Corn Investigations 
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type selections were not taken thruout the entire period of the 
tests, the measurements and observations made lead to the con- 
clusion that ear type selections indirectly result in a selection of 
correlated plant characteristics which differ in their adaptation 
to various environmental conditions. Selection of long, slender, 
smooth ears results in the isolation of types having a smaller 
and earlier maturing vegetative development than where the 
opposite large, rough type of ear is selected. 
4. In an extensive comparative one-year test of ears disease 
free versus ears infected with root-rot diseases, as determined by 
the germinator test, the original unselected corn yielded 49.7 bush- 
els, the disease free 50.2 bushels, and that designated as badly dis- 
eased corn 50.6 bushels per acre. No advantage resulted in regard 
to grain yield, barrenness, lodging, or soundness from such disease 
free selection. On the other hand, when the ear-to-row plats 
involved in this test are classified into rough, medium, and 
smooth groups without any reference to the presence or absence 
of root-rot diseases, the respective relative yields of shelled grain 
per acre are 100, 103, 106 as compared with 102 for the original 
unselected corn. Previous correlation of the germinator results 
with the various ear and kernel types indicates from 10 to 20 
per cent greater freedom from root-rot diseases in case of the 
slender, smooth ear with horny kernels than in case of the large, 
rough, starchy, deep-grained ear. It seems possible that the in- 
creased yield secured by some investigators following selection 
of disease-free ears by the germinator test is, in part at least, 
associated with their prescribed preliminary selection of the 
smooth, slender, horny ears for seed purposes. Wherever corn 
types are being grown which tend to be somewhat too large and 
late maturing for their environmental conditions, selection of 
this smooth type of ear, whether because of root-rot disease con- 
siderations or otherwise, is likely to result in increased produc- 
tion because of the better adaptation of plant types represented 
in this type of ear. These type considerations apply where the 
various types are selected from the same general variety of corn. 
In the case of seed grown under field conditions of promis- 
cuous pollination, the progeny shows a tendency to come true to 
the ear type planted. In 1921, the percentages of rough, medium, 
and smooth ears harvested from large rough ears, long smooth 
ears, and the original unselected Nebraska White Prize corn 
were respectively 52, 35, and 13 per cent, 16, 40, and 44 per cent, 
and 30, 38, and 32 per cent. The difference in ear circumfer- 
ence, number of rows on an ear, and kernel length between these 
