Tree Injection Case Study

The Science of Matching the Tool to the Job

During our 40 years of Dutch elm disease experience we have evaluated every treatment option under the sun. Macro-injections, micro-injections, soil applied treatments, even bark sprays as well as a number of different fungicide formulations.

We have a 99.5% success rate preventing elms from infection by this disease. Understanding just a few key distinctions about the biology of the disease and the physiology of the tree helps explain why macro-injection and Arbotect® are the tools we use.

Micro-injection utilizes small volumes of water and fewer injection sites. Research has shown micro-injections to be very effective for insecticides, miticides, and antibiotics but not with fungicides for vascular wilts.

Macro-injection uses high volumes of water, allowing for even and complete coverage of the treatment throughout the canopy. This is critical for vascular wilts like Dutch elm disease.

Compare these conclusions with the recommendations provided by other tree injection device manufacturers.



In the case of preventative treatments for Dutch elm disease, it is vital that every single twig in the canopy receives an ample amount of the treatment. This is because the elm bark beetles that spread the deadly fungus are feeding in the 2-3 year old branches at the very top of the tree. Missing even a small percent of those branches greatly increases the tree's chance of infection.

CONCLUSION: Only Macro-Injection provides enough solution to effectively cover the entire canopy.


Fungicides do not exhibit much lateral movement inside the xylem; the treatments go fairly straight up. Getting even and complete distribution is critical for successfully protecting the tree.

Micro-injection vs Macro-injection

CONCLUSION: Only a higher number of injection sites applied with even pressure can ensure complete canopy coverage.

Micro-injection vs Macro-injection - products


Protection from this deadly disease is a lifelong commitment for the tree, thus it is imperative that the tree have enough time between treatment to compartmentalize the injection wounds. Research shows Arbotect® moves into new xylem tissue, protecting new twigs for up to 3 years. Propiconazole lasts in the tree just 8 months and does not move into new tissue. CONCLUSION: Only Arbotect® will protect the tree for multiple seasons, allowing enough time to compartmentalize the wounds from previous treatments

Cost of Treatment Options for Dutch Elm Disease Protection

WHAT ARE THE COSTS OF AN ANNUAL TREATMENT OR A 3-SEASON TREATMENT OVER TIME? Scientific research has shown two treatments are effective for protecting elm trees from Dutch elm disease. This research shows that one treatment, Arbotect®, is effective for 2.5-3 seasons of protection, whereas the other treatment, Alamo, is effective for just one season. Both of these treatments are applied by Macro-Infusion, a process where a large volume of solution is injected into the tree by drilling a series of holes into the root flares. Let’s compare how the costs of the service and the impacts on the tree add up over time:


Everything we recommend starts with a protocol that includes proper diagnosis and the full suite of management options. You can check out our library of treatment guides.