214 
Explanation of Diagram 1. 
Plats 1, 3, 5, 7, 9, 11, 13, 15, 17, aiul 19, untreated. 
Plats 2, 8, and 14, sprayed every ten days with Bordeaux mixture, full strength, 
from the time the plants appeared above ground until harvest. 
Plats 4, 10, and 16, sprayed every teu days with ammoniacal solution of copper car¬ 
bonate, full strength, from the time the plants appeared above ground until harvest. 
Plats 6, 12, and 18, sprayed every ten days with potassium sulphide solution, 2 
ounces of potassium sulphide to 3 gallons of water, from the time the plants appeared 
above ground until harvest. 
The land was rich bottom, having grown but one previous crop and 
that in 1891. By an accident a part of the field selected was plowed 
early in July. This part fortunately almost exactly coincided with 
plats 3, 4, 7, 8, 13, 14, 17, and 18. Mr. Swingle in commenting upon 
this point says: 
In selecting the field of wheat I did not think of the early plowing a part of it 
received. This, as will be seen further on, had an important bearing on the yield of 
straw and grain. It so happened, however, that the lines running north and south 
and separating the early from the late plowing almost coincided with the lines sep¬ 
arating certain plats. In considering the effect of the treatment, therefore, the 
plats plowed early should be compared with each other and not with those plowed 
late. 
The sprayings were made with a knapsack pump and Vermorel noz¬ 
zle, beginning on October 17 and ending June 13, no soap being used. 
On June 21, Mr. Swingle, acting under instructions from the writer, 
carefully examined the plats and estimated to the best of his ability 
the amount of rust on each. The figures obtained are set forth in the 
following table: 
Table 5. —Showing the per cent of rust on the treated and untreated plats June 21. 
Plat. 
Kind of treatment. 
Per cent 
of plants 
rusted. 
1 
Untreated. 
80 
2 
Bordeaux mixture. 
90 
3 
Untreated. 
90 
4 
Ammoniacal solution. 
95 
5 
Untreated. 
70 
6 
Potassium sulphide. 
75 
7 
Untreated. 
90 
8 
Bordeaux mixture. 
10 
9 
Untreated. 
70 
10 
Ammoniacal solution. 
75 
11 
Untreated. 
90 
12 
Potassium sulphide. 
40 
13 
Untreated . .. 
100 
14 
Bordeaux mixture.. .. 
95 
15 
Untreated. 
75 
75 
16 
Ammoniacal solution. 
17 
Untreated. 
100 
18 
Potassium sulphide. 
75 
19 
Untreated. 
90 
According to the foregoing estimate, the plats sprayed with Bordeaux 
mixture were much more free from rust than any of the others and 
potassium sulphide was better than ammoniacal solution. The early 
plowing did not seem to affect the results at all, so far as rust was con¬ 
cerned. Mr. Swingle was directed to collect material from all the plats 
and forward it to Washington for examination. This was done, and the 
