542 
Journal of Agricultural Research voi. xxiii, No. 7 
Tabu} XX .—Correlation coefficients for yield of flour and loaf volume 
Kind of wheat. 
Number of Coefficient of correla- 
samples. tion. 
Commercial varieties: 
North Dakota spring wheats 
Montana spring wheats. 
Minnesota spring wheats.... 
Montana winter wheats.... 
Ohio winter wheats. 
Minnesota winter wheats. .. 
Pure strains: 
North Dakota spring wheats 
Minnesota spring wheats.... 
99 
34 
202 
9 i 
29 
43 
— o. 0900 ±0. 0672 
. 1425^ • 11 33 
. 15241b . 0464 
— -o53o± .0705 
— . I440± . 1227 
• 339 2 ± -091° 
56 - .39201b .0763 
48 .12831b . 0958 
GUADIN AND LOAF VOLUME 
As already stated, the gliadin content has been suggested as a factor 
determining strength in wheat flour. In Table XXI are given data indi¬ 
cating the relationship between gliadin and strength as measured by loaf 
volume. The correlation for the North Dakota wheats, commercial va¬ 
rieties, is again negative, that for the Colorado is positive, but both are 
hardly significant as their value is less than three times their probable 
error. The remaining correlations are positive and some of them very 
high, ranging from o.38i5±o.c>96o for the Kansas wheats to o.7455± 
0.0598 for the North Dakota spring wheats, pure strains. 
Table XXI .—Correlation coefficients for gliadin and loaf volume 
Kind of wheat. 
Number of 
samples. 
Coefficient of correla¬ 
tion. 
Commercial varieties: 
North Dakota spring wheats. 
113 
48 
36 
16 
25 
—0. i7i8±o. 0616 
. 0308± . 0973 
• 38 i 5 ± -° 9 6 ° 
. 6304± . 1017 
• 7455 ± -0598 
Colorado spring wheats. 
Kansas winter wheats. 
Pure strains: 
Ontario spring wheats. 
North Dakota spring wheats. 
DRY GLUTEN AND GLIADIN 
Gliadin is one of the constituents of gluten, and a close association 
between these two values is to be expected. The data in Tables XXII 
and XXIII are rather meager and indicate a positive correlation, the 
coefficients ranging from 0.3941 ±0.1058 for the Ohio wheats, which is 
rather low, to 0.9352±0.0212 for the Ontario wheats. 
