CITRUS MELANOSE AND ITS CONTROL 
47 
The crop of Phomopsis spores was unusually large in March and 
April, and everything pointed to a heavy fruit infection with the 
onset of the rains. This was particularly true in the grove where the 
experimental spraying was being conducted. 
The spray materials used, dates and numbers of applications, to- 
gether with the results obtained from this experimental spraying 
for melanose control in 1924 are given in Table 11. 
Again, it is shown that a single application of Bordeaux-oil emul- 
sion applied before the period of heavy melanose infection gives 
a good commercial control of the disease. Bordeaux-oil emulsion 
applied March IT, even before many blooms opened, had a marked 
effect upon melanose infections. Progressively later applications 
up to the onset of long rainy periods increasingly gave better results, 
but wherever the sprays were applied well after the June rains had 
set in the control was not satisfactory. 
Two and three applications of Bordeaux-oil emulsion gave some- 
what better results than single applications, but the difference was 
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Fig. 11. — Rainfall (in inches) at Orlando, Fla., during March, April, May, and 
June, 1924 
not sufficiently great to warrant the expense of more than a single 
application properly timed. 
Neutral copper acetate and the sulphur compounds are not nearly 
so effective against melanose as standard Bordeaux-oil emulsion. 
Rainfall during the spring months of 192^. — The weather in the 
neighborhood of Orlando in the spring of 1924 was very unusual. 
Because of the cold, wet spring, growth was slow in getting started, 
and the blooming period hung on much later than normal. A 
heavy melanose infection on leaves occurred during March, but 
because of the delayed bloom there was very little fruit then exposed 
to infection. April was fairly dry and May likewise was not espe- 
cially wet. 
Slight fruit infection developed in late April and early May, and 
somewhat more occurred during the latter part of that month, but 
it was not until June that heavy fruit infection occurred — a month 
later than usual. 
The rainfall at Orlando, Fla., during the spring months of 1924 
is shown in Figure 11. 
