EXPERIMENTS WITH MARQUIS WHEAT. 
17 
and at two others during the last two years of this period. The sta- 
tions are as follows : North Platte, Nebr. ; Akron, Colo. ; Archer, Wyo. ; 
Newell, Highmore, and Eureka, S. Dak.; Edgeley, Langdon, Willis- 
ton, and Dickinson, N. Dak. ; and Moccasin, Mont. The location of 
these 11 stations and the results of the varietal experiments are shown 
graphically in figure 6. By means of graduated columns the average 
yield of Marquis wheat is shown with that of the leading variety in 
each of several groups of wheat grown commercially in these States. 
The same data will be found in Tables IX to XIX, inclusive. 
The climate of this section is generally classed as semiarid. Table 
VIII shows the altitude of each station and the records of annual 
and seasonal rainfall during the three years, 1913 to 1915, inclusive, 
when the varietal experiments were in progress. In the three years 
under discussion the average annual rainfall has varied between 15 
and 20 inches at all these stations except North Platte, Nebr. The 
higher average at that station is due entirely to the enormous pre- 
cipitation of the year 1915. In general, the annual rainfall decreases 
in passing westward across this section. The altitude steadily 
increases from east to west, varying from 1,000 or 1,500 feet on the 
eastern border to 6,000 feet in eastern Wyoming and Colorado. 
Table VIII. — Altitude and annual and seasonal precipitation at 11 experiment stations 
in the semiarid northern section of the Great Plains area. 
Station. 
North Platte, Nebr. 
Akron, Colo 
Archer, Wvo 
Newell, S. 'Dak 
Highmore, S. Dak.. 
Eureka, S. Dak 
Edgeley, N. Dak... 
Langdon, N. Dak... 
Williston, N. Dak.. 
Dickinson, N. Dak. 
Moccasin, Mont 
Alti- 
tude. 
Feet. 
3,000 
4,560 
6,027 
2,950 
1,890 
1,884 
1,468 
1,615 
1,875 
2, 453 
4,228 
Precipitation (inches). 
Annual. 
1913 
18. 52 
16.05 
16.80 
12.53 
12.46 
19. S2 
15.27 
11.93 
14.96 
1914 
16.10 
15.58 
11.60 
11.70 
17.52 
14. 50 
17.80 
17.43 
18.47 
22.74 
15.67 
1915 
Aver- 
34.85 
25.00 
18.32 
21.02 
23.29 
24.89 
21.96 
17. 55 
14.62 
20.53 
20.68 
23.16 
18.88 
15.57 
15.08 
17.76 
19.70 
19.86 
17.49 
16.12 
18.40 
17.10 
Seasonal. 1 
1913 
9.02 
6.81 
9.26 
5.68 
8.59 
5.95 
5.43 
9.32 
1914 
8.12 
10.67 
8.52 
7.03 
11.98 
9.80 
13.06 
7.42 
12.00 
18.84 
9.38 
1915 
19.56 
14.17 
12.69 
15.83 
16.40 
12.45 
13.88 
9.15 
7.23 
14.41 
11.06 
Aver- 
age. 
12.23 
10.55 
10.16 
9.51 
12. 32 
11.12 
12.00 
8.27 
8.39 
12.89 
9.92 
1 The record for seasonal precipitation includes the four months of April, May, June, and July at all 
stations except North Platte, Nebr., and Archer, Wyo. At North Platte the record is for the four months 
of March, April, May, and June. At Archer the record is for the five months of April, May, June, July, and 
August. 
Crop production is governed largely by the quantity and distribu- 
tion of the annual precipitation. Reference to Table VIII shows that 
one-half to two-thirds of the total comes during the growing season 
of four months. Wind movement is fairly constant and summer 
temperatures rather high. These factors cause loss of water by 
evaporation. Hot winds and hail sometimes occur. Wet, warm 
weather in midsummer sometimes promotes epidemics of rust. 
50401°— Bull. 400—16 3 
