FACTORS FOR YIELD AND QUALITY OF SPRING WHEAT 
51 
s=s 
average of the reciprocal crosses from the average of the total hybrid 
population in each case is 0.06 ±0.04, indicating but little, if any, 
paternal influence. 
The variability of the hybrids in comparison with the parents, as 
indicated by coefficients of variability, is as follows : 
Coefficient of variation 
F 2 hybrids 5. 108±0. 102 
Hard Federation 5. 081 ± .251 
Marquis 5. 398± .263 
The data show that the F 2 hybrids are slightly more variable in 
crude-protein content than Hard Federation and that Marquis is 
slightly but not signifi- 
cantly more variable in ^? r 
crude-protein content 
than either the hybrids 
or Hard Federation. 
In 1924, at Bozeman, 
Moccasin, and Havre, 
bulk grain from nursery 
rows of F 3 strains and 
parent checks from the 
three stations was an- 
alyzed in duplicate for 
crude-protein content. 
Grain from the poorer 
yielding rows at Mocca- 
sin was not saved. The 
grain from all but one 
of each of the parent 
check rows also was 
discarded, so complete 
results from that station 
were nol obtained. The 
frequency data in half 
per cent frequency clas- 
ses are given in Table 
47 and are shown graph- 
ically in Figure 12. 
Figure 12 shows that 
the crude-protein con- 
tent increases at the 
stations in their order 
at Moccasin, Bozeman, 
and Havre, this being 
the reverse order for the 
stations as to yield. 
The Bozeman F 3 data show that the hybrids and also the Marquis 
parent are extremely variable. This is partly the result of soil 
variation. Two sections in the nursery, comprising about 15 rows 
each, were much lower in crude-protein content of the grain pro- 
duced than the remainder of the nursery. Probably a lacE of avail- 
able nitrates in the soil of these two sections resulted in " yellow- 
berry ' ; wheat with a lower crude-protein content. At this station 
the F 3 hybrids averaged practically the same as Hard Federation 
in crude-protein content and 0.4 per cent less than Marquis. 
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t: 
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Fig. 12.— Frequency distribution of F3 hybrid wheat strains 
and the range of variation of the Marquis and Hard Federa- 
tion parent checks, together with their average crude-protein 
content at Moccasin, Bozeman, and Havre, Mont., in 1924 
