Feb. 9. 1924 
Effect of Fertilizers on Stem Rust of Wheat 
365 
Results from Second Series—Quinn Farm 
The second series was laid out on rather light, Hempstead clay-loam 
soil and consisted of 32 plats. The general plan was similar to that 
followed on University Farm, except that on the Quinn farm certain 
combinations were made between sodium nitrate and potassium chlorid, 
and other combinations of sodium nitrate, potassium chlorid and acid 
phosphate. The plats were sown to Marquis and the hybrid, as in the 
first series. The disposition of the plats, the rate and kind of fertilizer 
applied to each, the percentage of stem rust on both varieties, and the 
yield for Marquis are given in Table XI. 
Table XI. —The disposition of the fertilizers applied, the percentages of stem rust on 
Marquis and the hybrid, and the yields in bushels per acre of Marquis in IQIJ in the 
commercial fertilizer plats on the Quinn farm, St . Paul, Minn. 
Infection and yield. 
Fertilizer. 
Fertilizer, kind and amount (pounds) per acre. 
Kind. 
Amount 
per acre. 
Sodium nitrate. 
None. 
Sodium 
nitrate. 
1,000 
500 
250 
500 
500 
Pounds. 
Percentage of stem rust, Marquis 
[80 
28 
12 
5 
6- 
5 “ 
IO 
9 
Percentage of stem rust, hybrid. 
2,000 
<20 
10 
2 
I 
2 
I 
I 
1 
Bushels per acre, Marquis. 
I24.2 
43-9 
27.6 
14-3 
2 5 - 1 
22.3 
20.2 
20.0 
Percentage of stem rust, Marquis 
<6 
[76 
65 
9 
8 
8 
8 
12' ; 
11 
Percentage of stem rust, hybrid. 
& 
1,000 
<20 
8 
3 
1 
1 
1 
2 
2 
Bushels per acre, Marquis. 
Oh 
8 
133-4 
29.6 
33 - 6 
30.2 
30.0 
3 i -7 
42,9 
38.1 
Percentage of stem rust, Marquis 
’ £ 
10 
9 
8 
7 
7 
7 
10 
11 
Percentage of stem rust, hybrid. 
TJ 
♦ rH 
5 °° 
‘ 3 
1 
I 
1 
1 
1 
' 5 -' 
3 
Bushels per acre, Marquis. 
U 
< 
.42.7 
37-8 
29.O 
21.9 
23.6 
23.2 
40.5 
39-6 
Percentage of stem rust, Marquis 
f 11 
11 
IO 
10 
10 
10 
27 
18 
Percentage of stem rust, hybrid. 
None. 
| 4 
1 
I 
1. 
1 
2 
20 
22 
Bushels per acre, Marquis. 
L 33 - 7 
42.7 
37-4 
29.0 
30 *i 
28.4 
37-6 
16.4 
500 
250 
500 
250 
Potassium chlorid. 
Fertilizer, kind and amount (pounds) per acre. 
It was pointed out in the discussion of results on University Farm that 
the increased percentage of rust on a few of the plats to which sodium 
nitrate had been applied was due to delayed maturity arid not to an 
increased degree of susceptibility. This fact is illustrated clearly in 
Table XII. Even with the slight difference in these plats, it is apparent 
that in these experiments the effect of the fertilizers on the susceptibility 
of the wheat to attacks by stem rust is too small to be significant. 
The percentages of stem rust for the various plats in the column headed 
“ Percentage of rust, August 10,” it will be noted, are very uniform. For 
the hybrid they run, 1, 2, 2, 5, 2, 4, and 1 per cent, respectively, for plats 
22, 30, 23, 31, 24, 32, and 28, respectively. This same series ten days 
