A review of literature and field practices focused on ... - Invasive.org
A review of literature and field practices focused on ... - Invasive.org
A review of literature and field practices focused on ... - Invasive.org
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Well-established knotweed is difficult to eradicate. Depending <strong>on</strong> the c<strong>on</strong>trol strategy<br />
used <str<strong>on</strong>g>and</str<strong>on</strong>g> the vigor <str<strong>on</strong>g>of</str<strong>on</strong>g> the plants, successful c<strong>on</strong>trol may entail managing a particular<br />
st<str<strong>on</strong>g>and</str<strong>on</strong>g> for several years <str<strong>on</strong>g>of</str<strong>on</strong>g> m<strong>on</strong>itoring <str<strong>on</strong>g>and</str<strong>on</strong>g> repeated applicati<strong>on</strong>s. Manual <str<strong>on</strong>g>and</str<strong>on</strong>g> mechanical<br />
c<strong>on</strong>trols will in nearly all cases require more site visits <str<strong>on</strong>g>and</str<strong>on</strong>g> c<strong>on</strong>trol effort than will<br />
herbicide-based c<strong>on</strong>trols. For example, mowing is recommended to repeated every 2<br />
weeks during the growing seas<strong>on</strong> <str<strong>on</strong>g>and</str<strong>on</strong>g> probably will not result in eradicati<strong>on</strong> (Talmage &<br />
Kiviat, 2004) whereas herbicide applicati<strong>on</strong> through stem injecti<strong>on</strong> followed by a foliar<br />
spray <str<strong>on</strong>g>of</str<strong>on</strong>g> sprouts in the next growing seas<strong>on</strong> can result in eradicati<strong>on</strong> (Phil Burgess,<br />
Director, Clark County Weed Management, Washingt<strong>on</strong>, pers<strong>on</strong>al communicati<strong>on</strong>).<br />
Even with the use <str<strong>on</strong>g>of</str<strong>on</strong>g> herbicide, knotweed has been found to be very difficult to eradicate<br />
in some circumstances. Practiti<strong>on</strong>ers have observed wide ranging results in c<strong>on</strong>trol <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
different knotweed st<str<strong>on</strong>g>and</str<strong>on</strong>g>s using the same c<strong>on</strong>trol methods (Steven Flint, <strong>Invasive</strong> Field<br />
Steward, Adir<strong>on</strong>dack TNC, pers<strong>on</strong>al communicati<strong>on</strong>; Tim Miller, Extensi<strong>on</strong> Weed<br />
Specialist, Washingt<strong>on</strong> State University, pers<strong>on</strong>al communicati<strong>on</strong>). The best approach<br />
may be to use a variety <str<strong>on</strong>g>of</str<strong>on</strong>g> methods, manual <str<strong>on</strong>g>and</str<strong>on</strong>g>/or chemical. For example, <strong>on</strong>e c<strong>on</strong>trol<br />
recommendati<strong>on</strong> is to cut knotweed stems in the spring <str<strong>on</strong>g>and</str<strong>on</strong>g> apply a foliar spray to the<br />
sprouts during the early fall in the same year. This is an example <str<strong>on</strong>g>of</str<strong>on</strong>g> Integrated<br />
Vegetati<strong>on</strong> Management (IVM) (Gover, 2005).<br />
C<strong>on</strong>trol Methodology Summary(from Soll 2004)<br />
So you have knotweed <str<strong>on</strong>g>and</str<strong>on</strong>g> want to be rid <str<strong>on</strong>g>of</str<strong>on</strong>g> it? Good. It is possible, but not usually easy,<br />
especially at a l<str<strong>on</strong>g>and</str<strong>on</strong>g>scape scale. Because <str<strong>on</strong>g>of</str<strong>on</strong>g> knotweed’s incredibly extensive root system<br />
<str<strong>on</strong>g>and</str<strong>on</strong>g> sprouting ability, l<str<strong>on</strong>g>and</str<strong>on</strong>g>scape level c<strong>on</strong>trol must be thought <str<strong>on</strong>g>of</str<strong>on</strong>g> within the c<strong>on</strong>text <str<strong>on</strong>g>of</str<strong>on</strong>g> a<br />
program. Even <strong>on</strong> a patch by patch basis, successful eradicati<strong>on</strong> is likely to take more<br />
than <strong>on</strong>e year, let al<strong>on</strong>e <strong>on</strong>e treatment in most cases. Finally, although there are<br />
potentially successful mechanical or manual c<strong>on</strong>trol opti<strong>on</strong>s for small patches, l<str<strong>on</strong>g>and</str<strong>on</strong>g>scape<br />
level projects <str<strong>on</strong>g>and</str<strong>on</strong>g> large sites will almost certainly require integrating herbicide use into a<br />
c<strong>on</strong>trol strategy.<br />
Although this document does not address it, a successful l<str<strong>on</strong>g>and</str<strong>on</strong>g>scape level program will<br />
almost certainly involve outreach to private l<str<strong>on</strong>g>and</str<strong>on</strong>g>owners <str<strong>on</strong>g>and</str<strong>on</strong>g> the broader community, as<br />
well as volunteer recruitment <str<strong>on</strong>g>and</str<strong>on</strong>g> coordinati<strong>on</strong>. You may need an outreach program to<br />
reach l<str<strong>on</strong>g>and</str<strong>on</strong>g>owners that may have knotweed <strong>on</strong> their property. You almost certainly will<br />
need to educate those property owners <str<strong>on</strong>g>and</str<strong>on</strong>g> others so that they fully realize the threat<br />
knotweed poses. Fully underst<str<strong>on</strong>g>and</str<strong>on</strong>g>ing the devastating effects that knotweed can have <strong>on</strong><br />
waterways <str<strong>on</strong>g>and</str<strong>on</strong>g> riparian ecological systems can <strong>on</strong>ly help motivate people to act.<br />
You may also want to work with volunteers <str<strong>on</strong>g>and</str<strong>on</strong>g> other <strong>org</strong>anizati<strong>on</strong>s in your community<br />
to exp<str<strong>on</strong>g>and</str<strong>on</strong>g> your ability to physically get the work d<strong>on</strong>e. Helping to create <str<strong>on</strong>g>and</str<strong>on</strong>g> protect free<br />
flowing waterways <str<strong>on</strong>g>and</str<strong>on</strong>g> noxious weed-free embankments provides the rewards that can<br />
inspire citizens to participate more fully in natural resource restorati<strong>on</strong> projects.<br />
Mechanical or Manual C<strong>on</strong>trol<br />
Variati<strong>on</strong>s: Cutting, mowing, pulling, digging, covering<br />
The goal <str<strong>on</strong>g>of</str<strong>on</strong>g> mechanical c<strong>on</strong>trol is to remove or starve the root system. In experiments<br />
c<strong>on</strong>ducted by The Nature C<strong>on</strong>servancy between June 2000 <str<strong>on</strong>g>and</str<strong>on</strong>g> June 2003 <str<strong>on</strong>g>and</str<strong>on</strong>g> as reported<br />
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