Protecting Ash Trees at Cornell Botanic Garden

On May 31st and June 1st, Arborjet | Ecologel donated Tree-äge G4 (4% emamectin benzoate) for the retreatment of ash trees being attacked by emerald ash borer (Agrilus planipennis), a part of our Saving America’s Iconic Trees Program.

Cornell has tens of thousands of ash trees across its campus and surrounding areas and has been working with Arborjet since 2018 in an effort to mitigate the damage from the highly invasive Emerald Ash Borer (EAB). The trees were treated using environmentally sound, trunk injection treatments to protect against EAB, a bright metallic green beetle that feeds on ash trees. A native of Asia, the insect has killed millions of trees in the U.S. and Canada since its discovery in 2002, and is regarded as one of the most destructive forest pests in North America.

Invited faculty, staff, and students attended and watched a demonstration of the treatment process to learn more about invasive species and diseases affecting the country’s urban forests, and the technology available to protect and save trees.

This is the third treatment in over five years to protect ash. Arborjet | Ecologel coordinated the retreatment program with Todd Bittner, Director of Natural Areas, Cornell Botanic Gardens.

Arborjet has been working with the Botanic Gardens for 14 years, first treating hemlock for Hemlock Woolly Adelgid (HWA), a non-native, piercing sucking insect that left untreated will kill trees.  Systemically applied imidacloprid (IMA-jet) was applied to protect the hemlock along the Cascadilla Gorge trail.

Arborjet returned in 2018 to treat over 50 ash trees, a key component to the woodlands overstory.

“We appreciate our partnership with Arborjet and the opportunity for students to learn from experienced, professional arborists about invasive species, while acquiring hands-on experience…” said Todd Bittner.

Cornell has successfully treated for EAB, providing the best defense against this invasive pest. Planning for the long term and treating trees before vascular damage, has proven to be a highly effective approach.

John Joseph Aiken, regional technical manager for the Great Lake States worked with and trained Mark Matthews, Natural Areas Steward treating ash in the natural areas.

Joe Doccola, Director of Research and Development, worked with Zaidee Powers Rosales, IPM Assistant Horticulturist in the F.R. Newman Arboretum, and with and trained Emma Gutierrez, Natural Areas Steward.

Systemic Tree Injection Process

The process of tree injection is a methodology designed to apply a protective treatment directly into the vascular tissues of the tree. This method has distinct advantages over spray and soil injection applications, which include limited environmental exposures, highly efficient use of chemistries, and residual activity.

The use of the Arborplug, a designed interface and backflow preventer protects the applicator and non-target organisms from chemical exposure. The Arborplug has three components which include infusion legs, anchoring barbs and guide cap. Internally a self-healing septum seals after the injection needle is removed. At injection, the injection needle applies the chemistry within the infusion leg channel. The liquid formulation is delivered directly to the vascular tissue for systemic movement. Applied correctly, the anchoring barbs fit into the sapwood, separating chemistry from the lateral cambium. The lateral cambium is comprised of vascular initials that after application, divide to create new tissues to close over the injection site.

The application process is simple: drill, plug and inject. Perhaps the most technical part of the application is setting the Arborplug properly. Using a cordless drill and high helical drill bit, first drill through the bark. Apply no pressure to the drill. It will naturally “land” at the sapwood, which is denser than the bark tissue. Remove the drill and you will have the countersink depth to fit and set the Arborplug properly. Next, reapply the drill using pressure to cut into the sapwood. Drill a minimum of 5/8” (the length of the Arborplug) in ash trees.

Locate the injection points into exposed roots or into the trunk flare tissues low in the tree.

Using a set tool, which is fitted onto the Arborplug guide cap, tap in using a hammer or mallet.  Feel for increasing resistance and a change in tonality. Inspect the Arborplug to be sure it is properly countersunk.

Next, insert the injection needle into the Arborplug, and make the application. That’s it! Except of course, application points are applied around the base of the tree, one point every 6” of tree circumference. This helps to insure adequate distribution of formulation into the canopy of the tree.

Arborjet | Ecologel has consistently funded university research and student scholarships in arboriculture, horticulture, entomology, and environmental science. Arborjet President and CEO Russ Davis adds, “We hope to inspire educators and students at Cornell and other colleges and universities across the country to encourage students to pursue a degree and ultimately a career in this important industry. Our goal through our Saving America’s Iconic Trees Program is to educate and to raise awareness across the tree care community to grow the industry, and to be strong stewards of the environment.”