12 BULLETIN 430, U. S. DEPARTMENT OF AGRICULTURE. 



INTERPRETATION OF EXPERIMENTAL RESULTS. 



The interpretation of the results obtained from plat experiments is 

 difficult. This is due to the large number of factors which must 

 be considered in determining the relative value of different varieties 

 or different cultural methods. Generally speaking, the variety that 

 gives the highest average yield of good quahty in a period of several 

 years is the one that should be grown. It is really quite difficult to 

 obtain a variety that is consistently a high yielder and also is high 

 in quality. Variations in soil and seasonal and annual variations in 

 climate have a great influence on crop production in dry-land areas. 

 AU these factors must be thoroughly studied, in order that rehable 

 conclusions may be drawn. The experiments at the Cheyenne 

 Experiment Farm have been under way for only three years. This 

 is too brief a period to give the needed long-time average of yields 

 or to permit sufficient study of soil and cUmatic variations. 



EXPERIMENTS WITH WHEAT. 



At Archer, experiments with winter and spring varieties of wheat 

 have been conducted in field plats and nursery rows. Most of the 

 work, however, has been done on field plats. Wheat is the leading 

 crop in southeastern Wyoming. Spring and winter varieties are 

 grown on about equal acreages. More work has been done at 

 Archer with wheat than with any other cereal. 



WINTER WHEAT. 



Experiments with winter wheat have included varietal, rate-of- 

 seeding, and date-of -seeding experiments. The work at Archer is 

 relatively new. Therefore Httle has been done in the improvement 

 of crop varieties. The work has been confined for the most part 

 to the testing of varieties known to be the most promising for the 

 dry-land districts. 



VARIETAL EXPERIMENTS. 



The varietal experiments with winter wheat on the Cheyenne 

 Experiment Farm have included for the most part the hard, red win- 

 ter varieties of the Crimean group. Seven varieties have been grown 

 for three years, 1913, 1914, and 1915, while eight additional varieties 

 have been grown for two years, 1914 and 1915. The annual and 

 average yields of winter-wheat varieties are presented in Table VI. 



In 1913, seven winter- wheat varieties and strains were grown in 

 duplicate tenth-acre plats on sod that was broken in August, 1912, 

 double disked twice, and harrowed. The plowing was poorly done 

 and the seed bed was rather rough. The seed was sown on October 5, 

 1912. The plants emerged on October 25, but made little growth 

 before winter. The stands obtamed were rather thin, but tillered 



