The Forest Board
has reviewed the recommendations on Emerald Ash Borer treatment over the past
two years and has reviewed the Park ashes with several experienced Certified
Arborists. The first 10 trees out of 30 were
treated in 2010 and 12 trees will be treated in 2013, with retreatment in 2015.
Effective
treatments for Emerald Ash Borer depend on size of the tree, and almost all of
the ashes in Audubon Park are substantial trees (larger than 6-8 inches in diameter
at 4.5 foot from the base of the tree).
Mature trees require injection by an experienced Certified Arborists and
Emamectin benzoate appears to be the most effective agent. All the people listed below are using Emamectin.
Treatment
currently costs about $10 per inch of diameter, so a tree of 30 inch DBH is
approximately $300 to treat. For early
prevention, treatment should occur in mid-May to mid-June, and can be stretched
to every three years. When we identify
an active epidemic in Audubon Park, it will be safer to treat at two year
intervals, and then resume three year treatments after most trees are removed
in our area. Recommendations are that
the tree be treated for its entire life-span.
In general,
you should not treat a damaged or compromised tree, particularly a tree with
major wounds or areas of visible or developing rot. Your arborist can evaluate whether the tree
is worth treating. If you do remove an
ash, please ask that it be inspected careful for whether EAB contributed to its
decline. Let the Forest Board know if
you identify EAB in your tree.
You are
making an investment in treating your tree, and it can difficult to assess and
weigh the costs of long-term treatment compared to the cost of removal of the
tree in the next few years. Sometimes it
will be better to remove the tree, and get replanting done. A certified competent up-to-date and
well-trained professional arborist can help you with this decision. You will be spending substantial amounts in
treating your tree, and make sure you choose an honest established provider. There are also many online resources that
look at the cost-benefit of various strategies.
But only you know the tree and the benefits it provides you and what it
is worth to retain it.
Several
experienced people already have been treating ashes with injection of Emamectin
benzoate in Audubon Park. For your
convenience, we have listed their companies and names, with contact
information. Many other reputable tree
companies have developed a Plant Health division in their company in
anticipation of the impact of EAB in Louisville. Please bring them to the attention of the
Forest Board so we can update the list of providers if you are satisfied with
their professional qualifications and work.
Some current providers of Emamectin benzoate injections
- Arbor
Worx, Joe Clayton, 502-491-1304; 502-817-3183.
- Natural
Resources and Property Management, LLC, Gregory Stephens, 502-896-6369; cell:
502- 435-2497, email: greg.stephens50@att.net.
- Limbwalker
Tree Services, Inc., 502-634-0400
| (The excerpt below is from “Insecticide Options for Protecting Ash Trees from Emerald Ash Borer” by Herms, McCullough, Smitley, Sadof, Williamson, and Nixon.) Trunk-Injected Systemic Insecticides Emamectin benzoate • In several intensive studies conducted by MSU and OSU researchers, a single injection of emamectin benzoate in mid-May or early June provided excellent control of EAB for at least two years, even under high pest pressure. For example, in a highly-replicated study conducted on trees ranging in size from 5-to 20-inch DBH at three sites in Michigan, untreated trees had an average of 68 to 132 EAB larvae per m2 of bark surface, which represents high pest pressure. In contrast, trees treated with emamectin benzoate had, on average, only 0.2 larvae per m2, a reduction of > 99 percent. When additional trees were felled and debarked two years after the emamectin benzoate injection, there were still virtually no larvae in the treated trees, while adjacent, untreated trees at the same sites had hundreds of larvae. In two OSU studies conducted in Toledo with street trees ranging in size from 15 to 25-inch DBH, a single application of emamectin benzoate also provided excellent control for two years. There was no sign of canopy decline in treated trees and very few emergence holes, while the canopies of adjacent, untreated trees exhibited severe decline and extremely high numbers of emergence holes. One study suggests that a single injection of emamectin benzoate may even control EAB for three years. Additional studies to further evaluate the long-term effectiveness of emamectin benzoate are underway. To date, this is the only product that controls EAB for more than one year with a single application. In addition, in side-by-side comparisons with other systemic products (neonicotinoids), emamectin benzoate was more effective. |
 Updating...
Ċ Anne Bobigian, Nov 29, 2012, 5:35 AM
Ċ Anne Bobigian, Nov 29, 2012, 5:38 AM
Ċ Anne Bobigian, Nov 29, 2012, 5:38 AM
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