EXPERIMENTS WITH DURUM WHEAT. 
43 
The most striking fact in Table XX is the very close agreement 
of average yields for long periods. The average yields of the five 
durum varieties in the 11-year period range only from 20.1 bushels 
to 21.5 bushels per acre. The yield of Haynes is 15 bushels and of 
Rysting 14.9 bushels in the same period. In the 6-year period, 
1908-1913, inclusive, Preston, Rysting, and Haynes vary only 0.2 
bushel in average yield. 
In the Edgeley district a durum wheat is decidedly the best wheat 
to grow. This conclusion is borne out also by the fact that the 
greatest density of durum production is in that section of the State. 
Among the five varieties tested, Arnautka has proved slightly the 
best adapted, outyielding Kubanka by 1.4 bushels in all 11 years. 
This result is in accord with those obtained at Brookings, S. Dak., 
and Crookston, Minn., discussed in the subhumid prairie section. 
BESULTS AT LANGDON, N. DAK. 
The Langdon substation of the North Dakota Agricultural Experi- 
ment Station is located on a black clay-loam soil at an altitude of 
1,615 feet. The average annual rainfall in a 4-year period has been 
17.9 inches. The substation is operated independently by the North 
Dakota Agricultural Experiment Station, and the results obtained 
have been published in annual reports, from which source they are 
presented here (Stewart, 1910-1914). 
Data are available for only the five years, 1909 to 1913, inclusive. 
These are found in Table XXI, and the principal ones in figure 12. 
The results are all definitely and significantly in favor of the durum 
wheats. 
Table XXI. — Annual and average yields of six varieties of durum wheat and three varieties 
of common wheat grown at the Langdon (N. Dak.) substation during periods of varying 
length in the five years from 1909 to 1913, inclusive. 
CI. 
No. 
Yield per acre (bushels). 
Class, group, and variety. 
1909 
1910 
1911 
1912 
3913 
Average. 
4 years, 
1909 to 
1912. 
4 vears, 
1910 to 
1913. 
5 vears, 
1909 to 
1913. 
Durum: 
Kubanka— 
1494 
1443 
1350 
1349 
1444 
1445 
30.8 
25.2 
29.8 
25.0 
24.2 
16.8 
15.3 
13.6 
12.0 
11.2 
9.6 
9.7 
7.5 
10.7 
8.0 
29.4 
29.6 
25.5 
27.0 
24.2 
27.6 
19.2 
17.1 
17.5 
34.7 
35.7 
32.7 
31.3 
30.7 
24.1 
32.3 
27.2 
27.5 
21.6 
24.3 
21.7 
23.1 
18.7 
21.5 
22.8 
27.6 
26.0 
25.0 
. 23.6 
22.2 
19.6 
""i8.~9" 
18.1 
25.2 
25.6 
23.0 
"23.2 
26.4 
25.7 
24.3 
23.5 
Common: 
Preston — "Velvet Chaff "No 13 
19.4 
19.1 
19.0 
Fife— Glyndon (Minn. No. 163) 
Bluestem— Haynes (Minn. No. 169).. 
L873 
2874 
20.5 
19.4 
19.4 
19.0 
