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8 TREE CARE INDUSTRY – MAY 2014

By Patrick Parker, CTSP

Last fall, in response to a growing

interest in the subject, TCIA organ-

ized a tree injection summit aimed

at “combining cutting edge presentations,

demonstrations, and practical application

discussions related to tree injection ... cov-

ering everything from the deeply scientific

to the practical.” For all intents and pur-

poses, the November 13, 2013, event, held

in conjunction with TCI EXPO in

Charlotte, North Carolina, and hosted at

the Bartlett Tree Research Lab in

Charlotte, did just that.

Tom Smiley, Ph.D., of the Bartlett

Research Lab was the first presenter on the

agenda and gave a fascinating presentation

outlining the history of tree injections and

laid out five goals to be accomplished

when using modern day tree injections.

According to Smiley, tree injections should

be:

u Safe (for the public, the applicator

and the environment)

u Quick and easy to perform

u Minimally damaging to the tree

u Able to provide a long residual/effi-

cacy

u Affordable

Smiley also displayed a longitudinal sec-

tion from the base of a tree trunk that

clearly showed why injections should be

made in the area of the trunk flares (root

collar) as opposed to higher up into the

trunk tissue. The section shows a much

larger amount of conducting sapwood in

the trunk flares than in the trunk tissues.

This is important for proper uptake of

injected materials and even distribution of

the materials throughout the tree canopy.

(Figure 1)

Smiley also clarified the difference

between injections and infusions as fol-

lows: an infusion relies entirely on

transpirational movement of introduced

materials, while injections employ an out-

side force to introduce and partially

distribute material. Given this definition all

of the methods discussed throughout the

day were true injections.

Rex Bastian, Ph.D., of The Davey Tree

Expert Company, talked about the deci-

sion-making process that should be used

when considering whether or not to use

tree injections. Bastian presented an

extremely detailed flow-chart of the deci-

sion-making process to be used when

determining the best course of action when

treating any particular issue, whether using

injections or not. (Figure 2)

Given the wide range of treatment

options available for various pests and con-

ditions, the flow chart helps the practicing

arborist to make sound decisions when

managing trees. The flow chart is laid out in

Injection system demos were a big hit during the Tree Injection Summit in Charlotte in November 2013. Here, Rob Gordon from Arborjet discusses where different injection systems can beused most effectively.

Figure 1: A longitudinal section from the base of a trunkthat shows why injections should be made in the rootflares, where there is a much larger amount of conduct-ing sapwood than in the trunk tissues. Courtesy of TomSmiley, Bartlett Labs.

a very logical fashion and should be helpful

for those who are familiar with the different

options available for treating trees. Most

arborists are concerned about the wounding

caused by the injection process or by the

materials that are being injected, and these

need to be considered when deciding on the

best treatment option for any particular con-

cern. The bottom line when making

decisions regarding whether or not to inject

is, “Do the benefits of injection outweigh

the potential risks to the tree?”

Research on tree response to wounding

from stem or root flare injection of chemi-

cal treatments was reviewed by Kevin T.

Smith, Ph.D., of the U.S. Forest Service.

Smith described that the history of tree

injection came close behind the invention

of hypodermic syringes for human medi-

cine.

“From the beginning of experimental

injection, tree care practitioners were con-

cerned about the effects of wounding from

injection,” Smith says. He cited the land-

mark research studies in tree injection and

outlined some of the challenges associated

with performing this type of research.

“A big challenge is that during long-term

studies, the available techniques and chem-

ical formulations change, potentially

making studies obsolete by the time they

are completed,” Smith says. “Another

challenge is to find appropriate test trees in

‘real world’ settings that can be dissected

to see the actual effects of injection on tree

physiology and health.”

What is absolutely essential to under-

stand about tree injections, according to

Smith, is an understanding of how trees

compartmentalize the specific injection

treatment. Compartmentalization is the

boundary-setting process that resists the

spread of infection and the loss of healthy

function in tree tissues. He advised practic-

ing arborists that the size of the wound can

be much greater than the size of the injec-

tion site.

“Modern techniques usually use small

injection sites that the tree should be able

to handle. However, some chemical for-

mulations are phytotoxic and kill tissue far

beyond the small-diameter injection site.”

Smith says. “Other techniques may use a

small injection site but cause the bark to be

pulled away from the stem, resulting in a

much larger wound and loss of healthy

wood and cambium.”

Smith says he is encouraged that some

injection companies are paying attention to

the effects of wounding by including tree

dissection in research tests. Some practi-

tioners are taking the time to dissect and

observe the internal effects of injection

when they have the opportunity to do so.

He concluded with the concept that the

decision to treat with chemical injections

TREE CARE INDUSTRY – MAY 2014 9

Figure 3: Wound response is clearly delineated in thisAcer rubrum sample. Courtesy of Kevin T. Smith, U.S.Forest Service.

Figure 2: This flow-chart outlines the decision-making process to be used when determining the best course of actionwhen treating any particular issue, whether using injections or not. Courtesy of Rex Bastian, Davey Tree.

should be part of a decision matrix, similar

in concept to the flowchart proposed by

Rex Bastian. That matrix or flowchart,

according to Smith, would consider treat-

ment effectiveness, the consequences of

doing nothing, the monetary cost of treat-

ment as well as the social cost (acceptance)

of the treatment, availability of alternative

treatments, length of treatment cycle, and

as well as the concern for phytotoxicity as

part of the tradeoffs in making the decision

to inject.

Beyond the obvious aspects of wounding

the tree to perform the injection is the con-

sideration of how the introduced material

may adversely impact the tree as well.

Bruce Fraedrich, Ph.D., of the Bartlett Tree

Research Lab, addressed this issue outlin-

ing some of the latest information available

regarding the use of various fungicides in

tree injections. This included a review of

the fungicides available today for tree

injection and expected results for each of

these products when used at differing rates.

These fungicides include: benzimidazoles

(e.g. Arbotect and Fungisol), triazoles

(Alamo and other propiconazole containing

fungicides), phosphites, and even antibi-

otics (bactericides) such as oxytetracycline.

He explained that the pH and solubility

of the materials injected can have negative

impacts to tree health including bark crack-

ing, death of cambial and vascular tissues,

and phytotoxic reactions in shoots and

foliage. Some of these impacts can be

reduced by increasing the amount of water

used with the injection, however, these fac-

tors need to be understood and considered

when new materials are being developed

for tree injections as well as when the deci-

sion to inject is made.

One source for more information that

10 TREE CARE INDUSTRY – MAY 2014

Circle 7 on RS Card or visit www.tcia.org/Publications

Roger Webb, presi-dent of Tree Tech,demonstrates TreeTech’s capsule-typeinjection system,which requiresdrilling, beforeexplaining theadvantages of a newcapsule design.

The bottom line whenmaking decisions regard-ing whether or not toinject is, “Do the benefitsof injection outweigh thepotential risks to thetree?”

Circle 20 on RS Card or visit www.tcia.org/Publications

12 TREE CARE INDUSTRY – MAY 2014

Fraedrich referenced is the article,

“Fungicide Injections to Control Dutch

Elm Disease: Understanding Options,” by

Linda Haugen and Mark Stennes in the

June 1999 edition of Plant Diagnosticians

Quarterly: PDQ 1999 20(2): 29-38. This

article is readily available from several

sources on the Internet.

Chris Williamson, Ph.D., of the

University of Wisconsin gave a similar

Circle 40 on RS Card or visit www.tcia.org/Publications

Jerry Pulley demonstarates Mauget’s capsule stylemicroinjections.

TCIA’s Tree Injection Summit held in

Charlotte last November was so

popular we’re doing it again. The second

Tree Injection Summit will be May 29,

2014, from 8 a.m. to 4:30 p.m., at the Los

Angeles County Arboretum and

Botanical Garden in Arcadia, California.

Space is limited to the first 80 registrants.

This summit will again combine cut-

ting-edge presentations, demonstrations

and practical application discussions

related to tree injection. Covering every-

thing from the deeply scientific to the

practical, all aspects of tree injection

will be reviewed. A panel discussion

will round out the summit.

Refreshments and lunch are included. In

addition, attendees can earn 7.25 CEUs.

Speakers and panelists include, but are

not limited to: Len Burkhart, Davey Tree;

Bruce Fraedrich, Bartlett Tree Research

Labs; Kevin Smith, USFS; Joel Spies,

Rainbow Treecare Scientific

Advancements; Nathan E. Dodds,

Mauget; Eric Bristol, Arborjet; Chip

Doolittle, ArborSystems; and, Roger

Webb, Tree Tech Microinjection Systems.

Sponsors include Rainbow Treecare

Scientific Advancements, Mauget,

Arborjet, ArborSystems, and Tree Tech.

Cost is $90 for TCIA members, and

$125 for non-members. Register today

by calling TCIA at 1-800-733-2622, or

visit the Training Center at www.tcia.org.

TCIA to Host Second Tree Injection Summit

TREE CARE INDUSTRY – MAY 2014 13

overview of the insecticides available for

tree injections and other treatment methods.

This included some very new chemistry

being used to address insect issues such as

invasive species, and he included some

information available from his own arthro-

pod management tests that have been

published but not peer reviewed. If you are

not familiar with such materials as chlo-

rantraniliprole (Acelepryn), cyantraniliprole

(new active ingredient), indoxacarb

(Provaunt), dinotefuran (Safari, Transtect,

Zylam), and thiamethoxam (Meridian) for

use as insecticides, you need to educate

yourself on how these materials can be used

and what the expected results and conse-

quences are of their use.

For more information about the projects

Williamson is working on, check the web-

page for his lab at the University of

Wisconsin, Madison at http://labs.rus-

sell.wisc.edu/williamsonlab/.

Phil Lewis, Ph.D., works for the

USDA on the Asian longhorned beetle

(ALB) and emerald ash borer (EAB)

programs. He gave an overview of vari-

ous tree injection equipment and meth-

ods and highlighted key modifications

and successes in injection methodology

from his experience in the ALB program,

which has treated over 1.2 million trees

over the last 14 years. Best methods and

techniques for soil and trunk injection

were also discussed.

Demos

Demonstrations by five manufacturers of

injection systems were carried out in the

afternoon by performing injections using

water or fertilizer on small red maples on the

Circle 5 on RS Card or visit www.tcia.org/Publications

Shawn Bernick from Rainbow Treecare Scientific demonstrates their latest injection system, the iQ tree infuser. This elec-tronically controlled injection system generated quite a buzz as it was the first time that it had been demonstrated.

grounds of the Bartlett Tree Research Lab.

Mauget demonstrated their capsule style

microinjections that many arborists are

familiar with. Mauget has made some

recent changes to their capsule design and

requires drilling to perform the injection.

ArborSystems demonstrated the use of

the Wedgle Direct-Inject system using the

WedgeCheck plug. This injection method-

ology uses the WedgeCheck punch to

remove a small cylinder of bark (no

drilling required). The WedgeCheck plug

is then inserted into the bark and the injec-

tion is made through the plug, which is

then left in the tree.

Tree Tech Microinjection Systems,

another capsule type injection system that

requires drilling, was demonstrated and the

advantages of their new capsule design

were explained.

Arborjet demonstrated and reviewed the

various injection equipment systems that

they have available (the Tree IV, the

Quickjet, and the Viper). All three systems

require drilling and the use of the

Arborplug, which remains in the tree after

the injection. They also described where

each system could be used most effectively

and the advantages of one system over

another for different applications (conifer

vs. deciduous, high volume vs. low volume,

and small scale vs. large scale treatments).

Rainbow Scientific demonstrated their

latest injection system the iQ tree infuser.

This electronically controlled injection

system generated quite a buzz as it was the

first time that it had been demonstrated

publicly. This system requires drilling of

the tree, but does not use any kind of plug.

Pressure and dosage for each injection can

be set by the user with the electronic con-

troller. There are also other versions of this

system in development for use in different

situations, so this system is one to watch to

see what they will come up with next.

For more information regarding the

equipment options, available products,

pests/conditions treated, application proce-

dures, and contact information please visit

each manufacturer’s website.

Patrick Parker, CTSP, is director ofplant health care for SavATree in BedfordHills, New York.

14 TREE CARE INDUSTRY – MAY 2014

Chip Doolittle from Arborsystems demonstrates the Wedgle Direct-Inject system, which uses the WedgeCheck punch toremove a small cylinder of bark.

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