June 2,1923 
Sunflower Investigations 
779 
TIME FOR CUTTING 
In considering the proper stage for cutting sunflowers in Idaho, either 
of the last two stages could be profitably used for silage, as there is little 
material difference in the analyses for the two stages in either the 1920 or 
1921 crops. In some sections where sunflowers mature slightly more than 
in the Palouse country of Idaho, it might be profitable to cut them a 
little later than those of the last stage included in this investigation. 
In any event, cutting should not be delayed much beyond the last stage 
studied, for then the stalks become hard and woody and a silage is obtained 
which is unpalatable and not relished by the stock. 
The moisture content of the sunflower plant grown in the last two 
stages is approximately 80 per cent. This percentage of moisture is 
slightly higher than is usually desired in a crop intended for the silo. 
When the green material contains too much moisture, there is danger of a 
loss of considerable juice, which means a loss of soluble food nutrients. 
In crops containing a high sugar content, a high moisture content means 
also a high acid content. Shaw and Wright state that ''a high moisture 
in the plant is usually associated with high acid silage.” This holds true 
for corn silage, but an inspection of Table I shows that it does not always 
hold true for sunflowers. In the case of sunflowers a high moisture 
content results chiefly in a loss of soluble food nutrients in the juice. 
If the sunflowers seem to have too high a moisture content when cut, 
this can be materially decreased by allowing the plant to wilt for a short 
period. Blish, of Montana, has shown that excellent silage resulted 
when sunflowers were cut and allowed to wilt before siloing until the 
moisture content was 72.24 per cent. A moisture content for sunflower 
silage in Idaho can vary from 70 to 80 per cent, the writers recommending 
approximately 75 per cent as an average. 
distance apart in row 
When the two different distances of planting in the row are considered 
for 1920, it appears that the single plants growing 36 inches apart in the 
row rank slightly higher in food nutrients than the sunflowers planted 
every 4 to 8 inches. The analyses of the sunflowers, and the sunflower 
silage, both show a slight advantage over the closer plantings. The 
yield must be considered in deciding which system of planting is most 
profitable. The yields for the two spacings determined by the agronomy 
department showed 22.32 tons for the 36-inch spacings and 20.23 tons 
for the 4-inch to 8-inch spacings. However, because of the difference 
in the contour of the land upon which the sunflowers were grown, these 
yields can not be considered as final. 
The yields of sunflowers grown in 1921 show results which are con¬ 
trary to the findings of 1920. The 8-inch spacings gave a higher yield 
than the 42-inch spacings. Under the conditions that existed in 1921, 
very little difference was noted in the yields of the sunflowers drilled 8 
inches apart and the sunflowers planted in hills containing two or three 
stalks. Four stalks in the hill did not yield as well as the hills contain¬ 
ing two and three stalks. 
From the data presented on the two years of sunflowers it is apparent 
that the different climatic conditions, chiefly the proper distribution of 
moisture throughout the life cycle of the sunflower plant, affect the yield 
of sunflowers when planted at different spacings in the row. The results 
vary from year to year in the Palouse country, because of variable 
