22 



BULLETIN 618, U. S. DEPARTMENT OF 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 Agrieullural Experiment Station.] 



Class, group, and variety. 



Durum: 



Kubanka — Kubanka 



Common: 



Crimean (winter) — Turkey 



Preston — Early Java 



Fife— Glyndon (Minn. No. 163) 



Bluestem — Haynes (Minn. No. 169).. 



39.7 

 25.1 



Yield per acre (bushels). 



37.4 

 20.5 



1908 



14.3 



37.6 

 15.7 

 17.2 



8.7 



14.5 



27.7 

 26.5 

 21.3 

 23.0 



1910 



34.5 



30.0 

 36.7 

 41.6 

 38.3 



Average. 



3 years, 



1908 to 



1910. 



21.1 



31.8 

 26.3 

 26.7 

 23.3 



5 years, 



1906 to 



1910. 



34.5 

 24.9 



2.7 



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 qualit} 7 . 

 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 outyiclded 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 



