a character that is def- 
“4 
ascertained, | Should it prove to be heritable, combining it with genetic resistance 
r 
to certain diseases in high yielding varieties should result in greatly reduced loss 
4 ; 
from ear rots. 
f19] 
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