CITRUS MELANOSE AND ITS CONTROL 49 
until May 15. But the greater the delay the greater the danger of 
being caught unprotected, and it is certainly wise to get the work 
done promptly in the first part of what seems to be the best period, 
which would mean between April 25 and May 5. 
TESTS OF SUMMER AND FALL SPRAYING FOR MELANOSE CONTROL 
In 1920 spraying experiments were conducted during September, 
October, and November with Bordeaux-oil emulsion on seedling 
orange trees. The same material was used from June to November 
of 1921. In 1922 and again in 1923 similar spraying experiments 
were conducted during the summer months only. This summer and 
fall spraying was done too late to prevent or even reduce melanose 
infection On fruit then on the trees, and it also failed to check mela- 
nose the following year. From these rather extensive spraying ex- 
periments it is evident that spraying in the summer and fall can not 
be expected to reduce melanose outbreaks the following year. 
COMMERCIAL SPRAYING 
Commercial spraying in 1920. — Prior to 1920 no commercial spray- 
ing was done in Florida for melanose control, but that year several 
growers sprayed their groves for the prevention of this blemish. 
The dates of applications and spray materials were suggested by this 
office. For the most part 3-3-50 Bordeaux plus 1 per cent oil as 
emulsion was used. Among the several groves sprayed that year 
for the control of the disease was a large property in Marion County, 
another in Polk County, and a third in Pinellas County. In all of 
the groves melanose had been a major factor for many years, as 
there was an abundance of deadwood in them. Parts of these groves 
were sprayed from one to four times, the first application being made 
in late April. 
Although actual counts were not made in any of these groves to 
determine the exact control, close observation led the writers to be- 
lieve that in general the melanose control was very satisfactory in 
these three properties, about as good as in the groves sprayed experi- 
mentally at Winter Park and Orlando; but injurious effects devel- 
oped in the form of excessive scale 'infestation owing to the omission 
of insecticides during the summer months. 
Commercial spraying in 1921. — By 1921 the results of the success- 
ful spraying experiments and commercial tests carried on in 1920 
whereby melanose was successfully controlled in several parts of 
Florida by a single application of Bordeaux-oil emulsion had be- 
come generally known. Perhaps 20 or more groves were sprayed 
in 1921 at such times as to have the job completed by about May 1. 
In every instance the disease was reduced markedly and in most cases 
the control was almost perfect. On an average fully 90 per cent of 
the sprayed fruit matured commercially free of the disease. Most 
of these groves were sprayed in summer for scale control, but those 
few which were not so sprayed thoroughly with oil emulsion had a 
heavy scale infection by fall. 
Commercial spraying in 1922. — By 1922 growers generally had be- 
come much interested in spraying for melanose because of the success 
of the preliminary spraying trials and because the market was show- 
24975°— 27 4 
