10 
BULLETIN 557, U. S. DEPARTMENT OF AGRICULTURE. 
/e 20 22 2* 2e 23 &o 
TO TO TO TO TO TO TO 
/9.9 2/.3 23.9 2S.9 #7:3 23.9 3/.S 
7 /.S- 
32 
TO 
339 
37.S 
FLOUR YIELD AND WEIGHT PER BUSHEL. 
The value of the " weight per bushel " or " test-weight " determi- 
nation as a rough means of measuring wheat quality has long been 
recognized by the grain trade, and requirements relating thereto are 
made in practically all grading rules. The weight of the measured 
bushel of pure 
wheat is dependent 
upon the specific 
gravity, shape, 
size, and uniform- 
ity of the kernels. 
As usually deter- 
mined, it is affect- 
ed by impurities, 
such as weed 
seeds, dirt, chaff, 
and other grains. 
Grade rules in 
force in a few mar- 
kets provide that 
the determination 
be made on the 
screened sample, 
23 
73 S9 /32 /37 1 93, 
At£SAV02fi Of 3?A?A7f=>L.£3 
23 
Fig. 7. — Diagram showing the relation between the weight 01 ? in Oilier Words, 
per 1,000 kernels and the flour yield of samples of soft red after the 
and hard red winter and hard red spring wheat of the crops 
of 1911, 1912, and 1913. 
larger 
part of the im- 
purities have been 
removed. Generally, however, no such rule is observed. The de- 
terminations reported here were made with the samples after they 
had been cleaned and prepared for milling, and the influence of im- 
purities is reduced to a minimum. It will be found that the figures 
for this reason are a little higher than those ordinarily secured. 
Among the factors causing variation in the test weight are shriv- 
eled or shrunken kernels, the various forms of damage usually sus- 
tained in the field, the moisture content, and varietal differences. 
The last-mentioned factor is unfortunate and detracts from the 
value of the test rather than adds to it, as such variations often 
have little relation to quality. More will be said of this in a fol- 
lowing paragraph. All the other factors mentioned bear a direct 
relation to quality. 
That high moisture content is accompanied by low flour yields has 
been brought out, and as high moisture content is also accompanied 
by low weight per bushel it is apparent that this determination is 
