Feb. 9, 1924 
Effect of Fertilizers on Stem Rust of Wheat 
35 7 
The size and position of the plats and the rate of application of fertilizers 
were exactly the same as in 1915. (See Table VI.) 
The hybrid (No. 5 X 2223), used in place of Iumillo, was a cross between 
a durum, Kubanka, C. I. No. 2094, and a common hard red spring 
variety, Preston, C. I. 3328. It was a fixed type, in the F 9 generation, 
originated by Freeman and Johnson. The average amount of stem 
rust on the hybrid in the Minnesota rust nursery from 1912 to 1916 was 
30 per cent. It is slightly more susceptible, therefore, than Iumillo. 
Both varieties were sown on May 13, which is rather late for the dis¬ 
trict. However, the spring was late. The temperatures were abnor¬ 
mally low during April, May, and June, while the precipitation was 
abnormally high. During July and August, however, the conditions 
were reversed. These abnormal climatic conditions undoubtedly af¬ 
fected the development of stem rust, the date of maturity of the plants, 
and the yield. The results obtained, as well as the plan of the experi¬ 
ment, are shown in Table VI. Figure 3 shows the results in the seven 
plats of the series receiving 2,000 pounds of acid phosphate. 
Table VI .—The disposition of the commercial fertilizer plats and the percentages of stem- 
rust infection on Haynes Bluestem wheat and the hybrid , and the degree of drying and 
yield in bushels per acre of Haynes Bluestem in igi6 on commercial fertilizer plats on 
University Farm, St. Paul , Minn. 
Fertilizer. 
Fertilizer, kind and amount (pounds) 
per acre. 
Infection, drying, and yield. 
Amount 
Sodium nitrate. ; 
i 
Potassium sul¬ 
phate. 
Kind. 
per 
None. 
acre. 
1,000 
500 
250 j 
1,000 
500 
250 
Percentage of stem rust, Haynes 
\ 
| 
t 
Blustem. 
' Pounds . 
65.0 
40 
65.0 
36 
68.0 68.0 
70.0 
43 
68.0 
67.0 
40 
Percentage of stem rust, hybrid.... 
40 j 
43 
43 
Percentage of drying, Haynes Blue¬ 
stem. 
2,000 
80 
< 
80 
60 ; 
40 
20 
40 
40 
Bushels per acre, Haynes Bluestem.. 
0.6 
0.7 
i 
2.71 
4 
7.2 
2.8 
4-7 
Bushels per acre, hybrid. 
. 6.6 
6*o 
7.8, 
i ! 4-3 
l8.8 
18.6 
16.8 
Percentage of stem rust, Haynes 
i 
Bluestem. 
' 65 
40- 
66+ 
38 
66+ 
40 
66 
70 
43 + 
70 
43 
70 
43 
Percentage of stem rust, hybrid. 
42 
Percentage of drying, Haynes Blue¬ 
. 
1,000 
80 
60 
40 
40 
40 
40 
stem. 
< 
Bushels per acre, Haynes Bluestem.. 
0.6 
0-5 
1.0 
i -3 
4.6 
i -7 
3-5 
Bushels per acre, hybrid. 
a 
. 5-2 
6.9 
7-5 
13-7 
18.6 
17.4 
17.9 
8 
Percentage of stem rust, Haynes 
f & 
a. 
Bluestem. 
' 66 
66+ 
41 + 
67 
42 
69 
43 + 
70 
45 
70+ 
45 
70+ 
45 
Percentage of stem rust, hybrid 
0 
45 
Percentage of drying, Haynes Blue¬ 
! ^ 
500 
stem . i 
60 
80 
80 
40 
40 
40 
40 
Bushels per acre, Haynes Bluestem. 
o -3 
o -5 
0.7 
1.4 
2.7 
i -7 
2.8 
Bushels per acre, hybrid.! 
* j 
7-4 
9.6 
9 * 1 
14.6 
20.3 
13.0 
19.4 
Percentage of stem rust, Haynes 
Bluestem. 
67 + 
65 
67+ 
70 
7 i 
70 
70+ 
Percentage of stem rust, hybrid. 
Percentage of drying, Haynes Blue¬ 
None. 
43 
42 
42- 
43 + 
45 
43 + 
44 
stem. 
80 
60 
60 
40 
1.8 
40 
2.2 
40 
1.4 
40 
2.8 
Bushels per acre, Haynes Bluestem.. 
o -5 
o -5 
0.7 
Bushels per acre, hybrid. 
. 7.7 
10.0 
8.1 
16.1 
16.8 
i 
11.2 
16.7 
1 
