52 
FLORIDA STATE HORTIGUTTURAL SOCIETY. 
nose,” blue stone under the trees would 
be beneficial. 
Prof. Rolfs—In connection with this 
subject I would like tO' say it is what 
some people call physiolog^ical disease. 
That does not express anything, but it 
is due to malnutrition. It is very closely 
related to dieback. You can cure a tree 
by spraying it with Bordeaux mixture. 
Melanose and dieback do' not usually oc¬ 
cur on the same tree, although I have 
seen the two diseases on one tree. It is 
what you might call “citrus tree indiges¬ 
tion.” 
In the case of the dieback we made 
very careful experiments to see whether 
an application of blue stone to the soil 
would be of advantage. We found no 
advantage in treating the dieback in this 
manner. We also applied it to the leaves 
and found it of no advantage. We tried 
the lime on the leaves of the dieback tree 
and saw nO' advantage. In these experi¬ 
ments we had untreated plots that we 
used as checks. In three plots that were 
treated with Bordeaux mixture they at 
once responded and showed beneficial re¬ 
sults. Now, I will say that, not having 
made the experiment of applying blue 
stone to the soil, we are a little inclined 
to doubt if it would be advantageous in 
treating this disease. 
Mr. Waite—'In one section of our grove 
last year we had a good deal of fruit af¬ 
fected by melanose, and a gentleman liv¬ 
ing up the river who had quite a large 
grove, told me it was so badly infested 
that nearly all the fruit dropped ofif be¬ 
fore it was matured, and he said he used 
about one or twO’ pounds of blue stone 
around the trees, and the next year very 
little fruit was affected, and the second 
year there was none at all. I applied 
some, but did not know whether it was 
the right thing to do or not. 
Mr. Hoard—I have used blue stone 
as a remedy for dieback for several years, 
and always with good results. Have cur¬ 
ed small trees that were almost dead and 
put them, in fine condition. Have also 
used it on large seedling trees which were 
so badly affected with dieback that nearly 
all of the fruit would split and drop off 
early in the fall. I commenced using it 
on these large trees the year before last, 
with the result that the fruit was much 
improved last year; sO' I gave them an¬ 
other dose last year and am using it again 
this year. In using it on small trees, 
care must be taken not to use toO' much, 
as an overdose would be fatal. Large 
seedling trees will stand from three to 
five pounds twice a year, broadcast. 
, Member—What else do you do besides 
that ? 
Mr. Hoard—Nothing at all. When¬ 
ever I see a tree with symptoms of die¬ 
back I get some pulverized blue stone and 
apply it just as I would fertilizer. I have 
used it in the liquid form and have also 
put small pieces under the bark, but have 
come to the conclusion that it makes very 
little difference how it is. applied so the 
tree gets it, and have adopted the easier 
method of throwing it broadcast. 
Mr. Penny—I use blue stone under the 
trees. I put it on the crown roots and 
cover it over. I have thought possibly 
that is where they get the most benefit 
from the Bordeaux. 
Prof. Rolfs—Where we applied it to 
the soil there was no benefit from the 
Bordeaux. 
Mr. Donovan—I tried the same ex¬ 
periment last summer with blue stone in 
spreading in a circle around the tree to 
