Citation
Exotic woody plant control

Material Information

Title:
Exotic woody plant control
Series Title:
Circular
Creator:
Langeland, Kenneth A
Exotic Pest Plant Council -- Publications Committee
Place of Publication:
Gainesville
Publisher:
Florida Cooperative Extension Service
Publication Date:
Language:
English
Physical Description:
16 p. : ill. (some col.) ; 28 cm.

Subjects

Subjects / Keywords:
Woody plants -- Integrated control -- Florida ( lcsh )
Woody plants -- Control -- Florida ( lcsh )
Plant introduction -- Florida ( lcsh )
South Florida ( local )
Herbicides ( jstor )
Wildlife damage management ( jstor )
Vegetation ( jstor )
Genre:
government publication (state, provincial, terriorial, dependent) ( marcgt )

Notes

General Note:
Cover title.
General Note:
"Prepared by Exotic Pest Plant Council, Publications Committee"--Verso cover.
Funding:
Circular (Florida Cooperative Extension Service) ;
Statement of Responsibility:
Ken Langeland, editor.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
22999356 ( OCLC )

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DOCUMENT


EXOTIC WOODY PLANT CONTROL


Ken Langeland, Editor

Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences
University of Florida / John T. Woeste, Dean


Circular 868







TABLE OF CONTENTS

Introduction ...........................................................................................................1

Types of Control Methods ................................................... .............................

Prevention .............................................................. ............................... 1
Biological Control..................................................................... ............. 1
M annual Rem oval.................................................................................. 2

Mechanical Removal ............................................................................. 2

Physical C ontrol........................................................................................... 2
H erbicides .................................................................................................... 3
Australian pine (Casuarina spp.)..................................................................... 8
Brazilian pepper (Schinus terebinthifolius Raddi) ............................................. 10

Asiatic colubrina (Colubrina asiatica (L.) Brongn.) ............................................ 12

Melaleuca (Melaleuca quinquenervia (Cav.) Blake) ............................................. 14







Prepared By
Exotic Pest Plant Council
Publications Committee


Committee Members: K A. Langeland, Editor M. P. McMahon
L. D. Whitaker, Chairman J. B. Miller
R. J. Burkhead D. C. Schmitz
J. M. Kleen R. H. Skinner
W. N. Kline C. E. Timmer
M. D. Maffei J. G. Duquesnel


Cover photo by Diane Johnston, University of Florida, AREC, Ft. Lauderdale, Florida
Illustrations by Laura Reep, courtesy of the Center for Aquatic Plants, IFAS, University of Florida
Mention of a trade name or a proprietary product does not constitute a guarantee or warranty of the product by the
University of Florida or the Exotic Pest Plant Council and does not imply its approval to the exclusion of other
products that may also be suitable. Any product trade names that are listed are for the benefit of the reader and the
list may not contain all products available. Always read carefully and follow all herbicide label directions. It is
unlawful to use a pesticide in a manner that is inconsistent with or not specified on the label.








INTRODUCTION


Extensive urbanization in Florida has led to the
introduction of a great number of exotic (nonnative)
plants in landscapes. Florida's mild climate and ample
rainfall for many months of the year provide a suitable
habitat for many of these introduced plants to escape
from cultivation and become naturalized. It has been
estimated that 27% of Florida's 3448 named plants
(excluding ornamental plantings) are exotic and this
suggests that Florida's natural vegetation is becoming
displaced (Daniel B. Ward, personal communication).
Some of these introduced plants become aggressive
invaders of native plant communities because their
population is no longer kept in check by factors such as
competing species and predators that have coevolved
with them.
Large areas of southern and central Florida have
been severely altered (probably beyond our present
restoration ability) by urbanization and other activities
of man. However, certain areas, such as state and
national parks, have been relatively protected and
attempts are being made, by the National Park Service,
Florida Department of Natural Resources and other
agencies, to preserve (or restore) the ecology of these
areas in as pristine a condition as possible. This en-
deavor includes management, or elimination where
possible, of introduced vegetation. Several very aggres-
sive introduced plants have already replaced native


Florida plant communities in some areas and, thereby,
drastically changed the landscape both visually and
ecologically. These include Australian pine (Casuarina
spp.), Brazilian pepper (Schinus terebinthifolius Raddi),
Asiatic colubrina (Colubrina asiatica (L.) Brongn.) and
melaleuca (Melaleuca quinquenervia (Cav.) Blake)
In recognition of the loss of natural communities
caused by these and other aggressive exotic plants, the
Exotic Pest Plant Council (EPPC) was formed to coordi-
nate efforts of various agencies into developing man-
agement programs and increasing public awareness.
This circular is an example of those efforts. It presents
current methods for control of Australian pine, Brazil-
ian pepper, Asiatic colubrina and melaleuca that have
been tested and compiled by members of the EPPC.
Management programs include the use of manual re-
moval, mechanical removal, physical controls and her-
bicides, alone or in combination. Biological controls are
currently under study and should be implemented in
the future. Characteristics of the different types of
control measures are discussed. All herbicide treat-
ments listed have been found effective under certain
circumstances. However, since choice ofherbicide appli-
cation will depend upon environmental conditions and
personal preference, they are not ranked in this publi-
cation.


TYPES OF CONTROL METHODS


Prevention
The importation and spread of noxious exotic vegeta-
tion can be significantly reduced by public education. It
is the responsibility of those who are aware of the
problems caused by noxious exotic plants to educate
others as to their identity and control to prevent further
ecological damage to native ecosystems.

Biological Control
Native plant communities evolve with a complex
relationship of natural controls that keep them in
balance. These natural controls may include environ-
mental restraints, competing species, herbivores (e.g.,
insects) and pathogens. When plants are introduced
into new areas, they often have a competitive advan-
tage over native plants because natural controls of the
introduced plants are not present. This competitive
advantage may allow introduced plants to cause prob-
lems, such as displacing natural plant communities.
Biological control is the purposeful introduction of
natural controls such as insects and pathogens, to help
provide balance among native and introduced plants.
The type of biological control proposed for exotic
woody vegetation in south Florida is called the classical
(or introduction) approach. Classical biological control
requires a large initial investment of time and money.


However, a successful program can have long-term
benefit to cost ratios of 100:1 and higher.
Classical biological control involves the following:
(1) Surveys are conducted to identify natural controls in
a plant's native habitat. (2) Natural controls that are
promising biocontrol agents are studied and quaran-
tined to determine their ability to suppress the host
(pest) and to insure that they are host-specific (cannot
significantly damage or reproduce on nontarget plants
such as native plants, ornamental plants or crops).
These studies are conducted where the organism is
collected and in the region where it is to be released. (3)
Biological control agents) are released in order to
establish self-perpetuating populations that will sup-
press growth of the pest. (4) If necessary, biological
control agents are collected from established popula-
tions and moved to new locations.
Classical biological control has been used success-
fully for many years. Probably the first effort was the
use of an insect (Dactylopius ceylonicus Green) to con-
trol prickly pear cactus (Opuntia vulgaris Mill.) in
southern India during the 1860s. More recently,
alligatorweed flea beetle (Agasicles hygrophila) and
alligatorweed stem boring moth (Vogtia malloi) have
successfully suppressed alligatorweed (Alternanthera
philoxeroides (Mart.) Griseb.)inthe southeastern United
States.








INTRODUCTION


Extensive urbanization in Florida has led to the
introduction of a great number of exotic (nonnative)
plants in landscapes. Florida's mild climate and ample
rainfall for many months of the year provide a suitable
habitat for many of these introduced plants to escape
from cultivation and become naturalized. It has been
estimated that 27% of Florida's 3448 named plants
(excluding ornamental plantings) are exotic and this
suggests that Florida's natural vegetation is becoming
displaced (Daniel B. Ward, personal communication).
Some of these introduced plants become aggressive
invaders of native plant communities because their
population is no longer kept in check by factors such as
competing species and predators that have coevolved
with them.
Large areas of southern and central Florida have
been severely altered (probably beyond our present
restoration ability) by urbanization and other activities
of man. However, certain areas, such as state and
national parks, have been relatively protected and
attempts are being made, by the National Park Service,
Florida Department of Natural Resources and other
agencies, to preserve (or restore) the ecology of these
areas in as pristine a condition as possible. This en-
deavor includes management, or elimination where
possible, of introduced vegetation. Several very aggres-
sive introduced plants have already replaced native


Florida plant communities in some areas and, thereby,
drastically changed the landscape both visually and
ecologically. These include Australian pine (Casuarina
spp.), Brazilian pepper (Schinus terebinthifolius Raddi),
Asiatic colubrina (Colubrina asiatica (L.) Brongn.) and
melaleuca (Melaleuca quinquenervia (Cav.) Blake)
In recognition of the loss of natural communities
caused by these and other aggressive exotic plants, the
Exotic Pest Plant Council (EPPC) was formed to coordi-
nate efforts of various agencies into developing man-
agement programs and increasing public awareness.
This circular is an example of those efforts. It presents
current methods for control of Australian pine, Brazil-
ian pepper, Asiatic colubrina and melaleuca that have
been tested and compiled by members of the EPPC.
Management programs include the use of manual re-
moval, mechanical removal, physical controls and her-
bicides, alone or in combination. Biological controls are
currently under study and should be implemented in
the future. Characteristics of the different types of
control measures are discussed. All herbicide treat-
ments listed have been found effective under certain
circumstances. However, since choice ofherbicide appli-
cation will depend upon environmental conditions and
personal preference, they are not ranked in this publi-
cation.


TYPES OF CONTROL METHODS


Prevention
The importation and spread of noxious exotic vegeta-
tion can be significantly reduced by public education. It
is the responsibility of those who are aware of the
problems caused by noxious exotic plants to educate
others as to their identity and control to prevent further
ecological damage to native ecosystems.

Biological Control
Native plant communities evolve with a complex
relationship of natural controls that keep them in
balance. These natural controls may include environ-
mental restraints, competing species, herbivores (e.g.,
insects) and pathogens. When plants are introduced
into new areas, they often have a competitive advan-
tage over native plants because natural controls of the
introduced plants are not present. This competitive
advantage may allow introduced plants to cause prob-
lems, such as displacing natural plant communities.
Biological control is the purposeful introduction of
natural controls such as insects and pathogens, to help
provide balance among native and introduced plants.
The type of biological control proposed for exotic
woody vegetation in south Florida is called the classical
(or introduction) approach. Classical biological control
requires a large initial investment of time and money.


However, a successful program can have long-term
benefit to cost ratios of 100:1 and higher.
Classical biological control involves the following:
(1) Surveys are conducted to identify natural controls in
a plant's native habitat. (2) Natural controls that are
promising biocontrol agents are studied and quaran-
tined to determine their ability to suppress the host
(pest) and to insure that they are host-specific (cannot
significantly damage or reproduce on nontarget plants
such as native plants, ornamental plants or crops).
These studies are conducted where the organism is
collected and in the region where it is to be released. (3)
Biological control agents) are released in order to
establish self-perpetuating populations that will sup-
press growth of the pest. (4) If necessary, biological
control agents are collected from established popula-
tions and moved to new locations.
Classical biological control has been used success-
fully for many years. Probably the first effort was the
use of an insect (Dactylopius ceylonicus Green) to con-
trol prickly pear cactus (Opuntia vulgaris Mill.) in
southern India during the 1860s. More recently,
alligatorweed flea beetle (Agasicles hygrophila) and
alligatorweed stem boring moth (Vogtia malloi) have
successfully suppressed alligatorweed (Alternanthera
philoxeroides (Mart.) Griseb.)inthe southeastern United
States.






Biological control agents have not yet been intro-
duced for control of Asiatic colubrina, Australian pine,
Brazilian pepper or melaleuca. However, a major effort
is currently underway to identify natural control of
melaleuca and Brazilian pepper. Over 200 insects that
feed on melaleuca have been found in Australia and
several ofthese offer promise for introduction into south
Florida as biological control agents. It is important that
these studies continue. Additional initiatives to identify
biological control agents for other major nuisance exotic
vegetation, which threaten Florida's natural areas, are
equally important.
Research, implementation and results of biological
control are very slow. It is not possible to predict how
long it will take to have effective biological control of
Asiatic colubrina, Australian pine, Brazilian pepper
and melaleuca, or how effective these will be. Therefore,
other control measures are currently important, and
will be necessary even after establishment of successful
biological control.

Manual Removal
Manual removal of Australian pine, Brazilian pep-
per and melaleuca is possible for seedlings and small
trees. Manual removal of Asiatic colubrina branches
from desirable vegetation will usually be necessary
before other control methods are used. When removing
seedlings and small trees manually every effort should
be made to remove the entire root system because a 1/4
inch section of root can resprout.
The "Kelly Device" can facilitate manual removal of
seedlings and small trees that are difficult to remove by
hand (Figure 1). The "Kelly Device" was developed by
Bob Kelly of the Sierra Club while he was working with
his volunteer group in Big Cypress National Preserve
on their melaleuca removal program. The device con-
sists of three pieces of 3/4 inch plywood attached to-
gether with wood screws. The main piece of wood is cut
into an elongated oval shape 21/2 3 feet long and about
1 foot wide. The other two pieces of wood are cut such
that they will form a 4- to 5-inch wide border along one
side (the front) and one end (the bottom) of the main
piece of wood. The second two pieces are attached to
opposite sides of the main piece of wood with wood
screws such that they extend beyond the edge of the
main piece approximately V/2 inch, thereby forming a
groove into which the stem of a sapling can be placed.
Oval handholds, about 2 x 5 inches, are cut along the
edges of the device; three in front, two in back, and one
on top. If desired, dimensions of the device can be scaled
up or down for use on larger or smaller plants.
The device is used by placing it next to a sapling,
holding the stem of the sapling into the groove formed
by the three pieces of plywood, and rocking the device
away from the sapling on the curved bottom of the
device using the oval handholds. This extracts the
sapling from the ground using the leverage created by
the device.
Manual removal is labor intensive, but it can be


Figure 1. The "Kelly Device" can facilitate manual removal of
seedlings and small trees that are difficult to remove by hand.

effective as a follow-up to other control measures,
especially if a volunteer or low cost labor force is
available.

Mechanical Removal
Mechanical removal involves the use of bulldozers,
or specialized logging equipment to remove woody
plants. This method is used when an area is to be
cleared for a new land-use. Mechanical removal is not
effective for control of Australian pine, Asiatic colu-
brina, Brazilian pepper, or melaleuca when used alone
because disturbance of the soil creates conditions for
regrowth from seeds and root fragments, and further
invasion by pioneering exotic plants. Therefore, intense
follow up with other control methods is essential. Me-
chanical removal is usually not appropriate in natural
areas because of disturbances to soils and nontarget
vegetation caused by the equipment used.

Physical Control
Woody vegetation can be stressed or sometimes
killed by environmental alterations such as water level
manipulation or fire. Constraints, such as the need to
maintain water levels in water conservation areas,
liability involved with burning, and effects on desired
vegetation, will often limit the usefulness of these
methods. However, research to determine how physical







stresses can be incorporated into management pro-
grams (e.g., timing ofherbicide applications with flood-
ing) is important.

Herbicides
Regulations
Herbicides are a commonly used method of manag-
ing exotic woody vegetation. Use of herbicides (and
other methods of vegetation control in some instances)
in certain areas such as public waters and wetlands are
regulated by state and local agencies. For questions
regarding permits to control vegetation in public waters
contact one of the following Department of Natural
Resources regional offices:


Tampa
Orlando
West Palm Beach


813/626-5143
407/423-0673
407/793-5666


For questions regarding vegetation control in wetlands
contact the Water Management District (WMD) in
which you are located as follows:


Southwest Florida WMD
St. Johns River WMD
South Florida WMD


904/796-7211
904/328-8321
407/686-8800


A basic knowledge ofherbicide technology and appli-
cation techniques is necessary for safe and effective use
ofherbicides. For this reason, state agencies and federal
agencies require personnel involved in herbicide appli-
cation to be certified by the Florida Department of
Agriculture and Consumer Services (FDACS). It is
strongly advised that any individual who practices
herbicide application be certified by FDACS. The Uni-
versity of Florida Institute of Food and Agricultural
Sciences provides training and testing for certification
ofpesticide applicators. For information regarding pes-
ticide applicator certification, contact the Cooperative
Extension Service in your county.

Herbicide Absorption Characteristics
Contact herbicides. Contact herbicides act quickly
and are generally lethal to all plant cells that they
contact. Because of this rapid action or other physiologi-
cal reasons they do not move extensively within the
plant and are effective only where they contact plants.
They are generally more effective on annual, herba-
ceous plants, and seedlings. Perennial, woody plants
can be defoliated by contact herbicides, but they quickly
resprout from unaffected plant parts.
Systemic herbicides. Systemic herbicides are ab-
sorbed into the living portion of the plant and move
within the plant. Different systemic herbicides are
absorbed to varying degrees by different plant parts.
Systemic herbicides that are absorbed by plant roots
are referred to as soil active herbicides and those that
are absorbed by leaves are referred to as foliar active
herbicides. Some soil active herbicides, tebuthiuron for


example, are absorbed only by plant roots. Other sys-
temic herbicides, such as glyphosate and triclopyr, are
predominantly or only active when applied to and
absorbed by the foliage. Others, such as imazapyr, are
absorbed by both roots and shoots. When applied cor-
rectly, systemic herbicides act slowly compared to con-
tact herbicides. This slow activity allows them to move
to their site of action within the plant (e.g., roots,
leaves). Systemic herbicides are more effective for
controlling mature woody plants than contact herbicides.

Herbicide Selectivity
Nonselective or broad spectrum herbicides.
Nonselective or broad spectrum herbicides are those
that kill all or most plants that they come in contact
with. Many herbicides, such as tebuthiuron, hexazinone,
glyphosate, and imazapyr that are effective for control-
ling woody plants are broad spectrum and care must be
taken to avoid damage to nontarget, desirable vegeta-
tion. However, broad spectrum herbicides can be used
for selective weed control if special application tech-
niques, such as frill or girdle treatments (described
later), are used. These techniques insure the herbicide
only contacts the target plants.
Selective herbicides. Selective herbicides are those
that control certain plants but not others. Triclopyr and
2,4-D are examples of selective herbicides that are most
effective for controlling broad leaf plants (dicotyledons)
while grasses and related plants (monocotyledons) are
relatively tolerant. Therefore, certain woody plants can
be controlled and a grass community preserved. Herbi-
cide selectivity can be affected by the rate of application
and growth stage of plants. Factors that affect suscep-
tibility of Australian pine, Brazilian pepper, Asiatic
colubrina and melaleuca and nontarget native plants
are currently under investigation.

Environmental Fate of Herbicides
After application, herbicides may break down to
nonbiologically active products, adsorb to soil, or move
away from the application site unchanged. Breakdown
and adsorption may occur at different rates depending
upon the herbicide's chemistry, soil characteristics, and
other environmental factors. Since some of the herbi-
cides that are used for woody plant control do not break
down quickly and may move in Florida soils, damage to
nontarget vegetation or contamination of groundwater
may occur if proper precautions are not used. To avoid
unwanted results, the herbicide applicator must be well
informed of the chemical properties of the herbicide to
be used and under what particular circumstances it
should be applied. Always consult the herbicide label for
environmental precautions.

Environmental Factors
Affecting Herbicide Application
Rainfall. Rainfall can wash foliar applied herbicide
off before it is adequately absorbed into the plant. This







is a particular problem when using slowly absorbed
systemic herbicides such as glyphosate. Heavy rainfall
following frill and girdle application of a concentrated
herbicide solution can wash the herbicide into the soil
and result in damage to nontarget vegetation. Soil
active herbicides applied to ditch banks can also be
affected if heavy rainfall washes the herbicide away
before it can leach into the root zone. Applying soil active
herbicides to moist soil (following rain) is preferable
because this promotes quick diffusion of the herbicide
into the soil.
Lack of rainfall can also affect herbicide efficacy
because drought-stressed plants are less likely to absorb
both foliar and soil applied herbicides. Certain herbi-
cide labels such as glyphosate have precautionary
statements to this effect. The applicatorshould be aware
of potential weather conditions and should schedule
applications accordingly.

Wind. Wind can affect herbicide applications in
several ways. Foliar herbicide application during exces-
sive wind may result in poor coverage to the target
vegetation and cause drift that results in damage to
nontarget vegetation. Wind can also indirectly affect
the ability of plant leaves to absorb herbicides and
therefore, resulting poor control. Windy conditions should
be avoided when making foliar herbicide applications.

Temperature. Low temperature may affect herbi-
cide efficacy indirectly by affecting plant growth. At less
than optimum temperature, plant growth slows down,
and this may decrease herbicide absorption and/or
activity.

Soil chemistry. Soil and herbicide interactions are
complex. These interactions influence the activity and
movement of soil-active herbicides. The most important
factor is the ability of different soils to chemically bind
herbicides. Soil-applied herbicides usually have label
recommendations for use on different types of soils. In
general, soils with more organic matter and/or clay
have greater capacities for binding herbicides than
coarse, sandy soils and require higher application rates.
Since Florida soils, where woody plants are a problem,
include highly organic muck, sand, and very thin soil
layers over limestone, a broad range of soil-applied
herbicide behavior can be expected.

Water chemistry. Water chemistry can be an im-
portant factor in the performance of tank-mixed herbi-
cide applications because some herbicides can be inac-
tivated by suspended particles, dissolved organic mate-
rials and water hardness. Always take the follow-
ing precautions when obtaining water for tank mixes:

* Use the cleanest water available. Avoid sediments.
* When mixing herbicides known to react with hard
water, use the softest water available. If possible, use
softened or distilled water; lake water is next best
choice; avoid using well water.


* Minimize the amount of time that herbicides remain
mixed in water.

Some additives have been suggested to alleviate the
hard water problem, but these are still under study and
results, to date, have been inconsistent.

Herbicide Formulations
A herbicide formulation usually consists of the her-
bicide active ingredient dissolved in a solvent (e.g., oil or
alcohol), or adsorbed to a solid such as clay. Liquid
formulations often include an adjuvant that facilitates
spreading, sticking, wetting, and other modifying char-
acteristics of the spray solution. These special ingredi-
ents usually improve the safe handling, measuring, and
application of the active ingredient.

Water soluble liquids (WSL or L). Water soluble
liquids have the herbicide (e.g., amines) dissolved in a
water soluble solvent such as an alcohol. Since they
form true solutions they do not require agitation. They
are usually not compatible with oil-based carriers.
Emulsifiable concentrate (EC). Emulsifiable con-
centrates contain a mixture of petroleum solvents and
emulsifiers that allow an insoluble or low solubility
herbicide to mix with water. ECs require little agita-
tion. They cause minimum equipment wear because
they are nonabrasive. ECs may also be mixed with oil-
based carriers for low volume applications (e.g., basal
bark).
Flowable (F). A flowable formulation consists of an
insoluble solid phase suspended in a liquid. The active
ingredients in flowables are insoluble in water and form
suspensions when mixed with water. Therefore, con-
stant tank agitation is important when usingflowables.
Flowables share the handling advantages of an EC.

Dry flowable (DF). Dry flowables are formulations
that are insoluble in water but are formulated in such
a way that they can be easily poured and measured. As
with flowables, tank agitation is important to keep
them in suspension. They are much easier to handle
than wettable powders but usually are more expensive.

Granule (G) and pellet (P). Granules and pellets range
from 1%-40% active ingredient. Granules are conve-
nient for spot treatments, are ready to use, reduce drift
hazards, and can be easily applied. The disadvantage of
granules are their, sometimes, high expense per pound
of active ingredient.

Wettable powder (WP). Another common dry formu-
lation is the wettable powder. WP formulations re-
semble a fine dust and generally contain greater than
50% active ingredient. When mixed with water, agita-
tion is required to keep the insoluble particles of a
wettable powder in suspension. The advantages of a
WP are the lower cost, ease of handling, and ease of
measuring. Some disadvantages of WPs are the abra-







sion of suspended particles on spray equipment and the
requirement for constant tank agitation.

The Herbicide Label
All herbicide containers must have attached to them
a label that provides instructions for storage and dis-
posal, use of the product, and precautions for the user
and the environment. The label is the law. Itis unlawful
to use a pesticide in a manner that is inconsistent with
or not specified on the label. It is unlawful to alter,
detach, or destroy the label. It is unlawful to transfer
herbicide to an improperly labeled container. Misuse of
a herbicide is not only a violation of federal and state
law, but also herbicides used contrary to label directions
may cause unwanted results such as damage to nontar-
get vegetation. Make sure to have all appropriate labels
at the application site including supplemental labels,
special local need labels and emergency use labels.
The herbicide label contains a great deal of informa-
tion about the product and should be read thoroughly
and carefully before each use. Before applying a herbi-
cide, read the label to determine the following:

* Can the weed be controlled with the product?
* Can the herbicide be used safely under particular
application conditions?
How much herbicide is needed?
Is the product labelled for the site, i.e., ditch banks
only, canal banks, wetlands, etc.?
What is the behavior of the herbicide on different
types of soils?
What is the toxicity of the herbicide to fish and
nontarget vegetation?
When should the herbicide be applied (time of year,
stage of plant growth, etc.)?
Is the herbicide classified restricted or general use?
What is the signal word (DANGER, WARNING,
CAUTION) and safety equipment that should be
worn during mixing and application?

Read labels often even if you use the herbicide rou-
tinely. You may have missed something or it may have
changed. Labels are updated often by industry.

Herbicide Application Methods
Basal bark applications. Basal bark applications
are made by applying herbicide directly to the bark
around the circumference of each stem/tree up to 15
inches above the ground (Figure 2). Hand-held equip-
ment or backpack sprayers are usually used. The her-
bicide is sometimes in a ready-to-use form, but is
usually diluted in some carrier, such as diesel fuel,
kerosene, or mineral oil.

Foliar applications. Foliar applications are usu-
ally made by diluting herbicide in water and applying
to the leaves with aerial or ground equipment (Figure
3). Dilution is usually about 20:1 for aerial applications
and 50-400:1 when making ground applications for


woody plant control. Adjuvants such as surfactants,
drift control agents or other spray modifiers are often
added to the spray mix. Ground equipment ranges from
hand-held sprayers for applications to small individual
plants to large high pressure vehicle or boat-mounted
sprayers for larger vegetation. Foliar applications can
either be directed, to minimize damage to nontarget
vegetation, or broadcast. Broadcast applications are
used where damage to nontarget vegetation is not a
concern or where a selective herbicide is used.

Frill or girdle (sometimes called hack-and-
squirt) applications. Cuts, into the cambium, are
made completely around the circumference of the tree
with no more than 3-inch intervals between cut edges.
Overlapping and continuous cuts (girdle) are, some-
times, used for difficult-to-control species and large
trees (Figure 4). Do not make multiple cuts directly
above or below each other because this will inhibit
movement of the herbicide. Incisions should be angled
downward to hold herbicide and must be deep enough
to penetrate the bark and cambium layer. Herbicide
(concentrated or diluted) is applied to each cut until the
exposed area is thoroughly wet. Frill or girdle treat-
ments are slow and labor intensive but sometimes
necessary in mixed communities to kill noxious vegeta-
tion and minimize impact to desirable vegetation. To
further minimize potential impact to desirable vegeta-
tion, cuts can be wrapped with masking tape to prevent
rainfall from washing herbicide to the soil.

Injection. Special equipment (available from agri-
cultural or forestry equipment suppliers) is used that
'delivers a measured amount of herbicide into the tree
trunk. Injections should surround the tree at intervals
of 2- 3 inches between edges. They may be made at any
convenient height, usually 2-4 feet aboveground.

Stump treatments. After cutting and removing
large trees or brush, herbicide (concentrated or diluted)
is sprayed or painted on to the exposed cambium layer
next to the bark around the entire circumference of the
stump (Figure 5). Do not allow more than 1 hour to
elapse between cutting and applying herbicide.

Soil applications. Granular and pellet herbicide
formulations can be applied by hand, hand-held spread-
ers, specially designed blowers, or aerially. Soil-applied,
liquid, flowable or wettable powder herbicide formula-
tions can be applied with the same type of application
equipment described for foliar applications or spot guns
that can accurately deliver a measured amount of
herbicide.

Marker dyes. Marker dyes are very useful for keep-
ing track of what vegetation has been treated when
making applications to large numbers of individual
trees or stumps. Dyes are also a useful indicator of the
applicator's efficiency oflimiting herbicide contact with
nontarget vegetation and personal contact.












Figure 2. Basal bark applications are made by ap-
plying herbicide directly to the bark around the cir-
cumference of each stem/tree up to 1 inch above the
ground. In this application, waterproof boots and eye
protection are being worn. Additional protective clothing
is often required or advised, especially when handling
herbicide concentrate.


Figure 3. Foliar applications are made by diluting
herbicide (usually in water) and applying to the leaves
with aerial or ground equipment. In this application,
waterproof boots and eye protection are being worn.
Additional protective clothing is often required or advised,
especially when handling herbicide concentrate.


pI


Figure 4. Girdle applications are sometimes used
for difficult-to-control species such as melaleuca and
large trees. To further minimize potential impact to
desirable vegetation, cuts can be wrapped with mask-
ing tape to prevent rainfall from washing herbicide to
the soil.


;. "


Figure 5. After cutting and removing large trees or
brush, herbicide is sprayed or painted on to the
exposed cambium layer, next to the bark around the
entire circumference of the stump.


C










Botanical Descriptions
and
Control Recommendations
for
Australian Pine
Brazilian Pepper
Asiatic Colubrina
and Melaleuca







Other Common Names: Ironwood,
beefwood, she oak, horsetail tree.

Native Country: Australia.

Habitat: Occurs throughout south
Florida (from Orlando, south) on
sandy shores, pinelands, and in the
Everglades, above the water table or
mean high water line. Frequently
colonizes disturbed sites, such as
filled wetlands, road shoulders,
cleared land, and vacant lots. Aus-
tralian pine is capable of colonizing
nutrient-poor soils by nitrogen fix-
ing microbial associations.

General Description:Evergreentree,
up to 150 ft. high, with long, slender
branches, which resemble a conifer.

Leaves: Dark green, reduced to
scalelike sheaths, surrounding
jointed cylindrical branches in
whorls, 6-8 scales per whorl.

Bark: Reddish brown to grey; rough,
brittle and peeling; smooth in young
growth.

Flowers: Staminate spikes '/2-2 in.
long, pistilate spikes globular.


Seed Capsule: Cone-like andwoody,
1/2-3/4 in. wide.

Seed Dispersal: Throughout the
year, primarily by wind, but cap-
sules will float.

Problem: Australian pine was intro-
duced into Florida in the late 1800s
for use as windbreaks and to provide
shade and lumber. It is a hardy, salt-
tolerant species, which has become
one of the three worst pest plants in
south Florida. Because of its fast
growth, it forms dense stands, which
crowd out native vegetation. Litter
produced under a stand of Austra-
lian pines inhibits growth of other
plants, and nitrogen fixing capabil-
ity may give it an additional com-
petitive advantage. Sensitivityto cold
temperatures limits it to areas south
of Orlando.

Biological Control: No biological
control research has been conducted.

Manual Removal: Seedlings, sap-


lings and small trees can be removed
manually. Kelly device facilitates
manual removal.

Mechanical Removal: If trees are
cut they will regrow from stumps if
not removed or treated with herbi-
cide. Follow cutting with herbicide
and/or manual removal to control
seedlings and root sprouts.

Physical Removal: Fire is some-
times effective in dense stands with
sufficient fuel on the ground. Large
trees usually resprout from bases.
Follow-up treatment may be neces-
sary.

Herbicides: Guidelines for initial
development of a herbicide control
program for Australian pine are
listed below. Always follow current
herbicide label instructionsfordeter-
mining rates ofapplication, approved
application sites, safety clothing, and
use precautions.


AUSTRALIAN PINE


(Casuarina spp.)


Herbicide Application Method


Application Method
Basal bark


Injection


Cut stump

Frill/Girdle

Foliar


Cut stump


Foliar


Soil applied


Comments
Use undiluted or as 2%-25% solution in diesel. Refer to herbicide label for
additional application instructions. Follow-up treatment may be necessary on large
trees.

Inject undiluted herbicide using special injection equipment.

Use undiluted herbicide or dilute 1:1 with water. Apply to cambium.

Use undiluted herbicide or dilute 1:1 with water.

Dilute in 50-400 gal. of water and include an approved nonionic surfactant in spray
mixture. Thorough coverage of foliage is important.

Use a formulation labeled for this purpose and apply to cambium.

Dilute and include surfactant as instructed on herbicide label.

Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter within 6 inches
of base with spot gun. Do not exceed 3 gal./acre. Willkilldesirable vegetation where
roots come in contact with the herbicide.


Herbicide
Garlon 4


Garlon 3A


2,4-D


Velpar L




















































Application Method
Frill/Girdle


Injection


Soil applied


Comments
Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter to frill. Do not
exceed 3 gal./acre.

Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter using special
injection equipment.

Can be applied by aerial application, backpack blower or by hand. Do not exceed 15
lbs./acre. Will kill desirable vegetation where roots come in contact with the herbicide.
For spot treatments use the following application rates:


Stem diameter (inches)
1/4-2
3-6
7-12


Soil applied

Soil applied


Ounces
1/4


Double above rates for Spike 40P.

Thoroughly mix 1 pound of product per gal. of water and apply 1 oz. of solution per
2-4 inch stem diameter. Keep agitated. Do not exceed 7.5 lb. product/acre. Will kill
desirable vegetation where roots come in contact with the herbicide.


Herbicide


Spike 40P


Spike 20P

Spike 80W


I I







Other Common Names: Florida
holly, Christmas berry.

Native Country: Brazil.

Habitat: Native of Brazil's tropical
coast; now found in most tropical
and subtropical regions of the world.
Brazilian pepper grows in moist to
moderately well drained soil of good-
to-poor fertility. Aggressive pioneer-
ing species on disturbed sites.

General Description: Dioecious, ev-
ergreen tree or shrub to 36 ft. high
with stiffly upright, thick, dense
branches.

Leaves: Odd pinnate, leaflets obo-
vate 1-2 in. long; smell of turpentine
when crushed.

Bark: Tan, gray; fairly smooth when
young. Rough, furrowed on older
trees.

Flowers: White, inconspicuous, uni-
sexual in dense terminal panicles,
sepals 1/25 in. long, petals 1/16 in. long.


Fruit: Clusters of red berries 1/5 in.
wide on female trees.

Seed Dispersal: Birds, raccoons,
opossums, cattle, deer.

Vegetative Reproduction: Root
sprouting after fire or frost defolia-
tion and by layering.

Problem: Brazilian pepper was intro-
duced into Florida in the late 1800s
for ornamental purposes. This small
tree is fast-growing and is a prolific
seed-producer. It is widely adapt-
able, and quickly invades disturbed
land such as roadsides, canal em-
bankments and abandoned farm-
land. It has taken over thousands of
acres of wetlands, hammocks,
pinelands and pastures. Once estab-
lished, it successfully competes for
light and space with other plants. It
has been suggested that Brazilian
pepper produces a chemical in its
leaves that gives it the ability to
suppress the growth of other plants.


Biological Control: Several insects
are currently being evaluated.

Manual Removal: Seedlings and
saplings can be hand pulled. If the
entire root system is not removed
resprouting usually occurs.

Mechanical Removal: Heavy equip-
ment is often used to clear land of
Brazilian pepper. Regrowth rapidly
occurs from the seed pool and veg-
etative fragments. Therefore, follow-
up control methods are necessary.

Physical Control: Fire will control
seedlings but mature trees (more
than 1 m high or 5 yrs. old) usually
resprout.

Herbicides: Guidelines for initial
development of a herbicide control
program for Brazilian pepper are
listed below. Always follow current
herbicide label instructions for deter-
mining rates ofapplication, approved
application sites, safety clothing, and
use precautions.


BRAZILIAN PEPPER


(Schinus terebinthifolius Raddi)


Application Method
Foliar


Basal bark


Injection


Cut stump

Frill/Girdle

Foliar


Cut stump

Soil applied


Comments
Dilution and rate of application depends on formulation. Refer to herbicide label.
Arsenal is soil active. Desirable vegetation can be killed if roots come in contact with
the herbicide.

Use undiluted or as 2%-25% solution in diesel. Refer to herbicide label for additional
application instructions. Follow-up treatment may be necessary on large trees.

Inject undiluted herbicide using special injection equipment.

Use undiluted herbicide or dilute 1:1 with water. Apply to cambium.

Use undiluted herbicide or dilute 1:1 with water.

Dilute in 50-400 gal. of water and include an approved nonionic surfactant in spray
mixture.

Dilute herbicide 1:1 in water and concentrate mixture on cambium.

Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameterwithin 6 inches
of base with spot gun. Do not exceed 3 gal./acre. Willkill desirable vegetation when
roots come in contact with the herbicide.


Herbicide
Arsenal


Garlon 4


Garlon 3A


Trooper

Velpar L




















































Herbicide


Application Method
Frill/Girdle


Injection


Spike 40P


Spike 20P


Soil applied


Soil applied


Spike 80W Soil applied


Comments
Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter to frill. Do not
exceed 3 gal./acre.

Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter using special
injection equipment.

Can be applied by aerial application, backpack blower or by hand. Do not exceed
15 Ibs/acre. Will kill desirable vegetation where roots come in contact with the
herbicide. For spot treatments use the following application rates:

Stem diameter (inches) Ounces
1/4-2 '/4
3-6 '/2
7-12 1


Double above rates for Spike 40P.


Thoroughly mix 1 pound of product per gal. of water and apply 1 oz. of solution per
2-4 inch stem diameter. Keep agitated. Do not exceed 7.5 lb. product/acre. Will kill
desirable vegetation where roots come in contact with the herbicide.







Other Common Names: Common
colubrina, latherleaf.

Native Country:Native to Old World
beaches from east Africa to India,
Malaysia, and Pacific islands.

Habitat: Coastal beach and dune
vegetation, coastal hammocks.

General Description: Rambling,
twining shrub.

Leaves: Dark green and lustrous
above, paler below, 11/2-31/2 in. long,
ovate or elliptic-ovate, serrate or cre-
nate-serrate.

Bark: Pale in color and somewhat
rough.

Flowers: Flowers greenish, 1/6 in. in
diameter, on 1/8 in. pedicels sub-
tended by minute bracts, in small
axillaryclusters on common peduncle
about 1/12 in. long. Sepals 1/12 in. long,
petals 1/12 in. long.


Fruit: Brown (orange when imma-
ture), trilocular, 3-grooved, 1/4-1/2 in.
wide.

Problem: Asiatic colubrina was in-
troduced into the Caribbean Islands
from Asia where it escaped from cul-
tivation, and then dispersed to coastal
Florida. It has floating seeds that are
transported by seawater. It is most
often found growing in the uplands-
submerged lands interface; the seeds
reach the uplands during spring and
storm tides. Asiatic colubrina can
form dense walls which are virtually
impenetrable. Its climbing growth
habit allows it to grow over the na-
tive vegetation canopy and can often
effectively shade out native flora. It
has been known to replace native
communities of buttonwood, man-
grove and mangrove fringe commu-
nities.

Biological Control: Biological con-
trol of this species has not been in-
vestigated.


Manual Removal: Twining stems
should be removed from desirable
vegetation where possible. Addi-
tional control measures are neces-
sary to kill rooted portions.

Mechanical Removal: Usually not
practical.

Physical Control: No information
available.

Herbicides: Guidelines for initial
development of a herbicide control
program for Asiatic colubrina are
listed below. Control with herbicide
is difficult due to its rambling habit
and difficulty in identifying the main
trunk. Always follow current herbi-
cide label instructions for determin-
ing rates of application, approved
application sites, safety clothing, and
use precautions.


ASIATIC COLUBRINA


(Colubrina asiatica (L.) Brongn.)


Application Method
Basal bark


Comments
Dilute to 2% in diesel


Herbicide
Garlon 4

















































'^



































13








Other Common Names: Paperbark
tree, punk tree, cajeput tree, white
bottlebrush tree.

Native Country: Australia and New
Guinea.

General Description: Tree usually
grows to 50 ft.

Habitat: Can tolerate most subtropi-
cal ecosystems with a preference for
seasonally wet sites, also flourishes
in standing water.

Leaves: Alternate, lanceolate, 12-
24 in. long, grey-green, smell of cam-
phor when crushed.

Bark: White, spongy, paper like.

Flowers: White in brushlike spikes.

Seed Capsules: Woody, numerous,
clustered on branches.

Seed Dispersal: Wind and water
dispersed.

Problem: Melaleuca was introduced
into south Florida in the early 1900s


forlandscapingpurposes, and to help
dry up what were then considered
useless swamps. Since its introduc-
tion, it has spread so rapidly that,
according to one survey, it now in-
fests 3 million acres. Melaleuca pro-
duces seed in 2 or 3 years after ger-
mination and a mature tree can
eventually store over 20 million
seeds. Fire, frost, herbicide applica-
tion or other stresses cause the cap-
sules to open and seed to be released.
In a few years a single tree can re-
lease millions of seeds that result in
impenetrable thickets. Melaleuca
threatens to permanently replace
natural plant communities and the
animals that live in them.

Biological Control: Potential bio-
logical controls have been identified
that should aid in future melaleuca
management. Greatest interest is in
insects that destroy seeds and seed-
lings in order to prevent or reduce
the spread of melaleuca.

Manual Removal: Seedlings and
saplings can be hand removed but
remaining root fragments usually
resprout.


Mechanical Removal: Mechanical
removal is used for mature melaleuca
trees. Since damage to the trees
causes subsequent seed release, any
seed capsules should be destroyed.
Follow-up control measures are nec-
essary to prevent reinvasion and
resprouting.

Physical Control: Fire with suffi-
cient fuel will control small (> 2 ft.)
seedlings, but mature trees are fire
tolerant. Fire usually results in mas-
sive seed release, thus increasing
the problem. Rising water level fol-
lowing seed release has been found
to control newly germinated seed-
lings.

Herbicides: Guidelines for initial
development of a herbicide control
program for melaleuca are listed
below. Always follow current herbi-
cide label instructions for determin-
ing rates of application, approved
application sites, safety clothing, and
use precautions.


MELALEUCA


(Melaleuca quinquenervia (Cav.) Blake)


Herbicide
Arsenal


Application Method
Frill/Girdle


Foliar


Banvel 720 Foliar


Garlon 3A


Rodeo


Cut stump

Frill/Girdle
Foliar



Frill/Girdle


Foliar


Comments
Dilution and rate of application depend on formulation used. Refer to herbicide label.
Arsenal is soil active. Desirable vegetation can be killed if roots come in contact with
the herbicide.
Seedlings are more susceptible to foliar applications than larger trees. Large mature
trees with dense crowns may not be effectively controlled.
Seedlings only. Dilute in 20-100 gal. of water.
Cut stump close to ground to minimize resprouting. Use undiluted herbicide or dilute
1:1 with water. Apply to cambium.
Use undiluted herbicide or dilute 1:1 with water.
Seedlings are more susceptible to foliar applications than larger trees. Large mature
trees with dense crowns may not be effectively controlled. Dilute in 50-400 gal. of
water and include an approved nonionic surfactant in spray mixture. Do not exceed
3 gal. of herbicide per acre.
Make cuts no more than 2 in. apart, spaced evenly around trunk. Apply .2 tsp. (12
drops) undiluted herbicide to each cut. Application should be made during periods
of active growth and full leaf expansion. Trees growing in flooded conditions are
tolerant.
Dilute 11/2 gal. herbicide in 100 gal. water and include an approved surfactant. Spray
foliage to wet. Do not exceed labeled rate per acre. Seedlings are more susceptible
to foliar applications than largertrees. Large mature trees with dense crowns may not
be effectively controlled.

















































Herbicide Application Method Comments
Spike 40P Soil applied Can be applied by aerial application, backpack blower or by hand. Do not exceed 15
Ibs./acre. Willkill desirable vegetation where roots come in contact with the herbicide.
For spot treatments use the following application rates:
Stem diameter (inches) Ounces
1/4-2 1/4
3-6 1/2
7-12 1
12+ 2
Spike 20P Soil applied Double above rates for Spike 40P.
Spike 80W Soil applied Thoroughly mix 1 pound of product per gal. of water and apply 1 oz. of solution per
2-4 inch stem diameter. Keep agitated. Do not exceed 7.5 lb. product/acre. Will kill
desirable vegetation where roots come in contact with the herbicide.
Velpar L Soil applied Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter
within 6 inches of base with spot gun. Do not exceed 3 gal./acre. Will kill desirable
vegetable where roots come in contact with the herbicide.
Frill/Girdle Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter
to frill. Do not exceed 3 gal./acre.
Injection Apply .4 tsp. (24 drops) of undiluted herbicide per inch of tree diameter
using special injection equipment.








APPENDIX A: METRIC / ENGLISH
EQUIVALENTS USED IN THIS CIRCULAR

English Unit Metric Equivalent
1 tsp. 5.00 ml
1 oz. 29.57 ml
1 gal. 3.791
1 in. 2.54 cm
1 ft. 0.30 m
1 acre 0.41 ha


APPENDIX B: HERBICIDES MENTIONED IN THIS CIRCULAR


Trade Name
Arsenal



Banvel 720


Garlon 3A

Garlon 4

Spike 40P

Spike 20P

Spike 80W

Rodeo

Trooper

Velpar L


Common Name
Imazapyr


2,4-D

2,4-D+
Dicamba

Triclopyr

Triclopyr

Tebuthiuron

Tebuthiuron

Tebuthiuron

Glyphosate

Dicamba

Hexazinone


Chemical Name
Isopropylamine salt of 2-[4,5- dihydro-4-methyl-4-(1-methylethyl)- 5-
oxo-1H-imidazol-2-yl]-3- pyridinecarboxylic acid

2,4-dichlorophenoxy-acetic acid

Dimethylamine salt of 2,4-dichlorphenoxy- acetic acid + dimethylamine
salt of 3,6-dichloro-o-anisic acid

Triethylamine salt of 3,5,6- trichloro-2-pyridinyloxyacetic acid

Butoxy ethyl ester of 3,5,6- trichloro-2-pyridinyloxyacetic acid

N-[5-(1,1-dimethylethyl)-1,3,4- thiadiazol-2-yl]-N,N'dimethylurea

same as above

same as above

Isopropylamineamine salt of N-(phosphonomethyl) glycine

Dimethyl amine salt of 3,6-dichloro- o-anisic acid

3-cyclohexyl-6-(dimethylamino)-1- methyl-1,3,5-triazine-2,4( 1H,3H)-
dione


--


--




















































































Printed 1990.

COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, John T. Woeste,
director, In cooperation with the United States Department of Agriculture, publishes this Information to further the purpose of the May 8 and
June 30, 1914 Acts of Congress; and Is authorizes to provide research, educational Information and other services only to Individuals and
Institutions that function without regard to race, color, sex, age, handicap or national origin. Single copies of extension publications (excluding
4-H and youth publications) are available free to Florida residents from county extension offices. Information on bulk rates or copies for out-
of-state purchasers is available from C. M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesvllle, Florida
32611. Before publicizing this publication, editors should contact this address to determine availability.









HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida