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 suffered 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, 4 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 in 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 4J 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. 0. 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 tbe results 
obtained with sunflowers. All future statements in this bulletin regarding work at the 
Dubois station are based on this report. 
