HomeMy WebLinkAbout120715_ca09Q \ 615 Sheridan Street
eh nn Port Townsend, WA 98368
C www.JeffersonCountyPublicHealth.org
Health
Consent Agenda
October 27, 2015
JEFFERSON COUNTY
BOARD OF COUNTY COMMISSIONERS
AGENDA REQUEST
TO: Board of County Commissioners
Philip Morley, County Administrator
FROM: Jared Keefer, Environmental Health & Water Quality Manager
Tami Pokorny, Environmental Health Specialist II
DATE: v,
SUBJECT: Agenda Item — Permission to Enter and Waiver of Liability
Agreement for Knotweed Control with Hood Canal Salmon
Enhancement Group for Knotweed Control; January 1, 2016 —
December 31, 2017; $0
STATEMENT OF ISSUE:
Jefferson County Public Health is requesting Board approval for Permission to Enter and
Waiver of Liability Agreement, Knotweed Control with Hood Canal Salmon Enhancement
Group, Knotweed Control Project; January 1, 2016 — December 31, 2017; $0
ANALYSIS/STRATEGIC GOALS:
Staff requests approval of an agreement with the Hood Canal Salmon Enhancement Group
(HCSEG) to allow the HCSEG and its agents, contractors, cooperators and employees to
enter onto Jefferson County -owned properties to perform activities to eradicate and/or
control knotweed (Polygonum spp.). The agreement also grants permission to the
Washington Department of Agriculture to access the properties for the purpose of monitoring
the success of eradication efforts.
The target properties include the following parcels (Assessor Parcel Numbers):
Bia Quilcene River:
702234002,991200202,991200204,991200205,991200601,991200609,991201102,
991201401,991201402,991201403,991201405,991201903,991202105
Dosewallips River:
602342001, 602343001, 602343010, 602343012, 602343013, 602343014, 602344014,
602344022,966900034,966900035,966900036,966900046,966900231
Since 2008, the Hood Canal Salmon Enhancement Group (HCSEG), in coordination with
regional partners, has been working with land owners to conduct surveys and treatment
Community Health
Environmental Health
Developmental Disabilities
Wafer Quality
360-385-9400
360-385-9444
360-385.9401 (f) Always working for a safer and healthier community
(f) 360-379-4487
within the Hood Canal watershed for the noxious weed known as knotweed, a Washington
State Noxious Weed (WAC 16-750). These plants are non-native, aggressive invasives, but
have the potential to be eradicated or adequately controlled within Washington. Knotweed is
of particular concern to salmon ecologists because of its ability to smother native species
which impacts biodiversity, water use, and native plants. It creates bank erosion problems
and lowers the overall quality of riparian habitat for fish and wildlife. If left untreated,
knotweed overwhelms and eventually displaces native vegetation. The HCSEG uses the
herbicide Glyphosate at the recommended dosage guidelines to control knotweed.
As part of its project, HCSEG also surveys the outcome of its knotweed treatments on
County -owned parcels and will, by separate agreement, replant those areas freed of this
invasive plant, also at no charge.
FISCAL IMPACT:
There is no impact to the General Fund for this agreement. Funding will be provided through
a grant to the HCSEG from the SRFB and WSDA.
JCPH management requests approval of the Permission to Enter and Waiver of Liability
Agreement for Knotweed Control with Hood Canal Salmon Enhancement Group for
Knotweed Control; January 1, 2016 — December 31, 2017; $0
REVIEWED BY:
,Philip Mora6_Administfor
°sT X5_
Date
Knotweed (Polygonum spp.) is a Class B Noxious Weed known to adversely affect riparian habitat by
multiple mechanisms such as reducing the amount of light available, altering river hydrology,
decreasing streambank stability and reducing food production. Knotweed forms dense thickets that
exclude native plant species and are of little value to wildlife due to the relatively low nutrient content
of its leaves and stems. Stream productivity declines as a result of this with fewer insects available to
salmon fry, for example.'
The Hood Canal Salmon Enhancement Group (HCSEG) requests permission to survey, control and
monitor knotweed on properties owned by Jefferson County as part of a multi-year effort to rid this
plant from the Big Quilcene and Dosewallips floodplains. Work will be conducted consistent with the
Hood Canal Knotweed Control Strategy and the recommendations of the Jefferson County Weed
Control Board and WSU Extension.
A comprehensive approach to the control and eradication of knotweed is necessary to reduce the risk
of infestation or re -infestation. The Weed Control Board Fact Sheet for knotweed states, "Because of
knotweed's tremendous ability to resprout following cutting, successful control usually requires
herbicides." The only recognized alternative to the use of herbicides involves locating and cutting
back the stems to the ground every two weeks for up to several years, which is cost -prohibitive.
The herbicide Aqua Neat ® (6%) and the surfactant LiberateTM (1.5%) will be applied together as a
foliar spray to the knotweed plants. This technique is preferred over another proven method —
injection of every knotweed stem with a very high concentration of herbicide — because it is less time
consuming and requires only a fraction of the total amount of herbicide used. The affected properties
will be signed as required to inform the public.
The following materials, in addition to the agreement, are included with this request:
1. Jefferson County Noxious Weed Control Board Fact Sheet for Knotweed
2. Hood Canal Regional Knotweed Control Strategy
3. List of knotweed references and excerpts
4. 2014-15 Jefferson County Agreement with HCSEG
5. List of parcels treated in 2015
Hood Canal Regional Knotweed Control Strategy can be found in public (\\courthouse) (V:) drive
' Hood Canal Regional Knotweed Control Strategy
Contract Number: K776
Permission to Enter Private Land and Waiver of Liability
Hood Canal Salmon Enhancement Group
Knotweed Control Project
January 1, 2016 to December 31, 2017
PERMISSION TO ENTER PRIVATE LAND AND WAIVER OF LIABILITY
THIS AGREEMENT INCLUDES PERMISSION TO ENTER PRIVATE PROPERTY AND A WAIVER
OF CERTAIN CLAIMS OF LIABILITY. READ CAREFULLY BEFORE SIGNING.
This Peralission to Enter Private ],and and Waiver of Liability is made between Hood Canal Salmon
Enliancenient ch-oup and JEFFERSON COUNTN hereafter referred to individually or collectively as "the
property owner(s)."
INTRODUCTION
1. The control and eradication of noxious weeds oil public and private lands is in the public interest and the
presence of knotweed (Poll o
g. ntun spp.) on private lands threatens wildlife habitat and provides a source
)
for renewed infestation of public lands. Effective eradication of knotweed requires concerted efforts on
both public and private lands to protect public resources.
2. Flood Canal Salmon Enhancenlent ciroup and its agents desire to assist other private landowners by
performing activities to eradicate all(]/(,),[- control knotweed on public and private lands within western
Washington. These activities are consistent with and supportive of duties imposed under statute.
3. The property owner(s) is/are the sole owner of property located at "SEX A.'41,'�TACHED ADDENDUM"
in Jefferson County, Washington hereafter referred to as "the property."
4. The property owner(s) is/are interested in and benefited by the eradication and/or control of knotweed on
the property.
5. The property owner(s) and Hood Canal Salmon Enhancement Group desire to memorialize an agreement for
the purpose of eradication and/or control of knotweed on the property.
AGREEMENT
1. Permission. In consideration of the benefits described above, the property owner(s) grant permission to
Hood Canal Salmon Enhancement Group and its agents, Contractors, cooperators and employees to enter
onto the property, from January 1, 2016, to December 31, 2017, to perform, activities to eradicate and/or
control knotweed on the property. The property owner( ' s) acknowledge and agree that these activities
may include the application of herbicide to the property, All I.,iroperdes will be accessed by/through the
river unless otherwise agreed to by property owner(s). Knotweed survey and control trealn-lents will only
occur along the river's edge/high-water mark, where knotweed is typically found.
The property owner(s) also grant permission to llgellts, Coll t I*acto rs, cooperators and employees of' the
Washington State Department of Agriculture to enter onto the property, froin January 1, 20,16, througli
December 31, 2017, for the purpose of monitoring and eval'uating tile success of knotweed cradication
and/or control activities. Property access will only be conducted by/through tile "k,'er unless otherwise
agreed to by property owner(s).
PERMISSION TO ENTER PRIVATE LAND Page 1 of 2
AND WAIVER OF LIABILITY REVISED 4/9/2014
Contract Number: K776
2. Ex iration and Revocation. Hood Canal Salmon Enhancement Group and its agents, contractors,
cooperators and employees are permitted to enter the property on all of the above dates and until
December 31, 2017, or until this permission is revoked, whichever occurs first. The property owner(s)
may revoke this permission by presenting a written letter of revocation to Hood Canal Salmon Enhancement
Group. The revocation is effective five (5) business days after receipt by Hood Canal Salmon Enhancement
Group.
3. Liability Waiver. The purpose of entry onto the property is to perform activities to eradicate and/or
control knotweed. The property owner(s) expressly agree to hold harmless Hood Canal Salmon
Enhancement Group, the Washington Department of Agriculture (WSDA), and the agents, contractors,
cooperators and employees of Hood Canal Salmon Enhancement Group, or WSDA, and to waive any claim
of liability against Hood Canal Salmon Enhancement Group, WSDA, and the agents, contractors,
cooperators and employees of Hood Canal Salmon Enhancement Group, or WSDA, for any injury, damage,
or harm which is the logical and intended consequence of activities properly performed to eradicate
and/or control knotweed.
The Hood Canal Salmon Enhancement Group and its agents, contnactors, cooperators and employees agree
to waive any claim of liability against the landowner for any injury, dainage, or harm which is not the
consequence of the landowner's negligence. As to any other act or omission of either party under this
agreement, each party shall be responsible for its own acts or omissions and those of its officers,
employees and agents under this agreement. No party to this agreement shall be responsible to the other
for the acts or omissions of entities or individuals not a party to this agreement.
4. Entire A =reement. This Permission to Enter Private Land and Waiver of Liability contains the entire
agreement between the parties with regard to the matters set forth herein.
5. Applicable Law. This Permission to Enter Private Land and Waiver of Liability shall be construed and
interpreted according to the laws of the State of Washington.
BY THE SIGNATURE BELOW, THE PROPERTY OWNER(S) DECLARE THAT THE TERMS OF THIS
PERMISSION TO ENTER PRIVATE LAND AND WAIVER OF LIABILITY HAVE BEEN
COMPLETELY READ AND FULLY UNDERSTOOD AND VOLUNTARILY ACCEPTED AND
EXPRESSLY WAIVE ANY CLAIM THAT THIS PERMISSION TO ENTER PRIVATE LAND AND
WAIVER OF LIABILITY IS NOT FAIRLY AND KNOWINGLY MADE.
Property Owner(s) Phone Number:
Property Owner(s) Address:
Street
Name of property owner
Name of property owner
Name of authorized representative,
Hood Canal Salmon Enhancement Group
City County
Signature of property owner
Signature of property owner
Signature of authorized representative,
Hood Canal Salmon Enhancement Group
only
Contact information for Hood 1.1 ah I "Ahancem . I G .C -p;
�e c n Ccs. bras t 1r"s i
PERMISSION TO ENTER PRIVA qTfDlvarez, Chief Civil DPA
AND WAIVER OF LIABILITY
PO Box 2169
Belfair, WA 98528
Zip
Date
Date
Date
360-275-3575
Page 2 of 2
REVISED 4/9/2014
Contract Number: K776
Addendum
Permission to enter Property and Waiver of Liability
Hood Canal Salmon Enhancement Group
Knotweed Control Project- January 1, 2016- December 31, 2017
The agreement grants permission to the Washington Department of Agriculture
to access the properties for the purpose of monitoring the success of the
eradication efforts.
BlQuilcene River:_
702234002, 991200202, 991200204, 991200205, 991200601, 991200609, 991201102,
991201401,991201402,991201403,991201405,991201903,991202105
Dr�eWalNi as Riven;
602342001, 602343001, 602343010, 602343012, 602343013, 602343014, 602344014,
602344022, 966900034, 966900035, 966900036, 966900046, 966900231
PERMISSION TO ENTER PROPERTY
AND WAIVER OF LIABILITY
Jefferson County Parcels Treated for Knotweed in 2015*
Water (gallons) + AquaNeat (ounces) + Liberate (ounces).
i�og C�uilce��e i�Nv�rw
000000250 (4 gallons- 30.8 oz. AquaNeat & 6 oz. Liberate)
991201402 (1.5 gallons- 11.6 oz. AquaNeat & 2.3 oz. Liberate)
991201403 (1.5 gallons- 11.6 oz. AquaNeat & 2.3 oz. Liberate)
991201405 (1.5 gallons- 11.6 oz. AquaNeat & 2.3 oz. Liberate)
991201903 (1.5 gallons- 11.6 oz. AquaNeat & 2.3 oz. Liberate)
991202105 (1 gallon- 7.7 oz. of AquaNeat & 1.5 oz. Liberate)
D_o s e w,River
602342001(0.5 gallons- 3.9 oz. AquaNeat & 0.75 oz. Liberate)
602343001 (0.5 gallons- 3.9 oz. AquaNeat & 0.75 oz. Liberate)
602344014 (1 gallon- 7.7 oz. of AquaNeat & 1.5 oz. Liberate)
602344022 (0.25 gallon- 1.9 oz. AquaNeat & 0.4 oz. Liberate)
*Not all parcels required chemical treatment during the 2015 season, however we would like to
still have the ability to survey and treat if necessary in the future. It is possible that we may have
overlooked some during our survey/treatment season. This is why I listed all parcels that were
in our previous agreements' addendum in this new consent agreement.
y LON (,, JEFFERSON COUNTY NOXIOUS WEED CONTROL BOARD
FACT SHEET
N r
KNOW EELS
Japanese knotweed( Polygonum cuspidatum); Giant knotweed (P.
sachalinense); Bohemian knotweed, (P. bohemicum) and Himalayan
knotweed (P. polystachyum)
• Thick green to reddish stems that look similar
to bamboo
• Large bright green leaves ranging from egg to
heart -shaped with a pointed tip
• Sprouts in April, grows to 15 feet tall or more
by July
• Spikes of white flowers appear from July to
September
• Giant and Japanese knotweed are
distinguished from each other primarily by the
size of the leaf and height of the plant—giant
being much larger with leaves up to 18 inches
long. Bohemian is intermediate between the
two and Himalayan knotweed (which has not
been seen in Jefferson County) has a much
narrower leaf
• Buckwheat family
ECOLOGY:
• Knotweeds generally spread by rhizomes
(underground stems which can sprout), but
sometimes by seed.
• Japanese and giant knotweeds frequently
hybridize, producing Bohemian knotweed.
Most of the knotweed in Jefferson County is
currently believed to be Bohemian.
DISTRIBUTION:
Knotweed is frequently seen in ornamental
plantings and on waterways.
The most affected waterways are the Big
Quilcene and Dosewallips Rivers
WHY BE CONCERNED?
Knotweed is extremely invasive and develops
a deep„ matted root system, with rhizomes that
can grow to 30 feet or more in length.
Originally, introduced as an ornamental, plants
frequently spread accidentally when roots or
stem pieces are moved by people, machinery
or water. Tiny root fragments as small as 1
inch can produce new plants.
Knotweeds form dense thickets that exclude
native species and are of little value to wildlife.
At the end of the growing season, a mass of
dead stems remains that crowds out native
plant seedlings and leaves river banks
vulnerable to erosion as well as to flooding.
Once established these plants are very difficult
to eradicate.
Knotweed is Class B Noxious Weed
Control is required in and within 50 feet of
gravel pits in Jefferson County.
380 Jefferson Street, Port Townsend WA 98368
360 379-5610 Ext. 205
noxiousweeds@co.jefferson.wa.us
http://www. co.jefferson.wa. us/WeedBoard
CONTROL
Prevention and early detection are the best means of control!
➢ Do not buy or plant invasive knotweeds
➢ Avoid introducing soil or gravel from areas known to have knotweeds
➢ Clean equipment that has been used in infested areas.
➢ Manually pull or dig small, poorly established infestations, removing ALL the roots.
➢ Dispose of weeds properly; do NOT leave stems or root fragments on moist ground or in
compost, because they will regrow. Also, never throw any part of knotweed plants into a
waterway, because they will be carried downstream and probably start a new infestation.
➢ Monitor the site for several years; promptly remove new plants, being sure to dig out all the
roots.
Because of knotweed's tremendous ability to resprout following cutting, successful control
usually requires herbicides.
SPRAY HERBICIDE on the leaves and stems in summer or early fall. To avoid spraying very
tall plants, it is possible to cut the stems once in May or June and allow the plant to regrow to
at least waist height. Most patches require more than one year of treatment.
NON -SPRAY HERBICIDE METHODS include injecting undiluted herbicide directly into the
lower sections of every stem or applying slightly diluted herbicide directly onto stems. Some
limitations, as indicated on the label, apply.
Always read and follow directions on the product label! Call the Weed Board for
specific herbicide advice.
Warning: Knotweed usually grows close to water and any herbicide application near or over
water requires a permit from the Department of Ecology and a specially licensed applicator.
MANUALLY PULL or DIG very small, poorly established infestations, removing all the
roots. Check often for new sprouts and repeat. Or, CUT the stems close to the ground every
two weeks throughout the growing season. Both methods will require several years of
persistent treatment for successful control. Manual methods should be used cautiously—
pulling or digging often leave root fragments in the ground --cutting or snowing do not remove
roots, and all methods can cause roots to resprout, often at some distance away. Be sure to
monitor up to 30 feet from the original plant, because shoots can arise that far away. Plant
parts should be disposed of carefully—see box above.
Jefferson County Noxious Weed Control Board has been successfully treating knotweed
infestations for several -years; -through the OLYMPIC--KNOTWEED- I - - - ,- -
will continue doing so. If you have knotweed on your property and
it is near water, please contact us.
Young knotweed sprouts can easily grow through asphalt!
380 Jefferson Street, Port Townsend WA 98368
360 379-5610 Ext. 205
noxiousweeds@co.jefferson.wa.us
hftp://www.co.jefferson.wa.usANeedBoard
List of Knotweed References and Excerpts
1) Community and ecosystem consequences of giant knotweed (Polygonum
sachalinense) invasion into riparian forests of western Washington, USA
Lauren S. Urgensona, b, , , Sarah H. Reichardb, Charles B. Halperna
http://www.sciencedirect.com/science/article/pii/S0006320709000998
"Where knotweed was present .... Litter mass of native species was reduced by 70%. Carbon:nitrogen ratio
of knotweed litter was 52:1, a value 38-58% higher than that of native woody species (red alder [Alnus rubra]
and willow [solix spp.]). Resorption of foliar N prior to leaf drop was 76% in knotweed but only 5-33% among
native woody species. By displacing native species and reducing nutrient quality of litter inputs, knotweed
invasion has the potential to cause long-terrra changes in the structure and functioning of riparian forests and
adjacent aquatic habitats"
"However, invaders can also have strong effects when they dominate ecosystem processes sa,ach as resource
acquisition or litter production (Reinhart et al,, 2006). These species have the potential to establish dense,
rnonotypic stands that monopolize resources and displace native species (Mack et al., 2000 and dukes and
Mooney, 2004).resulting in Voss of critical structures and functions from these systems (Hooper and Vitousek,
1997 and Chapin et al., 2000)."
"The ecological effects of invasion can be significant when non -natives displace foundation species—common
or abundant species that dominate community structure and moderate or stabilize fundamental ecosystem
processes (Ellison et al., 2005). Empirical evidence suggests that loss of foundation species can have
cascading effects (Jenkins et al., 1999 and Ellison et al., 2005)."
"Coniferous trees provide a key ecological function in the riparian none by contributing large woody debris
(LWd) to the active streamchannel and floodplain. LWD tends to be larger and slower to decay in coniferous
than in broadleaved species, thus it has greater longevity and functional significance (Fetherston rat al,, 1995).
LWd in streams plays an important role in routing of water and sediments and in shaping channel morphology,
factors that influence habitat quality for aquatic organisms (Abbe and Montgomery, 1996). "
"In addition to its effects on vegetation structure, replacement of native woody species by knotweed may
cha«arage the quality of litter, with important consequences for nutrient cycling and related processes in riparian
systems, Although quantity of litterf'aU did not duffer between invaded and non -invaded sites, nutrient quality did,
reflecting a significant reduction in the contribution of native woody species. In knotweed, resorption of >750% of
foliar nitrogen suggests that Most N is transported to rhizomes for storage (and subsequent use) before leaf
fall. In contrast, lower resorption in native species (only 5% in N -fixing red alder) results in the transfer of a
greater proportion of foliar N to riparian soils and aquatic environments."
"Changes in the composition and quality of riparian IitterfW may have additional effects that extend to aquatic
food -webs, Leaf litter from streamsido vegetation comprises a primary source of organic matter in forested
streams and backwater channels (Cummins et al,, 1973 and Wallace rat al,, 1 997) titter quality (C:N) affects
feeding preference, survivorship, growth rate, and fecundity of litter -feeding (shredding) aquatic macro -
invertebrates (Quinn et al., 2000 and Graga, 2001). "
2) Exotic invasive knotweeds (Fallopia spp.) negatively affect native plant and
invertebrate assemblages in European riparian habitats
Esther Gerbera, Christine Krebsa, , Craig Murrella, , Marco Morettib, , Remy Rocklinc, ,
Urs Schaffnera
http://www. scienced i rect.com/science/article/pi i/S0006320707004582
"Our findings suggest that riparian habitats invaded by knotweeds support lower numbers of plant species and
lower overall abundance and morphospecies richness of invertebrates, compared to native grassland -
dominated and bush -dominated habitats."
3) Impacts of invasive riparian knotweed on litter decomposition, aquatic fungi, and
macroinvertebrates
Shannon M. Claeson , Carri J. LeRoy, Jacob R. Barry, Kevin A. Kuehn
http://www.fs.fed. us/pnw/lwm/aem/docs/claeson/2013_claeson_et_al_knotweed_impacts_onlinefirst_112513. pdf
"Allochthonous organic matter inputs from riparian plants are an important source of energy and nutrients for
organisms in small streams. However, little information exists concerning the influence of knotweed on stream
processes. This study examines the quality of Bohemian knotweed leaves compared to native red alder and
black cottonwood leaves, along with leaf -associated fungal biomass acca. niulation, macroinvertebrate
com tTj urii ties, and decay rates from three forested streams in western Washington State. Senesced knotweed
leaves were lower in nitrogen and phosphorus, and higher in cellulose, fiber, and lignin content than alder
leaves, but were more similar to cottonwood leaves."
*This study is of personal significance, I assisted with the research during an internship for the lead
scientist....
4) The Ecological Consequences of Japanese Knotweed Invasion Into Riparian
Forests
Lauren Samantha Urgenson
http://www.cfr.washington.edu/research,cesu/reports/J9W88030027-Urgenson-MSThesis.pdf
Sturj!es�rRk �ndie q n��ivme cod�elatig1 betwt,er� lar gtwecrl Aovasa w anrlmtt1c s �js �i hne s ani
b rzel nc ,mof natty truwder`st r 1 erk� s ho,ubs p i uv_f?, 11e_LnpLe re jj tioa� m rjpgri n e estak 11 hment
_ 9. ' tl e wccessa � al !t�Ctor o- w ip r� ac mf r�er its, In nk taI imVr::"
detrimental
poadinrd la. i _» Y addition to
un ,effect oG� m
the displacement of native vegetation, a etation,� data suggest that knotweed Invasion alters istre a �t
p "" g gg am nutrient subsidies
from riparian litterfall. Results demonstrate an average 70% reduction of native litter inputs correlated with
knotweed invasion. Additionally, the C:N of senesced knotweed leaves is 52:1, a value 38% (Salix) to 58% (A.
rubra) higher than dominant native riparian species. Analysis of nutrient re -absorbance from senescing leaves
reveals that knotweed reabsorbs 75.5% of its foliar nitrogen prior to litterfall. In contrast, native species
reabsorb 2.3% (A. rubra) to 33% (Salix), thus contributing a greater proportion of their nitrogen resources to
riparian soils and aquatic environments through leaf litter. Litterfall from riparian vegetation comprise a primary
d energyin forested streams and backwater channels 11 I!tgejc the c,�rjo ir�K n arici.
source of nutrients and hthoar litter knotweed i0 a:sioa orals ®pi��ve �,det��d���rutal arro�_p u�tmmor+ t9ie- a� ��y
jLut�it[onal v;plue of al
of aqr� atnc tgod eb "
Does Stem Injection of Glyphosate Controlinvasive Knotweeds (Polygonum spp.)? A Comparison of
Four Methods
Erin N.Hagen and Peter VKDunwiddio^
"For example, foliar application ofglyphosate iowidely used auacontrol method and can reduce knobwoed
ahame by7Oho 901/10 over (SoU et aL 2807). Hmwmver, there are several limitations hnthis approach. It often
takes several years to achieve complete patch mortality using foliar applications, and the application method is
not suitable inall weather uondiUonn.^
"^ However, even our limited observations mug,geot that |ong-tern`,effective control o4knokweedmay not bu
practical it) many Situations with the injection tool. The lack of injury to noninjected knotweed sten,is, even those
very near injected stems, suggests that each stem must be treated in a stand to ensure effective control."