40 
Journal of Agricultural Research 
Vol. XXIX, No. 1 
DATE OF HEADING AND HEIGHT OF PLANT 
The correlation between date of 
heading and height of plant has been 
studied in F 2 material grown at Davis, 
Calif., St. Paul, Minn., and Mandan, 
N. Dak., in 1922, and F 3 material 
grown at Mandan, N. Dak., in 1923. 
The Mandan data are given in Tables 
XXXII and XXXIII. 
height of plant was negative and not 
important or significant at Davis, 
Calif., under very favorable conditions, 
but positive, with increasing importance 
and significance, under increasingly 
unfavorable conditions at St. Paul, 
Minn., and Mandan, N. Dak. In both 
F 2 and F 3 under droughty conditions at 
Mandan there was an important and 
significant correlation between date of 
Table XXXII.— Correlation between date of heading and height of plant in F 2 
material of crosses of Kota and Hard Federation wheats grown at Mandan, N. 
Dak., in 1922 
Table XXXIII.— Correlation between date of heading and height of plant in F 3 
material of crosses of Kota and Hard Federation wheats grown at Mandan, N. 
Dak., in 1923 
Date of heading 
Height of plaDt (inches) 
June 
July 
Total 
_1 
20 
23 
26 
1 
29 
2 
5 
8 
18_ . ... .... 
3 1 
_ 
9 
19 
21. . ... . 
24 
85 
61 
4 
_ 174 
24_ . _ 
23 ! 
114 
114 
10 
3 
1 
_1 265 
27_ 
8 i 
45 
94 j 
9 
8 
1 
2 ; 167 
30_ 
12 
39 ! 
15 
6 
3 
_1 75 
33_ ... . | 
2 
7 i 
3 
6 
1 
_ 19 
36__ ..! 
2 
_ 1 2 
Total_i 
58 
265 
324 
41 
25 
6 
2 | 721 
1 
r=0.410± 0.021 
A summary of the coefficients ob¬ 
tained is as follows: 
F„ 1922: 
At Davis, Calif___—0. 083±0. 023 
At St. Paul, Minn___ . 131 ± . 029 
At Mandan, N. Dak- . 250± .019 
F 3 , 1923: 
At Mandan, N. Dak_ . 410 ± . 021 
It will be noted that in F 2 the corre¬ 
lation between date of heading and 
heading and height of plant. The 
early plants more often were found to 
be short and the late plants to be tall. 
While the results at Davis indicate 
that the Mandan results are largely 
due to environmental conditions, ran¬ 
dom selection of early plants at Mandan 
would, to a certain degree, lead to the 
selection of short plants as well. 
