44 BULLETIN 1474, U. S. DEPARTMENT OF AGRICULTURE 
Table 10. — Results of spraying experiments for melanose control with various 
materials on orange and grapefruit trees at Orlando, Fla., in 1923 
Materials used 
Num- 
ber of 
applica- 
tions 
Proportions 
Date applied 
Melanose infection 
•G 
*$ 1 
fl 
a 
co 
3 
© 
>> 
s: 
.a 
< 
> 
to 
53 
3 
i 
Per Per 
Per 
Per 
cent cent 
cent 
cent 
2 
37 
23 
28 
54 
44 
2 

64 
32 
4 

50 
42 
6 
1 
65 
29 
6 

40 
50 
9 
1 
3 
64 
32 
1 

30 
44 
20 

51 
41 
7 

40 
29 
24 
35 
59 
5 
1 
34 
63 
3 

56 
33 
10 
1 
53 
43 
4 

41 
54 
5 

6 
28 
32 
22 
14 
58 
24 
3 
23 
44 
22 
10 
65 
35 


81 
18 
1 

41 
26 
32 
1 
25 
49 
23 
3 
60 37 
3 

64 1 33 
3 

67 
33 


79 
21 


67 
32 
1 

12 
41 
33 
13 
47 
43 
8 
1 
52 
35 
10 
3 
12 
64 
20 
3 
33 
48 
15 
3 
47 
44 
9 

3 
33 
36 
24 

36 
40 
18 
10 
36 
32 
19 

1 1 26 
25 
Bordeaux-oil emulsion. _ 
Do 
Do 
Improperly prepared 
Bordeaux mixture. 
'Neutral" Bordeaux 
mixture. 
Commercial Bordeaux 
paste, 1 
Commercial Bordeaux- 
oil emulsion. 2 
Do. 3 
Do 
Arnmoniacal solution of 
copper carbonate. 
Bordeaux-oil emulsion.. 
Do 
Do 
Do 
Do 
Do 
Lime-sulphur solution ._ 
Do 
Bordeaux-oil emulsion ._ 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Do 
Average of 12 check plots 
(no treatment) . 
3-4-50+1 per cent oil. 
do 
do 
do 
3-X-50+1 per cent oil. 
3-3-50+1 per cent oil. 
do 
2-2-50+34 per cent 
oil. 
3-3-50+1 per cent oil. 
5-3-50 
May 5, 15, June 5_. 
Apr. 24, May 7, 23. 
Apr. 5, 24, May 15. 
May 2 
.do. 
May 4. 
2-2-50+1 per cent oil. 
5-5-50+1 per cent oil. 
4-4-50+1 per cent oil. 
3-4-50+1 per cent 01L 
do 
do 
1-40. 
.do. 
3-4-50+1 per cent oil. 
...do 
...do 
...do.. 
...do 
...do 
...do 
...do 
...do -. 
...do 
...do _. 
—do 
...do 
...do 
...do 
...do 
...do 
...do - 
May 2 
do 
do 
Apr. 16, May 23..- 
Apr. 24, May 23— 
May 5, 23 
Apr. 25, May 7, 25. 
May 4, 25 
Apr. 25, May 15, 
June 6. 
Apr. 25, May 15 
Apr. 16, May 5 
Apr. 11, June 6 
Apr. 11, May 24.. ._ 
Apr. 11, May 15..- 
Apr.JLl, May 7 
Apr. 11, 25, May 15. 
Apr. 11, 25 
June 15 
June 6 
May 24 
May 15 
May 4 
Apr. 25 
Apr. 16 
Apr. 11 
Apr. 3 
Per Per 
cent cent 
1 
34 
A commercial Bordeaux paste to which oil emulsion was added in the spray tank. 
A ready-mixed commercial Bordeaux-oil emulsion, type A. 
A ready-mixed commercial Bordeaux-oil emulsion, type B. 
It is evident that the control was not as perfect as in former years. 
This is doubtless due to a slight but general infection that occurred 
in late March. 
The plots sprayed with a standard 3-3-50 Bordeaux plus 1 per cent 
oil as emulsion or its equivalent before the middle of April were not 
as well protected as those sprayed just before the May rains set in, 
while those sprayed for the first time well after the rains set in were 
in general not so satisfactorily protected. From these tests there is 
again evidence that if a single spray application is made before the 
May rains set in, melanose infection will be largely eliminated: that 
the commercial Bordeaux mixtures plus oil gave satisfactory results ; 
