102 
FLORIDA STATE HORTICULTURAL SOCIETY. 
limb weakens, the ever-present wither- 
tip fungus comes in and kills it back very 
rapidly. 
(3). A third manifestation of the 
disease is seen on the fruit, on which 
there appear, usually in July or August, 
faint rings. These rings slowly become 
colored and sunken, while in many cases 
the interior of the ring remains green 
and apparently uninjured. The fruits so 
attacked color prematurely, and many 
of them drop before picking time. 
About a year ago I began experiments 
on a grove near Bayview on about 175 
trees, with the view of getting some def¬ 
inite information that might lead to a 
remedy. It is too soon to report def¬ 
initely on these experiments, as they 
must be continued another year before 
any conclusions can be drawn; but I 
might say that experiments with Bor¬ 
deaux mixture were made every two 
months through the year, in addition to 
other experiments of a different nature. 
I found that the spraying diminished 
the amount of spotting on the fruit to 
some extent; but that where it was used 
every two months three times or more 
in all, the Purple Scale increased so rap¬ 
idly that it was a question whether these 
scale insects did not do more harm than 
the disease would have done if let alone. 
Considerable progress is being made in 
learning how the disease develops and 
spreads, and it is hoped that in time we 
shall have worked out a remedy for the 
trouble. Such scientific work is usually 
quite slow. As you know, the die-back 
of the orange was fifteen years under 
investigation before a practical way of 
controlling it was worked out. The Fed¬ 
eral Government has spent $30,000 to 
$40,000 in the investigation of the blight 
of citrus; and although considerable 
progress has been made in finding out 
the nature of this disease, no practical 
remedy has as yet been found. In most 
diseases it requires years for such investi¬ 
gations. In rare instances a remedy may 
be worked out in a short time. Profes¬ 
sor Rolfs worked out a remedy for the 
phytoptosis of potatoes in ten days, and 
this remedy has never been improved 
upon; but this is a rare case. It cannot 
be known in advance whether it will re¬ 
quire ten days or ten years to find a 
remedy for any given disease. 
Fig. 1. Scaly Bark disease on orange 
limb severely affected. 
Fig. 2. Orange showing rings and 
spots due to Scaly Bark disease. 
