22 
Journal of Agricultural Research 
Vol. XXIX, No. I 
Further evidence that earliness is 
the dominant condition in this cross 
is shown by the results from St. 
Paul and Mandan in Table XIII 
Fig. 2.—Frequency distribution, by dates of heading, of F 3 
selections and of the Kota and Hard Federation parents at 
Mandan, N. Dak., in 1923 
lent data were obtained, which show 
the F 2 progeny to be much more vari¬ 
able than either of the parents and the 
mode and the mean to be the same as 
that of the early Hard Federation 
parent. The bimodal curve for 
the F 2 progeny and Hard Federa¬ 
tion at Mandan was due princi¬ 
pally to a rain which occurred on 
the 2d of July. It does not seem 
desirable to attempt a factor 
interpretation. 
In 1923 at Mandan, N. Dak. y 
721 F 3 plants selected from 
among the 433 F 2 families grown 
there, were labeled for date of 
heading. At least one plant 
was labeled in each family and 
for the awnless, apically-awn- 
letted and awned strains several 
plants were labeled in the most 
promising strains. The plant 
labeled usually was the earliest 
to head. Very few strains ap¬ 
peared as uniform in date of 
heading as the parents. The 
data thus obtained in F 3 in com¬ 
parison with the parents are 
shown in Table XV and graphi¬ 
cally in Figure 2. 
The average date of heading 
for the F 3 selections was June 
25, that of Hard Federation June 
24, and that of Kota July 2. 
As earliness was one of the 
principal characters for which 
selections were made it is ap¬ 
parent that the desired earli¬ 
ness is being obtained. 
Table XV.— Date of heading of 721 F 3 plants of the Kota-Hard Federation cross, 
in comparison with the parents, grown at Mandan, N. Dak., in 1923 
Frequency classes 
• F3 hybrid 
Hard Federation 
Kota 
Number 
Percent¬ 
age 
Number 
Percent¬ 
age 
Number 
Percent 
age 
June 20 _ . 
58 
265 
324 
41 
25 
6 
2 
8.0 
36.8 
44.9 
5.7 
3.5 
0.8 
0.3 
11 
33 
47 
4 
11.6 
34.7 
49.5 
4.2 
23_ . . _ 
26 . 
29_ 
26 
42 
7 
34.7 
56. a 
9 . a 
July 2___,_ 
5.. . . . .. 
8__ 
721 
100.0 
95 
100.0 
75 
100.0 
and the central and lower portions, re¬ 
spectively, of Figure 1. At these points 
the material was spring sown and the 
heading period was shorter. At St. 
Paul heading started suddenly and the 
data obtained do not show normal 
variability. However, earliness ap¬ 
pears dominant. At Mandan exc31- 
height OF PLANT 
Another growth character, height of 
plant, is an important economic factor 
in wheat production, because it may 
determine the method or ease of har¬ 
vesting. It is inherited in the same 
manner as other characters. 
