36 BULLETIN 618, U. S. DEPARTMENT OF AGRICULTURE. 



The experiments with durum wheat date from 1906. The data 

 are given in Table XV and the principal facts graphically in fig- 

 ure 12. 



The results show that there is little difference in the yielding power 

 of several different varieties under the prevailing conditions at North 

 Platte. The vicissitudes attendant upon grain growing, however, are 

 clearly shown by the yields in the 5-year period, 1912 to 1916, inclu- 

 sive, which are only about half as large as those in the 5-year period, 

 1906 to 1910, inclusive. Comparison of durum yields with those of 

 other wheats can be made only in the second 5-year period. The 

 yield of Turkey is nearly double that of the durum varieties. Mar- 

 quis does not quite equal the yield of the poorest durum and falls 1.5 

 bushels below that of the best durum. Preston is much poorer than 

 Marquis. To summarize, winter wheat of the Crimean group ranks 

 first, while the durums outyield any spring common wheat so far 

 tried. 



The differences in yield between the different durum varieties are 

 scarcely large enough to be significant. The Kubanka group out- 

 yields either Kahla or Velvet Don, and the Gharnovka outyields 

 Kubanka within the group. 



RESULTS AT ARCHER, WYO. 



The Cheyenne Field Station at Archer, Wyo., is located on a fairly 

 sandy loam containing some gravel. The altitude is almost exactly 

 6,000 feet above sea level. The normal rainfall is only 14.2 inches. 

 These records are mostly from Fort D. A. Russell at Cheyenne, 9 

 miles distant, where conditions probably are slightly more favorable 

 than at Archer. The conditions of high altitude and northern lati- 

 tude allow only a short growing season, and this, combined with the 

 low rainfall, makes crop growing somewhat difficult. The experi- 

 ments are conducted by the Office of Cereal Investigations in coopera- 

 tion with the Wyoming State Board of Farm Commissioners. 



The results of experiments conducted with wheat in the four years 

 1913 to 1916, inclusive, or since the establishment of the station, are 

 shown in Table XVI, and the principal results graphically in figure 12. 

 Here, as at Akron, the number of durum varieties is large, no less than 

 14 having been tested during all or a part of this period. Here again 

 there is a close agreement between the yields of the hard red winter 

 wheats and the best durums, the Turkey having a slightly higher 

 yield. The best durum varieties again outyield the Erivan and also 

 the Marquis by small quantities. The Haynes Bluestem is decidedly 

 outclassed by the durums. 



From a study of Table XVI it is evident that no less than five varie- 

 ties of the Kubanka group have outyielded the representatives of the 

 other groups of spring wheat. Tins is true in both the 3-year and the 

 4-year periods, and four of the outstanding varieties are the same in 



