TESTS OF CORN VARIETIES ON THE GREAT PLAINS. 9 



Since small differences are of little importance in judging the 

 value of different varieties, the varieties are divided into three 

 classes according to yield for each year and the result is shown in the 

 last three columns of the summary tables. Class 1 is made up of 

 varieties yielding above the average; class 2 of varieties of about 

 average yi eld, and class 3 of varieties yielding less than the average. 

 In calculating yields, 70 pounds of dry ears are used for 1 bushel. 



TESTS AT HUNTLEY. 



The tests at Huntley, Mont., have been made under irrigation. 

 Three years' results are available. In 1912 the test contained 6 

 varieties; in 1913, 7 varieties; and in 1914, 11 varieties. Each 

 variety unit was composed of two rows; in 1912 and 1913 these rows 

 were 132 feet long and 3J feet apart, making an area of about one- 

 forty-seventh acre per plat; in 1914 the rows were 170 feet long and 

 3§ feet apart, making the plats one thirty-fifth acre in area. 



In 1913 and 1914 the variety plats were alternated with check 

 plats planted to a common variety, and the series was repeated three 

 times. In 1913 the check plats were planted to Minnesota 13, and 

 in 1914 to Northwestern Dent. The seed was drilled in the rows, and 

 the plants later thinned to one about every 18 inches. The yield in 

 pounds of ears for each variety and check plat and the total yield of 

 each variety are shown in Table II. Check plats are totaled in 

 groups of threes, to correspond with the total yields of varieties. In 

 1913 there were large differences in yields of replicate plats of the 

 same variety and between the yields of check plats. The test for 

 that year has little value except as the results corroborate those of 

 other years in indicating good varieties. In 1914 the differences 

 were smaller between replicate plat yields and the results were more 

 reliable. 



The yields in bushels per acre, the increase of the variety over 

 adjacent checks, and the rank and class of each variety according to 

 yield are shown in the summary of Table II. For 1912 the varieties 

 are ranked according to actual yield. For 1913 and 1914 the varieties 

 are ranked according to the amount by which the average yield of 

 the three plats of each variety exceeds the average yield of the six 

 check plats adjacent to them. The varieties which have yielded 

 relatively high in all tests at Huntley are Northwestern Dent and 

 U. S. Selection 133. 



6827°— Bull. 307—15 2 



