The Palatka news and advertiser. [volume] (Palatka, Fla.) 1908-19??, 1910-09-09
the MELANOSE
ON CITRUS TREES
New Disease Spreading i
Crescent City Groves.

view disease OpredOinS III
Crescent City Groves.
Agricultural Experiment Station Now
Investigating.
On invitation of Mr.. B. F. Tillingh-
hast of this place, Professors B. F.
Floyd and H. S. Fawcctt of the depart
ment of Plant Pathology at the Agricul-
tural Experiment Station connected with
the State University at Gainesville, visit
ed Crescent City last week for the pur-
pose of investigating new disease--or
at least one that has become so prevalent
as TO become oticeable-which grow
ers in this vicinity have detected lately
in their groves.
AS soon as these gentlemen were
shown the affected trees they pronounced
it MELANOSE.
Under the guidance of Mr.. r. |.
Boardman, Mr.. Tillinghast and Col.
Graham, Professors Floyd and Fawcett
visited the groves of f. II. Williams, D.
Varnes Mccormick & Hubbs, B. f.
Tillinghast, COL, Graham, L. A. Hurl-
but, David Dawes, w. f. Glynn and A.
P. DeWolf. The disease was found in
all these groves TO limited, extent, but
in the Hurlbut grove much more was
found than in any of the others.
Prof. Floyd went through the groves
to the south of town and marked with
copper tags some 20 different specimens
of fruit-part of which was affected
with the disease and part not He ex-
poets TO return in about month and re-
examine the fruit on the marked trees
for the purpose if possible of determin-
ing the cause of its spread.
Both these gentlemen will return to
Crescent City about October list, at
which time they will be glad TO meet as
many OF the growers as care to see them.
If possible due notice of their coming
will be given in the News.
Prof. Faucet visited the groves TO the
north and got samples of the wood,
roots and soil. What is known of this
disease appeared IN an article by Prof.
Floyd in a late issue of the Florida
Fruit and Produce News, which we re.
produce as follows:
NdEJ ANNSE
There has been much complaint dur
ing the present summer of the presence
of Melanose on citrus fruits. The most
of these complaints have come from the
northern half of the citrus belt, where
the disease seems TO be the most preva-
lent. One grower writes, There are
thousands of oranges in the groves herea-
bouts affected" The question of all is,
What is it and what is the treatment
General Appearance.
Melanose is a disease that starts only
on the young leaves, stems and fruit.
As the tissue of these parts grows older,
ii becomes immune to attack. The in
dividual marks, or spots, caused by the
disease, start as Sunken points, which
grow larger and more evident as the it's
sue grows older. They may reach a
diameter as great as 1-16 of an inch.
Frequently these marks are so plentiful
that as they grow they run together,
forming a mass or area in which the in
dividuality of the marks will be lost
The individual markings, and some
times the areas, become arranged in cir
Giles, or parts of circle. This is char
acteriStic of MelanoSe.
In many cases, particularly il the fruit
hangs so that wafer drips onto it from
leaf or branch above, the location of
the areas will resemble withertip tear
staining.
Description of the Marks.
The markings of the MelanoSe in its
mature condition are wax-like and red
dish brown in color. They somewhat
resemble drop of melted sugar burned
TO a reddish brown color They are
slightly raised above the surrounding
surface.
Effect Upon the Plant.
Leaves, stems and fruit are affected by
the Melanose. Where markings are
very plentiful the leaf may be stunted
and deformed. Such leaves will be
more or less bleached.
Upon the stems and fruits the mark
ings more frequently run together, form
ing areas. Where the disease is severe
the stems will be more or less complete
lv covered with the markings. Young
terminal twigS, when severely affected,
will die and dry up, appearing very
much the same as the stained terminal
branches in dieback.
The fruit, when severely affected at
an early age, will be Stunted. In most
cases it will grow to normal size, but
will have the markings more or less
completely scattered over its surface.
The markings are not attached bodies
like scale, but are part OF the tissue
of the fruit itself. Therefore they can
not be removed and the fruit is worth
less for shipment.
The development of areas is greatest
on the fruit Very often they are large,
cake-Iike, and cracked in lines like
dried mud.
MeIanose and Dieback.
1t frequently happens that MelanoSe
and Dieback are confused. In some
cases II requires very ClOoC OpSSi NatIoh
10 distinguish between the two. The
following are some of the points of diff
ference between the two diseases.
Melanose.
I. The markings of the Melanose on
the leaves, stems and fruits are the same:
2. It's markings are very superficial
and in most cases they are slightly
raised above the surrounding tissue.
8. The markings are very small, in
dividuaI, and scattered like pepper over
the affected surface. Often areas of the
markings will interlaCe, surrounding
little fields of green.
1. The markings are sometimes ar
ranged in circles or parts OF circles.
5. No gum is formed in the angles
of the segments and surrounding the
seed in the fruit.
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