6 BULLETIN 1045, U. S. DEPARTMENT OF AGRICULTURE. 



silage per acre. Sunflowers were not grown again at Hays until 

 1920. The rainfall was fairly abundant that year, and the general 

 crops were good. Sunflowers suft'ered from rust and insects and again 

 made a very poor showing in comparison with the sorghums. 



At Akron, Colo., where the altitude is greater than at Hays, Kans., 

 sunflowers were tested in 1911 and 1912. Only seed yields were ob- 

 tained in those years, but the growth was good and insects gave little 

 trouble. The estimated total crop was about three-fourths that of the 

 best varieties of forage sorghums. 



At Amarillo, Tex., sunflowers were grown in 1911, 1912, and 1913. 

 The first two years the crop was fairly good, but the yield was hardly 

 more than half that of the sorghums. In 1913 the crop was almost 

 entirely destroyed by insects. In the semiarid region of the southern 

 Great Plains the value of sunflowers as a silage crop is sure to be 

 limited by the presence of numerous insects which attack the plant. 



The Montana Agricultural Experiment Station made some tests of 

 sunflowers on dry-land farms in 1918 (4^, p. 9). The average yield 

 of silage on 13 different farms in eight counties was 10.3 tons per 

 acre. There was no basis for a comparison of this yield of sunflowers 

 with that of corn grown under similar conditions. The conclusion 

 at the Montana station, however, was that considering the low sea- 

 sonal rainfall the yield obtained was quite satisfactory and "that 

 sunflowers are promising dry-land forage producers." This is per- 

 haps true in Montana, where the temperatures are low during the 

 growing season and sorghum and long-season varieties of corn can 

 not be grown. 



Sunflowers were grown for ensilage in 1920 at the United States 

 Sheep Experiment Station near Dubois, Idaho,' at an elevation of 

 5,700 feet, on the range land of the station by dry-land farming 

 methods. The land is of lava-rock formation, and the area available 

 for cultivation is limited. Although the annual precipitation is about 

 16 inches, it was so dry m 1920 that wheat on the farmed lands adja- 

 cent to the sheep reserve was a total failure. Regardless of this fact, 

 the sunflowers yielded between 4^ and 5 tons of ensilage per acre. 



To obtain a maximum crop of sunflowers by dry-land farming Mr. 

 McWhorter advises the following procedure : 



(1) Summer fallow. Plow the land the previous spring. Keep the plowed 

 area free from weeds and covered by a dust mulch throughout the summer and 

 fall. 



*The work at this station is conducted by the Bureau of Animal Industry of the 

 United States Department of Agriculture. Mr. V. O. McWhorter, who is in immediate 

 charge of the station, has kindly furnished, through Mr. D. A. Spencer, senior animal 

 husbandman in sheep and goat investigations, a preliminary statement of the results 

 obtained with sunflowers. All future statements in this bulletin regarding work at the 

 Dubois station are based on this report. 



