FACTORS FOR YIELD AND QUALITY OF SPRING WHEAT 
29 
Three notes were taken for dates of ripening on F 3 rows at each 
station: (1) First ripe, (2) 50 per cent ripe, and (3) fully ripe. From 
a careful study of these notes it appears that fully ripe is the most 
definite and therefore the most valuable. The frequency data for 
date when fully ripe are shown for the three stations in Table 29 
and graphically in Figure 4. 
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Fig. 4.— Frequency distribution of F 3 hybrid wheat strains and the range of variation of the 
Marquis and Hard Federation parents, together with their average dates of last ripening at 
Havre, Moccasin, and Bozeman, Mont., in 1924 
The data show that most of the F 3 hybrids are intermediate be- 
tween the parents, with the early and late extremes of the parents 
exceeded only by a few hybrid strains. The date of fully ripe on the 
F 3 row basis shows a greater variability for the hybrids in comparison 
with the parents than did the date of ripening on individual F 2 
plants. Different rows of the parents, however, vary considerably 
at all stations for date of fully ripe. Figures 2 and 4 show that the 
