24 BULLETIN 30, IT. 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 

 vield. These variations occurred each vear and, as shown in Table X 

 the same facts are true in the averages of the four } T ears. An explana- 

 tion of this behavior probably lies hi 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 per cent. 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 5-3 T ear period 

 was then determined. The comparative dates of heading for all 

 varieties are presented hi 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 w.as 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. 



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 

 farm- in the Great Basin. 



