din some years at least, overcome the purely mechanical effect of perfect husk cover- 
age 
Since no Aspergillus infection was found in 1931, data on its relationship 
to husk coverage are available only for the 4 years beginning with 1932. According 
to the summary shown in Table 12, no constant correlation appears to exist, While an 
Table 12.-- Relation of Aspergillus rot to husk coverage, 
1932-1955. 
er a ee ee ee eee re ree 
GL i * «= ES 
Excess of 
Number of rotted ears [Percent of rotted ears} open, in 
Year Open __| Covered Open | Covered percent 
1932 A. 2 3369 | 66.7 - 33.4 
1933 13 8 61,9 38.1 23.8 
1934 61 53 556d 46,5 igo 
1935 40 SR A Mie: CP AO aa" 
Average ype cp donot Cie) Re: 
average annual excess of 9.0 percent of infection is shown in covered ears, the 2 
years of highest prevalence oppose the conclusion that open ears are less readily 
infected by showing a decided preponderance of open infected over closed infected 
ears. The data presented are both inconsistent and inconclusive with respect to 
husk coverage but suggest the operation of other, more important factors. 
In determining the relationship of smut infection to ear coverage, the 
exact standard of differentiation adhered to in taking data for other diseases was 
found to be usable with difficulty, and the summary given in Table 13 should be con- 
sidered in that light. Since any considerable number of infected kernels on an ear 
invariably results in the bursting open of the husks, because of the size of the smut 
galls, it is undoubtedly a fact that the very large differences in number and per- 
centage of open infected and closed infected ears in reality grossly exaggerates 
[12] 
