JOURNAL OF AGRICULTDRAL RESEARCH 
You. XXI Washington, D. C., July 15, 1921 No. 8 
RELATION OE HARDNESS AND OTHER FACTORS TO 
PROTEIN CONTENT OF WHEAT 
Herbert F. Roberts 
University of Manitoba (formerly of the Kansas Agricultural Experiment Station) 
It is well known that hard spring and hard winter wheats are higher 
in protein content than the soft wheats. Since the former are uniformly 
higher in protein content, it has been assumed that the factors for hard¬ 
ness and protein content are correlated. 
As early as 1904 Harper and Peters (2) 1 made the following observa¬ 
tion regarding wheats used in their experiments: 
The dark flinty kernels are distinctly harder than the light starchy ones and con¬ 
tain more protein. 
Snyder (7) reported the analyses for protein of 63 different varieties 
of wheat, in which each variety was divided into two samples, one 
containing only light-colored (starchy) and the other only dark-colored 
(flinty) grains. No hardness test was made directly. The dark kernels 
were found to contain 15.13 per cent protein as compared with 12.76 
per cent for the light-colored kernels. This is a difference of 2.37 per 
cent in favor of the former. 
In another test (8) six different samples of wheat were divided into 
starchy and flinty kernels and analyzed for protein. The flinty kernels 
contained 14.04 per cent of protein and the starchy kernels 12.12 per 
cent. In another lot of 12 varieties the starchy kernels contained on 
the average 12.86 per cent protein and the flinty kernels 14.91 per cent. 
Averaging all of Snyder’s results, there is a difference of 2.11 per cent 
in favor of the flinty kernels. 
Snyder (8) also reported the analyses of starchy and flinty kernels 
of other grains. In all cases the flinty kernels contained the most pro¬ 
tein, the difference being 0.82 per cent for corn, 0.75 per cent for rye, 
and 0.49 per cent for oats. 
Shepard ( 6 ), of the South Dakota Agricultural Experiment Station, 
reported a protein content of 15.6 per cent for durum wheat and 13.68 
per cent for common wheat. 
1 Reference is made by number (italic) to “ Literature cited,” p. 521-522. 
Journal of Agricultural Research, 
Washington, D. C. 
yk 
(s°7) 
Vol. XXI, No. 8 
July 15, 1921 
Key No. Kans. -26 
