Title: How to treat your palm with antibiotic
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Permanent Link: http://ufdc.ufl.edu/UF00076442/00001
 Material Information
Title: How to treat your palm with antibiotic
Physical Description: Book
Creator: McCoy, Randolph E.
Publisher: Agricultural Research Center, IFAS, University of Florida
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Bibliographic ID: UF00076442
Volume ID: VID00001
Source Institution: University of Florida
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Resource Identifier: oclc - 144513113

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( I-)

How To Treat Your Palm With Antibiotic

for control of

Lethal Yellowing of Coconut palm


Lethal Decline of Pritchardia palm

Research Report ARC-FL74-3

Agricultural Research Center, Fort Lauderdale

Institute of Food & Agricultural Sciences

University of Florida


fatal, highly epidemic disease
of coconut palm limited to land
areas within and bordering the
Caribbean Sea. The disease was
reported on the Florida mainland
in late 1971, killing 2,000
coconut palms within one year and
an estimated 20,000 trees within
two years.

The first symptoms to appear
in a lethal yellowing diseased
tree are premature nutfall and
the death and discoloration of
flower stalks, often before they
emerge from their buds. A palm
which drops a large number of
partially developed coconuts with'
dark discolorations at the stem
ends should be checked for discolored
flower stalks. This 's the most


diagnostic symptom of lethal
yellowing. These flower stalks
will be discolored dark brown from
the tips back, and may hang limply
as noted in Fig. la. The small
male flowers will adhere to such
diseased flower stalks as opposed
to creamy-white healthy flower stalks
in which the male flowers drop
after blooming. Healthy flower
stalks will dry out naturally with-
out drooping after the male flowers
have dropped (Fig. Ib). Two or
three discolored flower stalks may
appear before any leaf yellowing
develops. The yellowing usually
begins in the lower fronds and
extends upwards into the crown over
a period of one to four months.
Finally the crown topples from the
tree leaving a dead telephonepole-
like stump.

The causal agent of lethal
yellowing is believed to be a



Figure 1.

Coconut flower stalks: la) Diseased. Ib) Normal. a. female flower.
b. bud from which flower stalk emerges. c. dead drooping flower
stalk tips typical of lethal yellowing, d. normal drying out of
flower stalk tips after blooming. e. male flower.

mycoplasma-like organism which
lives within the food-conducting
veins of the coconut palm. A
mycoplasma is an extremely small
cellular microorganism requiring
an electron microscope to visualize.
Mycoplasmas generally are smaller
than bacteria and are sensitive
to certain types of antibiotics
such as oxytetracycline.

may be achieved through an
Integrated series of measures
which currently include 1) cutting
trees in advanced stages of disease
so that they cannot spread the
causal agent to nearby healthy
trees, 2) quarantine of affected
areas so that diseased palms are
not moved out to areas free of
disease, 3) replanting or under-
planting with the Malayan Dwarf
*variety of coconut palm which is
known to be resistant to lethal
yellowing, and 4) antibiotic treat-
ment either as a preventative or
a curative measure.


be used on healthy coconut palms
in neighborhoods where lethal
yellowing is known to be present.
If lethal yellowing is not present
in your immediate neighborhood,
preventative treatments are not
necessary and would be an unwar-
ranted expense. The first diseased
palms in an area may be treated
curatively, as explained later, and
the surrounding trees then treated
The amount of oxytetracycline
to use and the timing of treatments
are important in order to obtain
a high degree of protection for
healthy palms. One gram of actual
oxytetracycline (see table 1)
injected at 4-month intervals
has proved highly effective in
preventing lethal yellowing. Such

treatments can reduce the tree
to tree spread of disease by five
times. Although the oxytetracy-
cline will only remain about one
month in the treated palms, injec-
tions may be spaced at 4-month
intervals due to the long incubation
period of the disease. These
treatments at 4-month intervals
must be continued as long as
lethal yellowing remains a threat
to your tree.

What to expect: While
preventative treatments have
conclusively been proved to
reduce the rate of spread of
lethal yellowing, a small number
of treated palms will become
diseased. In such cases the trees
should receive curative treatments
as described below.

made on coconut palms already
showing symptoms of lethal
yellowing if the disease has not
advanced too far. Preferably,
trees should be treated before
any yellowing appears in the crown.
Trees with a small number of
yellowed fronds may be treated
with higher doses of oxytetracycline,
but the chances for disease remission
are much reduced. Trees having one-
fourth or more of their fronds

yellowed should be

cut and removed.

as they cannot be expected to respond
to treatment.

Pre-Yellowing Phase: Coconut
palms showing the symptoms of pre-
mature nutfall and/or flower stalk
discoloration as shown In figure
la with no more than one yellowed
frond should be Injected with one
to three grams of actual oxytetra-
Scycline (see table 1 for teaspoon
equivalents) dissolved in a minimum
of oz. of water per gram (up to
16 oz,water total may be used
depending on injection method).
These injections should be repeated
'at 4 month intervals.

Expected Results: In extensive
tests, 50% of all diseased coconut
palms treated prior to yellowing
developed no further symptoms of
disease and began producing healthy
new fronds and flower stalks within
3 months. Approximately 25% showed
little or no response and died.
The remainder exhibited varying
degrees of yellowing, but were
able to survive and produce
extensive new foliage. In effect,
then, the pre-yellowing curative
injection can be expected to save
about 75% of the trees receiving

These treatments must be
repeated at 4-month intervals to
keep a tree free of symptoms.
If a tree begins to yellow prior
to the 4-month interval, it is
suggested that an additional
.injection be given at that time.
It must be noted that a tree
which begins to yellow is physi-
cally weakened and its chances
for survival are diminished
similarly to a tree which has
been transplanted.

Early Yellowing Phase:
Diseased coconut palms having a
small number of their lower fronds
yellowed (six or less) may be
treated with oxytetracycline,
but have only about a 25 to 50%
chance of survival. Even so,
some people may want to treat
such trees. It Is recommended
that these trees receive 6 grams
actual oxytetracycline (see table
1) in 3 to 16 oz. water, depending
on the type of injection equip-
ment used.


PALM is a disease which has appeared
In Florida on Pritchardia thurstonil
and P. pacifica (Fiji Fan Palm)
palms growing In areas where lethal
yellowing is attacking coconut palm.

Mycoplasma-like bodies have been
seen in lethal decline affected
Pritchardia pacifica as well as In
lethal yellowing affected coconut.
The causal agents are believed to
be identical, although the evidence
is circumstantial.
Lethal decline of Pritchardla
palm can be recognized upon the
appearance of dark brown, dead
young flower stalks, as in coconut.
Yellowing begins in the lower
fronds and can kill an affected
palm In about 3 months. Early
in the development of this-disease
the folded bug or 'spear' leaf in
the center of the crown will die,
turn brown and collapse. Control
measures for lethal decline of
Pritchardia are similar to those
already mentioned for coconut,
except that.no resistant variety
is known and only curative anti-
biotic injections are approved.


No preventative testing has
been done for lethal decline of
Pritchardia palm and only curative
recommendations may be made for
Pritchardia thurstonl. Again,
as in coconut, the more advanced
the disease, the less are the
chances for survival. Pritchar-
dia palms exhibiting death of
young flower stalks and spear leaf
collapse may be injected with one
gram of actual okytetracycline
(see table 1) In 2 to 16 oz. water,
depending on the type of injection
equipment used. Chances for
remission are excellent, even
though yellowing may continue.
Treated Pritchardias have often
produced a whole new crown after
losing most of their old leaves
to disease.


It is recommended that the
antibiotic solution be Injected

directly Into the trunks of palms
to receive treatment. Spraying or
soil drenches will not work. For
injection, a hole must be drilled
2 or 4 inches into the trunk usually
at a slight downward incline. The
diameter of the hole will depend on
the type of equipment being used.
Of four methods suggested, two
are commercially available,
one may be easily rigged .by the
homeowner, and one is not
commercially available at this
time. Undoubtedly other injec-
tion methods will become available
in the future and the consumer
should judge each on its own

An antibiotic solution may be
introduced Into a tree through
a simple gravity feed mechanism
that the average homeowner may
assemble (Fig. 2). Materials
required are a one quart plastic
milk or bleach bottle, a cork,
a piece of plastic tubing, and
a 3 Inch piece of inch diameter
copper tubing. A Inch diameter
hole is drilled at a slight
downward angle 4 Inches into
the trunk about 4 to 5 ft. above
ground level and the copper
tubing hammered 1 inch deep
into the hole. The proper dose
of oxytetracycline is dissolved
in 8 to 16 oz. of water and
placed in the plastic container
which is then corked. A hole
is bored In the cork and the
plastic tube inserted. The
bottle is then inverted and
hung from the tree with the
plastic tubing connected to
the copper tube in the trunk
of the tree. A small ventilation
hole must be punched in the
container to allow air to enter.
The copper tube and plastic
tubing must be tapped gently
so that all air bubbles are
removed. The presence of air

Figure 2.

Gravity feed injec-
tion; a. copper
tubing, b. plastic
tubing, c. cork,
d. one qt. plastic
bottle, e. suspend
bottle from wire
threaded through
holes cut in bottle,
f. hole drilled
in tree trunk.

bubbles In the system will
present antibiotic uptake.
If no uptake occurs after
several hours,,tap the tubing
again to release air bubbles.
Sixteen ounces of solution
should be taken up overnight.
If no uptake occurs in 24
hours, discard the old
solution and try again at a
new site with fresh solution.
SGravity flow injection is
'simple, but is not as effi-
cient as the following methods.

Mauget injector is a small
disposable plastic container
that is commercially available.
It is filled with L oz. solution,
used once, and discarded. A
1/8 inch diameter hole is drilled
3 inches into the trunk, a feeder
tube inserted one inch deep
with a special tool, and the
filled plastic unit placed on
the tube (Fig. 3). The solu-
tion should be taken up after
4 hours to overnight. Doses
higher than one gram should be
placed in several units, with
one gram of actual antibiotic
in each unit in 1/2 oz. water.
The Mauget injector has proved
highly efficient in introducing
oxytetracycline into coconut
tissues, as long as a hole is
drilled into the trunk prior to
inserting the feeder tube.

The Minute Tree Injector is a
commercially available device
that can be used for repeated
rapid injections of small
volumes of solution (Fig. 4).
Each gram of active oxytetra-
cycline should be dissolved in
2 to 1 oz. of water and placed
in the solution reservoir.


Figure 3.

Mauget Injector."
a. feeder tube
to insert in hole
drilled in trunk,
b. fluid reservoir,
c. cap.

Figure 4. Minute Tree Injector.
a. fluid reservoir,
b. pump handle,
c. needle to insert
in hole drilled in

Then a 5/32 inch hole is
drilled 3 to 4 inches into
the trunk, the needle inserted,
and the handle pumped. Approx-
imately one minute is required
to inject one oz. of solution.

Another method used extensively
in our research program is
air pressure injection; how-
ever, no equipment is commer-
cially available at this time.
This method is similar to the
gravity flow technique of
Fig. 2 except that a metal
tank capable of holding 100
p.s.i. air pressure is used
rather than a plastic bottle.
Sixteen oz, of antibiotic solu-
tion is placed in the tank
which is then filled with
compressed air to 100 p.s.i.
at a service station. All
fittings and hoses must be
suitable for high pressure.
Also, a 1/2 by 3 inch hollow
lag screw is used to connect
the hose to the tree trunk
rather than a simple copper'
tube. With this method 16-
oz. of solution may be injected
in approximately 30 minutes.

In summary, oxytetracycline
injections can help prevent
lethal yellowing symptoms from
appearing in coconut palm,
and are about 75% effective
in producing disease remission
in diseased coconuts treated
prior to yellowing. Chances
b for recovery lessen as the
disease becomes more advanced.
Oxytetracycline is also
effective in remitting lethal
decline symptoms in the
Pritchardia palm. Remember
that not all trees will respond
to treatment, that it will
take about 3 months from the
time of treatment until a
diseased tree will begin to
produce new growth, and that
trees should be retreated at
4 month intervals. Do not
cut a tree that begins to
yellow after treatment, even
if the spear leaf collapses
as the tree still has a 50%
chance of survival. Hope-



fully through the integrated
use of the control methods
of quarantine, cutting trees
with advanced cases, replanting
with resistant varieties, and

antibiotic therapy, Florida
will be able to live with
these palm diseases and still
maintain the tropical appear-
ance lent by these palms.

Table 1. Grams actual oxytetracycline per volume measure of
Terramycin Tree Injection Formula (R) and minimum
amount of water to dissolve antibiotic. More water,
up to 16 oz. total, may be used, depending on
Injection methods.

Grams Volume measure of Terramycin Amount of
actual oxytetracycline Tree Injection Formula powder water to use

one slightly rounded teaspoon

one level Tablespoon

two level Tablespoons

I oz

1 1 oz

3 oz

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