EXPERIMENTS Vv^ITH 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 rainfaU 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 rainfaU 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. 



Alti- 

 tude. 



Precipitation (inches). 



Annual. 



1913 



1914 



1915 



18.52 



16. 10 



34. 85 



16.05 



15. .58 



25.00 



16.80 



11.60 



18.32 



12.53 



11.70 



21.02 



12.46 



17.52 



23.29 





14. -50 



24.89 



19.82 



17.80 



21.96 





17. 43 



17.55 



15. 27 



18.47 



14.32 



11.93 



22.74 



20.53 



14.96 



15.67 



20.68 



Aver- 



Seasonal.i 



Aver- 

 age. 



North Platte, Nebr. 



Akron, Colo 



Archer, Wyo 



Newell, S. Dak 



Highmore, S. Dak. . 



Eureka, S. Dak 



Edgeley, N. Dak... 

 Langdon, N. Dak... 

 Williston, N.Dak.. 

 Dickinson, N. Dak. 

 Moccasin, Mont 



Feet. 

 3,000 

 4,560 

 6,027 

 2,950 

 1,890 

 1,884 

 1,468 

 1, 615 

 1,875 

 2,453 

 4,228 



23.16 

 18. 88 

 15. .57 

 15. 08 

 17.76 

 19.70 

 19.86 

 17.49 

 16.12 

 18-40 

 17.10 



9.02 

 6.81 

 9.26 

 5.68 

 8.59 



.06 



5.95 

 5.43 

 9.32 



8.12 

 10.67 



8.52 



7.03 

 11.98 



9.80 

 13. 06 



7.42 

 12.00 

 18.84 



9.38 



19. .56 

 14.17 

 12.69 

 15.83 

 16.40 

 12.45 

 13. 88 

 9.15 

 7.23 

 14.41 

 11.06 



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 Jime. 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 



