Vol. XXI, No. 7 
430 
Journal of Agricultural Research 
In 1919 hot, dry weather prevailed during July, and although the tem¬ 
perature was favorable during August the corn did not make a maximum 
development because of a deficiency of moisture. The corn was planted 
much too thick and unfortunately was not thinned until it was 3 or 4 
feet high. This no doubt decreased the yields to a considerable extent. 
The smooth type sustained the greatest injury because of the relatively 
thick stand for that type. In spite of this handicap the smooth type 
made the highest yield, although the difference as compared with the 
rough type is probably not significant. Altogether, the results show that 
for the conditions of this test a smooth type of corn will yield fully as well 
as medium or rough types. 
The effect of continuous selection for types on the length, circumfer¬ 
ence, and weight of the ears, number of rows of kernels per ear, the 
length of kernel, and the percentage of corn to cob were also studied. 
Data for these characters for the seed ears used for planting the respec¬ 
tive type lots each season and for the progeny of each lot were recorded 
and tabulated. 
LENGTH OF EARS 
The effect on the length of ears is shown in Tables II and III. It will 
be noted that the smooth type of ear used for planting consistently aver¬ 
aged longer than those for the other types, and the average length of ear 
of the progeny of this type was slightly greater. On the other hand, the 
rough ears were shorter than the others. This same relation between 
indentation and length of ears is found in the progeny, as shown in 
Table III. 
Table II .—Frequency distribution of ears of various lengths used in pla?iting the type 
test of Commercial White corn , IQ16-IQ20 
Year and type. 
Number of ears having a 
length (in inches) of 
Num¬ 
ber 
Mean 
6 
6 A 
6 K 
6K 
7 
7 X 
7 K 
8 
&A 
SA 
8K 
9 
9 l A 
9 M 
9 K 
10 
10X 
10A 
roK 
11 
nK 
of 
ears. 
length. 
1916: 
Smooth. 
5 
5 
4 
IO 
3 
4 
5 
3 
1 
1 
40 
Inches. 
9■ 35 
Medium. 
3 
5 
3 
9 
8 
4 
1 
5 
1 
1 
40 
9. 42 
Rough 
2 
5 
6 
6 
3 
6 
6 
2 
4 
40 
9 - 49 
X917: 
Smooth. 
3 
7 
4 
4 
4 
4 
2 
2 
1 
5 
3 
3 
1 
40 
9.16 
Medium. 
2 
1 
6 
7 
8 
3 
3 
4 
2 
3 
2 
40 
9 - 13 
Rough. 
1 
X 
I 
1 
6 
5 
8 
4 
3 
2 
4 
2 
1 
X 
40 
9. 14 
1918: 
Smooth. 
I 
2 
2 
3 
4 
4 
4 
4 
2 
26 
9. 64 
Medium. 
X 
I 
2 
6 
6 
4 
3 
3 
1 
2 
2 
X 
1 
33 
8. 72 
Rough. 
2 
1 
3 
x 
2 
6 
1 
2 
2 
2 
3 
2 
X 
28 
8.G4 
1919: 1 
Smooth. 
1 
X 
2 
2 
3 
4 
3 
2 
1 
1 
20 
8. 42 
Medium. 
1 
2 
4 
2 
2 
2 
2 
2 
2 
20 
7.83 
7. 01 
Rough. 
2 
X 
I 
1 
2 
X 
2 
2 
3 
2 
i 
1 
20 
1920: 
Smooth. 
2 
2 
4 
5 
7 
4 
6 
3 
3 
1 
2 
x 
40 
40 
8. 96 
8 . 44 
Medium. 
3 
4 
7 
5 
8 
6 
4 
2 
1 
Rough. 
I 
I 
2 
2 
4 
9 
6 
5 
4 
2 
2 
1 
1 
40 
7. 72 
0.11 
Five-year aver¬ 
age: 
Smooth. 
Medium. 
8. 73 
8.40 
Rough.. 
