22 
BULLETIN 618, U. S. DEPARTMENT OE AGRICULTURE. 
Table VI. — Annual and average yields of one variety of durum wheat and four varie- 
ties of common wheat grown at the Iowa Agricultural Experiment Station, Ames, 
Iowa, during periods of varying length in the five years from 1906 to 1910, inclusive. 
[Data obtained in cooperation with the Iowa Agricultural Experiment Station.] 
Yield 
aer acre 
(bushels). 
Class, group, and variety. 
1906 
1907 
1908 
1909 
1910 
Average. 
3 years, 
1908 to 
1910. 
5 years, 
1906 to 
1910. 
Durum: 
21.4 
39.7 
25.1 
22.5 
37.4 
20.5 
14.3 
37.6 
15.7 
17.2 
8.7 
14.5 
27.7 
26.5 
21.3 
23.0 
34.5 
30.0 
36.7 
41.6 
38.3 
21.1 
31.8 
26.3 
26.7 
23.3 
21 5 
Common: 
Crimean (winter) — Turkey 
34.5 
Preston— Early Java 
Fife— Glyndon (Minn. No. 163) 
24.9 
Bluestem— Haynes (Minn. No. 169)... 
24.1 
19.6 
22.7 
RESULTS AT BROOKINGS, S. DAK. 
According to Table II (p. 15), Brookings is situated on a glacial 
sandy loam at an altitude of 1,636 feet, the greatest elevation of any 
station in the prairie section. The average rainfall, based on a 27- 
year period, is 20.5 inches. The experiments were conducted coop- 
eratively by the South Dakota Agricultural Experiment Station and 
the Office of Cereal Investigations. 
The experiments were begun in 1904 and have continued until the 
present time. Results during periods of varying length in the 13 
years from 1904 to 1916, inclusive, are shown in Table VII and 
graphically in figure 8. 
Brookings lies in the hard spring- wheat belt, and the durum wheats 
should be adapted to the conditions of that locality, though the 
rainfall is a little too high for the development of the highest quality. 
The annual and average yields of five varieties, two durums and three 
representative common wheats, are recorded for a 12-year period. 
The two durums, Arnautka and Kubanka, both in the Kubanka 
group, excel all three common wheats. One of the durums, Arnaut- 
ka, outyields the common varieties by a significant average yield 
of 3.5 bushels per acre. Among the common wheats, Preston out- 
yields Fife and Bluestem by 3.5 and 4.1 bushels, respectively. The 
Marquis variety was grown only during the last four years of the 
experiment. In those years, however, it outyielded all other varie- 
ties of common and durum wheat. The yields of winter wheat of 
the Crimean group have not been obtained consecutively throughout 
this period. In the 10 years, however, in which it was grown it has 
exceeded the Arnautka in yield by an average of 1.8 bushels. 
Eight varieties of durum wheat, all in the Kubanka group, have 
been tested for periods of 5, 9, or 12 years. The Arnautka variety 
has proved best adapted, outyielding the Kubanka in each of the 
