7io 
Journal of Agricultural Research 
Vol. XXIII, No. 9 
the much more efficient, with the advantage, between the two, in favor 
of the lime and sulphur dust. However, a burning and consequent 
serious injury to the plants was very evident with both sulphur com¬ 
pounds. This injury was sufficient to put these preparations out of 
consideration as practical remedies. The|Bordeaux dust, contrary to 
what might have been expected from thejcomparisons of relative per¬ 
sistence, was more efficient than the spray. No injury whatever resulted 
to the plants from the applications of the copper compounds. 
'-Y- A --V 1 1 ---“ —* A '--- 
JULY /?(/&. tSEET 
Fig. 5.—Diagram showing the daily precipitation record at Orlando, Fla., over the period covered by the 
spraying experiment, July 27 to September 13. 1919. 
Table II .—Results of applications of fungicides and persistence of copper applications 
Week 
ending— 
Bordeaux 
dust 
time sulphur 
dust 
Bordeaux spray 
4-4-50. 
Lime sulphur 
spray 1-40. 
Twice. 
Once. 
Control. 
j Twice. 
Once. 
Control. 
1 
Twice. 
| Once. 
Control. 
Twice. 
Once. 
Control. : 
1 
[Total spikes. 
287 
222 
208 
184 
284 
272 
20Z 
167 
110 
145 
116 
46 
Moldy spikes... 
67 
70 
61 
60 
55 
68 
71 
43 
37 
27 
17 
14 
Percentage moldy. 
*3-3 
3t*5 
29.3 
32.6 
19-4 
25 
35*3 
35* 7 
33*6 
18.6 
14. 7 
30.4 
g. 2 
Copper (mgm. per 100 gm. 
spikes). 
5 
0 
A, 2 
4* 65 
Percentage persistence. 
10 
•f* 
l6.8 
18.6 
Total spikes. 
300 
2 25 
206 
247 
310 
262 
225 
233 
171 
99 
197 
82 
Moldy spikes... 
14 
22 
16 
5 
8 
19 
13 
26 
19 
5 
14 
13 
1 « 
Percentage moldy. 
4- 7 
9*8 
7.8 
2 
2. 6 
7*3 
5*8 
XX. 2 
11.1 
5 
7*i 
158 
9 
Copper (mgm. per 100 gm. 
spikes). 
7.8 
(*) 
<*) 
IO. 45 
0 
Percentage persistence.. .. 
is. a 
(*) 
41.8 
0 
Total spikes. 
*r 
433 
285 
311 
314 
474 
450 
402 
371 
235 
296 
253 
112 
Moldy spikes. 
59 
57 
129 
19 
124 
134 
107 
125 
83 
47 
80 
40 
16 
Percentage moldy. 
136 
20 
4i*5 
6.1 
26. 2 
29.8 
26. 6 
33*7 
35* 1 
15*9 
31. 6 
35*7 
Copper (mgm. per 100 gm. 
spikes). 
6. 9 
0 
< 4 ) 
8.3 
33.3 
8.3 
Percentage persistence. .. 
13. 8 
0 
33* 3 
[Total spikes. 
476 
335 
268 
484 
324 
366 
387 
339 
194 
277 
124 
100 
Moldy spikes. 
26 
5® 
47 
6 
23 
65 
21 
48 
41 
4 
10 
22 
Percentage moldy. 
5-5 
14.9 
17*5 
x. 2 
7* x 
17.8 
5*4 
14 2 
21. 1 
1.4 
8.1 
22 
23 
Copper (mgm. per 100 gm. 
spikes). 
33.3 
4* 3 
16. 7 
4. 65 
( 5 ) 
(*) 
Percentage persistence .. 
66. 7 
8. 6 
66. 7 
18.6 
[Total spikes. 
473 
330 
278 
522 
475 
366 
319 
240 
193 
320 
243 
9i 
Moldy spikes.. 
17 
36 
34 
3 
7 
S 1 
7i 
6$ 
36 
14 
15 
26 
Percentage moldy.. .'t. 
3-6 
10.9 
12. 2 
.6 
i*3 
13*9 
22.3 
27. i 
18. 7 
4*4 
6.2 
28.6 
3° 
Copper (mgm. per 100 gm. 
spikes)... 
10.4 
4* 3 
17.9 
4* 3 
( 4 ) 
( 4 > 
Percentage persistence . 
20.8 
8.6 
71.6 
17. 2 
[Total spikes. 
528 
35i 
309 
399 
535 
447 
488 
344 
201 
3X9 
263 
100 
Moldy spikes. 
126 
149 
157 
22 
150 
229 
151 
i8x 
113 
30 
7i 
57 
Sept. 6 
Percentage moldy. 
33-9 
42*5 
50. 8 
5*5 
28 
51.2 
30.9 
52.6 
56- 2 
9.4 
27 
57 
Copper (mgm. per 100 gm. 
spikes) . 
33* 3 
(*) 
29.5 
4* 3 
( 4 ) 
( 4 ) 
Percentage persistence 
66. 7 
(*) 
xx8 
17. 2 
[Total spikes. 
484 
335 
285 
645 
571 
403 
427 
309 
121 
295 
222 
60 
13 
Moldy spikes. 
14 
24 
52 
5 
38 
4» 
34 
32 
12 
2 
4 
9 
Percentage moldy. 
2.9 
7.2 
18.1 
.8 
6-7 
12 
8 
11.8 
IO 
* 7 
1.8 
1*5 
1 The spraying was postponed until Monday on account of rain; dusts applied as usual. 
* Trace. * Burning evident. 4 Burned- 6 Much burning. 
