350 
Journal of Agricultural Research voi. xxvii, no. 6 
which had not been fertilized with acid phosphate. This seemed to be 
quite natural, as the fertilized plants were small and unthrifty. They 
had been injured by excessive fertilization, but, even then, stem rust 
developed fairly well. 
FIELD EXPERIMENTS WITH COMMERCIAL FERTILIZERS IN 1915 
The field plats in 1915 were laid out on University Farm on rather 
heavy Hempstead loam soil 8 which had grown alfalfa for the preceding 
15 years. Each plat was 1 square rod in extent and all were separated 
from each other by 3-foot alleys. The general arrangement is shown in 
Table III. The fertilizers were applied as indicated under “Experi¬ 
mental methods/’ 
N N 
P£GC£HT /OOO SOO 
2 fO /OOO 
h /r 
SOO 2SO 
/oo 
90 
80 
70 
6° 
So 
4o 
3o 
2o 
/o 
Fig. 2.—Graph showing the percentages of stem rust on Haynes Bluestem and on Iumillo and the per¬ 
centage of lodging and acre yield in bushels (31 bushels=100 per cent) of Haynes Bluestem grown in 
plats which had received acid phosphate at the rate of 2,000 pounds per acre plus different amounts, 
in pounds, of sodium nitrate (N) and potassium chlorid (K) in the commercial fertilizer experiments 
in 1915 on University Farm, St. Paul, Minn. 
--rust on Haynes Bluestem. 
-lodging of Haynes Bluestem. 
-- — — • - yield of Haynes Bluestem. 
----rust on Iumillo. 
BUST . 
OAT 
VS/ATC* / 
—- 
• 
5. 
/ 
# 
A/ 
? 
of ,»• 
\o 
%*T\| 
% 
% 
• 
- lyi - 
s 
oUSl 
/ ^ 
•A 
% 
ft 
* 
U! 
! 
§ 
On May 6, Haynes Bluestem, C. I. 2874, was sown on half of each plat; 
and Iumillo, C. I. 1736, was sown on the other half. Haynes Bluestem is 
a hard red spring wheat, one of the best milling wheats grown in that 
region. But it is extremely susceptible to black stem rust, as is indicated 
by the fact that this variety has had an average infection of 70 per cent 
in the Minnesota rust nursery during the past eight years. Iumillo is a 
highly resistant durum on which the average percentage of rust in the 
Minnesota rust nursery from 1910 to 1920 was 10 per cent. 
The seed was sown on May 6. Differences in the character of growth 
of the wheat in the different plats became apparent soon after the plants 
came up. The heaviest stand was on the nitrate plats, and the density 
of stand was in direct proportion to the amount of nitrogen applied. 
The plants were very succulent and soon began to lodge rather badly. 
The plants in the nitrogen plats also were a much darker green than 
those in the other plats. There was very little difference in the general 
* See description of this soil under “Methods." 
