Group Title: Circular
Title: Exotic woody plant control
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Permanent Link: http://ufdc.ufl.edu/UF00078707/00001
 Material Information
Title: Exotic woody plant control
Series Title: Circular
Physical Description: 16 p. : ill. (some col.) ; 28 cm.
Language: English
Creator: Langeland, Ken
Langeland, Kenneth A
Exotic Pest Plant Council -- Publications Committee
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Florida Cooperative Extension Service
Place of Publication: Gainesville, Fla.
Gainesville
Publication Date: 1990
 Subjects
Subject: Woody plants -- Integrated control -- Florida   ( lcsh )
Woody plants -- Control -- Florida   ( lcsh )
Plant introduction -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: Ken Langeland, editor.
General Note: Cover title.
General Note: "Prepared by Exotic Pest Plant Council, Publications Committee"--Verso cover.
 Record Information
Bibliographic ID: UF00078707
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltuf - AHK8458
oclc - 22999356
alephbibnum - 001584516

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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








UNIVERSITY OF

FLORIDA

EXTENSION
Institute of Food and Agricultural Sciences


Exotic Woody Plant Control1
Ken Langeland, Editor2


INTRODUCTION

Extensive urbanization in Florida has led to the
introduction of a great number of exotic (non-native)
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 endeavor includes
management, or elimination where possible, of


Circular 868


introduced vegetation. Several very aggressive
introduced plants have already replaced native Florida
plant communities in some areas, thereby drastically
changing 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
coordinate efforts of various agencies into developing
management programs and increasing public
awareness. This circular is an example of those
efforts. It presents current methods for control of
Australian pine, Brazilian pepper, Asiatic colubrina
and melaleuca that have been tested and compiled by
members of the EPPC. Management programs
include the use of manual removal, mechanical
removal, physical controls and herbicides, 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 treatments
listed have been found effective under certain
circumstances. However, since choice of herbicide


1. This document is Circular 868, one of a series of the Department of Environmental Horticulture, Florida Cooperative Extension Service, Institute of Food
and Agricultural Sciences, University of Florida. Date reviewed: June 1999. Please visit the EDIS Web site at http://edis.ifas.ufl.edu.
2. Ken Langeland, Professor, Aquatic Weeds and Plant Management, Department of Fisheries and Aquatic Sciences, Cooperative Extension Service, Institute
of Food and Agricultural Sciences, University of Florida, Gainesville, 32611.

The Institute of Food and Agricultural Sciences is an equal opportunitylaffirmative action employer authorized 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.
For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative
Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.






Exotic Woody Plant Control 2


application will depend upon environmental
conditions and personal preference, they are not
ranked in this publication.

TYPES OF CONTROL METHODS

Prevention

The importation and spread of noxious exotic
vegetation 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
environmental restraints, competing species,
herbivores (e.g., insects) and pathogens. When plants
are introduced into new areas, they often have a
competitive advantage over native plants because
natural controls of the introduced plants are not
present. This competitive advantage may allow
introduced plants to cause problems, 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 quarantined 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 suppress
growth of the pest. (4) If necessary, biological
control agents are collected from established
populations and moved to new locations.

Classical biological control has been used
successfully for many years. Probably the first effort
was the use of an insect (Dactylopius ceylonicus
Green) to control prickly pear cactus (Opuntia
vulgaris Mill.) in southern India during the 1860's.
More recently, alligatorweed flea beetle (Agasicles
1'-'7, I'il and alligatorweed stem boring moth
(Vogtia malloi) have successfully suppressed
alligatorweed (Alternanthera philoxeroides (Mart.)
Griseb.) in the southeastern United States.

Biological control agents have not yet been
introduced 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 of these 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.

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






Exotic Woody Plant Control 3


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

removal is not effective for control of Australian
pine, Asiatic colubrina, 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. Mechanical
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 programs (e.g., timing of herbicide
applications with flooding) is important.

Herbicides

Regulations

Herbicides are a commonly used method of
managing 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 813/626-5143


Orlando 407/423-0673
West Palm Beach 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 904/796-7211
St. Johns River WMD 904/328-8321
South Florida WMD 407/686-8800

A basic knowledge ofherbicide technology and
application techniques is necessaryfor safe and
effective use of herbicides. For this reason, state
agencies and federal agencies require personnel
involved in herbicide application to be certified by the
Florida Department ofAgriculture and Consumer
Services (FDACS). It is strongly advised that any
individual who practices herbicide application be
certified by FDACS. The Universirty of Florida
Institute of Food and Agricultural Sciences provides
training and ;, i, ig for certification ofpesticide
applicators. For information regarding pesticide
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 physiological reasons they
do not move extensively within the plant and are
effective only where they contact plants. They are
generally more effective on annual, herbaceous
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 absorbed 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 asfoliar active herbicides.
Some soil active herbicides, tebuthiuron for example,
are absorbed only by plant roots. Other systemic
herbicides, such as glyphosate and triclopyr, are






Exotic Woody Plant Control 4


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
correctly, systemic herbicides act slowly compared to
contact 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.

Herbicde 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 controlling woody plants are broad
spectrum and care must be taken to avoid damage to
nontarget, desirable vegetation. However, broad
spectrum herbicides can be used for selective weed
control if special application techniques, such as fall
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. Herbicide selectivity can be
affected by the rate of application and growth stage of
plants. Factors that affect susceptibility 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 herbicides 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 in to
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
herbicide labels such as glyphosate have
precautionary statements to this effect. The
applicator should be aware of potential weather
conditions and should schedule applications
accordingly.

Wind

Wind can affect herbicide applications in several
ways. Foliar herbicide application during excessive
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, which
can result in poor control. Windy conditions should be
avoided when making foliar herbicide applications.






Exotic Woody Plant Control 5


Herbicide Formulations


Low temperature may affect herbicide 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 important factor in
the performance of tank-mixed herbicide applications
because some herbicides can be inactivated by
suspended particles, dissolved organic materials and
water hardness. Always take the following
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.


A herbicide formulation usually consists of the
herbicide 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 characteristics of the spray solution. These
special ingredients usually improve the safe handling,
measuring, and application of the active ingredient.

Water soluable 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 concontain a mixture of petroleum
solvents and emulsifiers that allow an insoluble or
low solubility herbicide to mix with water. EC's
require little agitation. They cause minimum
equipment wear because they are nonabrasive. EC's
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,
constant tank agitation is important when using
flowables. 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.


Temperature






Exotic Woody Plant Control 6


Granule (G) and pellet (P)

Granules and pellets range from 1%-40% active
ingredient. Granules are convenient for spot
treatments, are ready to use, reduce drift hazards, and
can be easily applied. The disadvantage of granules
is the sometimes high expense per pound of active
ingredient.

Wettable powder (WP)

Another common dry formulation is the wettable
powder. WP formulations resemble a fine dust and
generally contain greater than 50% active ingredient.
When mixed with water, agitation is required to keep
the insoluble particles of a wettable powder in
suspension. The advantages of WPs are the lower
cost, ease of handling, and ease of measuring. Some
disadvantages of WPs are the abrasion 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
disuse of the product, and precautions for the user
and the environment. The label is the law. It is
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 may cause
unwanted results such as damage to nontarget
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
informaabout the product and should be read
;hi 1, ii,,ihhy' and carefully before each use. Before
applying a herbiread 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 labeled 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
routinely. You may have missed ,i lii,,r 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 equipment or
backpack sprayers are usually used. The herbicide 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 usumade 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






Exotic Woody Plant Control 7


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 sometimes 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 herbicides, 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
treatments are slow and labor intensive but
sometimes necessary in mixed communities to kill
noxious vegetation and minimize impact to desirable
vegetation. To further minimize potential impact to
desirable vegetation cuts can be wrapped with
masking tape to prevent rainfall from washing
herbicide to the soil.

Injection

Special equipment (available from agricultural
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 spreadspecially
designed blowers, or aerially. Soil-applied, liquid,
flowable or wettable powder herbicide formulacan 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 keeptrack 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 of limiting herbicide contact
with nontarget vegetation and personal contact.


Figure 2. Basal bark applications are made by applying
herbicide directly to the bark around the circumference 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.


f
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 masking tape to
prevent rainfall from washing herbicide to the soil.







Exotic Woody Plant Control 8


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.

Botanical Descriptions and Control
Recommendations for Austrailian Pine,
Brazilian Pepper, Asiatic Columrina, and
Maleluca

Austrailian Pine

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. Austrailian pine is capable of colonizing
nutrient-poor soils by nitrogen fixing microbial
associations.

General Description: Evergreen tree, 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 1/2-2 in. long,
pistilate spikes globular.

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

Seed Dispersal: Throughout the year, primarily
by wind, but capsules will float.

Problem: Australian pine was introduced into
Florida in the late 1800's 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 Australian pines inhibits growth of other plants,
and nitrogen fixing capability may give it an
additional competitive advantage. Sensitivity to
cold temperatures limits it to areas south of Orlando.

Biological Control: No biological control
research has been conducted.

Manual Removal: Seedlings, saplings 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
herbicide. Follow cutting with herbicide and/or
manual removal to control seedlings and root sprouts.

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

Herbicides: Guidelines for initial development
of a herbicide control program for Australian pine are
listed below. Alwaysfollow current herbicide label
instructionsfor deterrates ofapplication, approved
application sites, safety cl, hu.inr. and use precautions.
(Figure 6)


Figure 6.







Exotic Woody Plant Control 9


Brazilian Pepper

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 pioneering species on disturbed sites.

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

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

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

Flowers: White, inconspicuous, unisexual 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 defoliation and by layering.

Problem: Brazilian pepper was introduced into
Florida in the late 1800's for ornamental purposes.
This small tree is fast-growing and is a prolific
seed-producer. It is widely adaptable and quickly
invades disturbed land such as roadsides, canal
embankments and abandoned farm It has taken over
thousands of acres of wetlands, hammocks, pinelands
and pastures. Once established, 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 equipment is
often used to clear land of Brazilian pepper.
Regrowth rapidly occurs from the seed pool and
vegetative 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. Alwaysfollow current herbicide
label instructionsfor determining rates of
application, approved application sites, safety
(I ili,,i,. and use precautions. (Figure 7)


N IP..


U


'-- ,
*-- Ni


1'e


Figure 7.



Asiatic Colubrina

Other Common Names: Common colubrina,
latherleaf.

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







Exotic Woody Plant Control 10


Table 1. AUSTRALIAN PINE (Casuarina spp.)


Herbicide Application
Method
Garlon 4 Basal bark


Garlon 3A Injection

Cut stump

Frill/Girdle

Foliar


2,4-D


Cut stump


Foliar


Velpar L


Soil applied


Frill/Girdle


Injection


Spike 40P 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 herbcide 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. WII kill desirable
vegetation where roots come in contact with the herbicide.

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)
1/4-2
3-6
7-12
12+


Spike 20P Soil applied


Spike 80W Soil applied


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 Ib. product/acre. WII
kill desirable vegetation where roots come in contact with the herbicide.


Table 2. Brazilian Pepper (Schinus terebinthifolius Raddi)

Herbicide Application Comments
Method
Arsenal Foliar 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.
Garlon 4 Basal bark 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.


Ounces
1/4
1/2
1
2







Exotic Woody Plant Control 11

Table 2. Brazilian Pepper (Schinus terebinthifolius Raddi)

Garlon 3A Injection Inject undiluted herbicide using special injection equipment.

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

Frill/Girdle Use undiluted herbcide or dilute 1:1 with water.

Foliar Dilute in 50-400 gal. of water and include an approved nonionic surfactant in spray
mixture.
Trooper Cut stump Dilute herbicide 1:1 in water and concentrate mixture on cambium.

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
vegetation 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.

Spike 40P Soil applied 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 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 Ib. Product/acre. Will
kill desirable vegetation where roots come in contact with the herbicide.


Habitat: Coastal beach and dune vegetation,
coastal hammocks.

General Description: Rambling, twining shrub.

Leaves: Dark green and lustrous above, paler
below, 1 1/2-3 1/2 in. long, ovate or elliptic-ovate,
serrate or crenate-serrate.

Bark: Pale in color and somewhat rough.

Flowers: Flowers greenish, 1/6 in. in diameter,
on 1/8 in. pedicels subtended by minute bracts, in
small axillary clusters on common peduncle about
1/12 in. long. Sepals 1/12 in. long, petals 1/12 in.
long.


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

Problem: Asiatic colubrina was introduced into
the Caribbean Islands from Asia where it escaped
from cultivation 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 native vegetation canopy and can often
effectively shade out native flora. It has been known
to replace native communities of buttonwood,
mangrove and mangrove fringe communities.







Exotic Woody Plant Control 12


Biological Control: Biological conofthis
species has not been investigated.

Manual Removal: Twining stems should be
removed from desirable vegetation where possible.
Additional control measures are necessary 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 herbicide label
instructions for determining rates of application,
approved application sites, safety c II nl,, and use
precautions. (Figure 8)





i .-
.7- \. .

I


': r







Figure 8.

Table 3. Asiatic Colubrina (Colubrina asiatica (L.)
Brongn.)
Herbicide Application Comments
Method
Garlon 4 Basal bark Dilute to 2% in diesel


Melaleuca

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 subtropiecosystems
with a preference for seasonally wet sites, also
flourishes in standing water.

Leaves: Alternate, lanceolate, 12 in. long,
grey-green, smell of camwhen 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 1900's for landscaping purposes,
and to help dry up what were then considered useless
swamps. Since its introduction, it has spread so
rapidly that, according to one survey, it now infests 3
million acres. Melaleuca produces seed in 2 or 3
years after germination and a mature tree can
eventually store over 20 million seeds. Fire, frost,
herbicide application or other stresses cause the
capsules to open and seed to be released. In a few
years a single tree can release 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 biological controls
have been identified that should aid in future
melaleuca management. Greatest interest is in insects
that destroy seeds and seedlings 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 necessary to prevent reinvasion and
resprouting.







Exotic Woody Plant Control 13

Physical Control: Fire with sufficient fuel will
control small (> 2 ft.) seedlings, but mature trees are
fire tolerant. Fire usually results in massive seed
release, thus increasing the problem. Rising water
level folseed release has been found to control newly
germinated seedlings.

Herbicides: Guidelines for initial development
of a herbicide control program for melaleuca are
listed below. Always follow current herbicide label
instructionsfor determinrates of application,
approved application sites, safety c h, iI h, and use
precautions. (Figure 9)






7-~c

....,-I..








Figure 9.

Table 4. Melaleuca (Melaleuca quinquenervia (Cav.) Blake)

Herbicide Application Comments
Method
Arsenal Frill/Girdle 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.

Foliar Seedlings are more susceptible to foliar applications than larger trees. Large
mature trees with dense crowns may not be effectively controlled.

Banvel 720 Foliar Seedlings only. Dilute in 20-100 gal. of water.

Garlon 3A Cut stump Cut stump close to ground to minimize resprouting. Use undiluted herbicide or
dilute 1:1 with water. Apply to cambium.

Frill/Girdle Use undiluted herbcide or dilute 1:1 with water.

Foliar 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.







Exotic Woody Plant Control 14


Table 4. Melaleuca (Melaleuca quinquenervia (Cav.) Blake)
I


Table 5.


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. 3.79 I
1 in. 2.54 cm
1ft. 0.30 m
1 acre 0.41 ha
Appendix B: Herbicides Mentioned in this Circular

Trade Name Common Name Chemical Name
Arsenal Imazapyr Isopropylamine salt of
2-[4,5-d i hyd ro-4-methyl-4-(1-methylethyl)-5-oxo-1 H-imidazol-2-yl]-3-
pyridinecarboxylic acid
2,4-D 2,4-dichlorophenoxy-acetic acid
Banvel 720 2,4-D+ Dicamba Dimethylamine salt of 2,4-dichlorphenoxy-acetic acid + dimethylamine salt of
3,6-dichloro-o-anisic acid


Rodeo Frill/Girdle 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.
Foliar Dilute 1 1/2 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 larger trees. Large mature trees with dense
crowns may not be effectively controlled.
Spike 40P Soil applied 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 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 Ib. 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
vegetation 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.







Exotic Woody Plant Control 15

Table 5.

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

Garlon 4 Triclopyr Butoxy ethyl ester of 3,5,6-trichloro-2-pyridinyloxyacetic acid
Spike 40P Tebuthiuron N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N, N'dimethylurea

Spike 20P Tebuthiuron same as above

Spike 80W Tebuthiuron same as above
Rodeo Glyphosate Isopropylamineamine salt of N-(phosphonomethyl) glycine
Trooper Dicamba Dimethyl amine salt of 3,6-dichloro-o-anisic acid

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




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