A Study oe Colorado Wheat 
45 
servation that the Red Fife resists the action of nitrogen in pro¬ 
ducing lodging or weakness of the straw. I have figures for Red 
Fife and Kubanka, showing the effect of fertilizers upon the amount 
of silicon in the upper portion of the stem, but none for Defiance. 
SILICON IN THE TOP INTERNODE OF THE STEM. 
Red Fife 
Kubanka 
Date of Harvest 
Fertilizer Lbs. per Acre 
Si Percent 
Si Percent 
31 July, 1914 
120 nitrogen 
0.535 
0.543 
31 July, 1914 
80 phosphorus 
0.559 
0.612 
31 July, 1914 
150 potassium 
0.509 
0.826 
31 July, 1914 
None 
0.508 
1.174 
SILICON IN 
DIFFERENT PARTS OF STRAW. 
Date of 
Harvest 
Variety 
Part of Plant 
Fertilizer per Acre 
Silicon 
Percent 
6 
Aug,, 1914 
Kubanka 
Leaves 
120 pounds nitrogen 
2.846 
6 
Aug., 1914 
Kubanka 
Leaves 
None 
3.520 
31 
July, 1914 
Kubanka 
Top of stem 
120 pounds nitrogen 
0.543 
31 
July, 1914 
Kubanka 
Top of stem 
None 
1.174 
6 
Aug., 1914 
Kubanka 
Middle of stem 
120 pounds nitrogen 
0.381 
6 
Aug., 1914 
Kubanka 
Middle of stem 
None 
0.658 
6 
Aug., 1914 
Kubanka 
Bottom of stem 
120 pounds nitrogen 
0.402 
6 
Aug., 1914 
Kubanka 
Bottom of stem 
None 
0.684 
IThis variety, Kubanka, was chosen for these determinations 
because it seemingly responds to the effects of nitrogen in regard 
to the silicon to a less degree than the Defiance and to a greater 
one than the Red Fife and we assume the results to be of more 
general application than those obtained with the other varieties. 
These results show that an increase in the supply of available 
nitrogen suppresses the amount of silicon contained in these differ¬ 
ent portions of the plant. 
There is some difference shown in the relative amounts of 
soluble and insoluble silicon in plants grown with and without 
addition of nitrogen to the soil. It seems to be the fact that the 
application of sodic nitrate suppresses the amount of silicon soluble 
in water to a greater extent than it does the insoluble silicon. This, 
however, is only a tentative statement based on the work that has 
so far been done. 
The distribution of the ash in the different parts of the plant, 
the extent and manner in which it is affected by the application of 
nitrates has been studied in part, but not thoroughly. The results 
obtained, however, agree with those already presented, indicating 
that the effect of the nitrogen upon the intake of inorganic constit¬ 
uents by the plant is very strongly modified. 
