24 BULLETIN 30, U. S. DEPARTMENT OF AGRICULTURE. 
yield, a thick stand resulting in a high yield, but in just as many 
cases a relatively thin stand would result in an equally high yield. 
In other cases a thick stand would be followed by a relatively low 
yield. ‘These variations occurred each year and, as shown in Table X, 
the same facts are true in the averages of the four years. An explana- 
tion of this behavior probably lies in the fact that where the stand 
is thin the plants tiller more than they do when they are crowded in 
a thick stand. This point will be discussed more in detail in con- 
nection with the presentation of the observations made in the nursery 
tests. 
In order to allow a more direct comparison of the stands of the. 
winter-wheat varieties, the comparative stand is given in percentages 
in column 5 of Table X._ It was computed in this manner: The 
total average number of plants per acre for all varieties (113,000) 
was used as 100 percent. Then by dividing the number of thousands 
of plants per acre for any one variety by 113 the comparative stand 
of that variety was obtained. 
Average date of heading.—The date on which any variety was fully 
headed was noted each year. The average date for the 5-year period 
was then determined. The comparative dates of heading for all 
varieties are presented in column 6 of Table X. It will be noted 
that there was little difference among varieties in this regard. 
Average date of ripening.—When the kernels of any variety were 
in the hard dough stage it was considered ripe. The varieties were 
watched closely each year and the date of ripening was noted. The 
average dates for the 5-year period are given in column 7 of Table X. 
Here again it will be observed that little difference existed among 
the varieties. It appears that available soil moisture is the domin- 
ating factor in the control of cereal crops at Nephi and that all 
varietal differences are subsidiary to it when length of growing 
period is concerned. By July 1 the available soil moisture to a 
depth of 3.5 to 4 feet is sufficiently exhausted to check the growth 
and hasten maturity. Thus the varieties all ripen within a limit 
of a very few days. 7 
Average height.—In each season the height of the crop was deter- 
mined by taking the average of several measurements made in the 
plat. Each measurement was made from the ground to the tip of 
the heads, but not including the beards in bearded varieties. 
The average height of the winter wheats at Nephi, as shown in 
Table X, is 27 inches. This is a low stature when compared with 
that of wheats grown in the more humid districts, and some diffi- 
culty is often experienced in harvesting the crops with a binder. 
The length of straw is not an important factor, however, where the 
header is used in harvesting, as it is almost exclusively on the dry 
farms in the Great Basin. 
