CITRUS MELANOSE AND ITS CONTROL 
39 
consecutive days. No appreciable melanose infection had taken place 
when the first application was made ; however, considerable infection 
had developed by the time the second application was made, and 
probably all of the infection had taken place when the third applica- 
tion was put on. 
> Table 8. — Spraying experiments for melanose control with various materials on 
orange and grapefruit trees at Orlando, Fla„ in 1921 
Plot 
No. 
Materials used 
Num- 
ber of 
appli- 
cations 
Proportions 
Dates applied 
Per- 
centage 
of 
mela- 
nose 
infec- 
tions 
Degree of infection 
Lime - sulphur solu- 
tion. 
....do. 
...do. 
....do 
....do 
Dry lime-sulphur. 
....do 
—do 
Barium tetrasulphide. 
—do 
....do.... 
Commercial self- 
boiled lime sulphur. 
do 
do.... 
—do 
.-.do 
Copper soap. 
— .do 
.—do 
—do 
_-.do 
Bordeaux oil. 
do 
do 
...do.... 
...do.... 
...do.... 
do. 
do.... 
.do. 
.do. 
Commercial Bor- 
deaux powder. 
—do 
....do 
1-40. 
Apr. 28. 
do 
do. 
do — 
do 
4.4-40 
do 
do 
do 
do 
6.4-40 
do 
do 
do. 
do 
4.5-40 
do 
do 
do 
do 
M-O-3-50 
do 
do 
do 
do 
3-3-50+1 per 
cent oil. 
do 
do 
do 
do 
1-1-50+1 per 
cent oil. 
—do—,.-. 
do 
do 
do 
3-3-50+1 per 
cent oil. 
do 
do 
Apr. 28, May 23... 
Apr. 28, May 17, 
June 7. 
May 17 
June 7 . 
Apr. 28 
Apr. 28, May 24... 
Apr. 28, May 17, 
June 7. 
May 28.. 
June 7 
Apr. 28 
Apr. 28, May 24.. 
Apr. 28, May 17, 
June 7. 
May 28 
June 7-8 
Apr. 29 
Apr. 29, May 24.. 
Apr. 29, May 17, 
June 8. 
May 28 
June 8 
Apr. 29 
Apr. 29, May 20- 
Apr. 29, May 18, 
June 8-9. 
May 20 
June 8 
Apr. 29 
Apr. 29, May 30- 
Apr. 29, May 19, 
June 9. 
May 19 
June 9 
Apr. 30 
Apr. 30, Mav 23. _ 
Apr. 30, May 19, 
June 9. 
May 23- 
June 9 
May 23 
May 23, June 8. 
June8 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
Very severe on all 
grape-fruit trees 
and on larger 
orange trees. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Slight. 
Do. 
Do. 
Medium. 
Severe. 
Very slight. 
Do. 
Medium. 
Severe. 
Slight. 
Medium. 
Do. 
Very severe. 
Do. 
Do. 
Do.-/ 
Do. - ' 
{'iff .lw 
Tests for copper on sprayed leaves. — In order to determine the 
persistence of Bordeaux mixture spray residue, quantitative tests for 
the presence _of copper were made from leaves . sprayed .with r two 
strengths 
per cent oil 
suits are shown in Figure 
nee oi copper were made irom leaves . sprayed .witn two 
of Bordeaux mixture plus oil emulsMn 1 , 1 'M£~< : 15+*P&(9 r pttits 1 
[>il as compared with 1-1-50 plus 1 ^W^fWpf^a^J^- 
shown in Figure 7. " °* lm I 
