• High Volume Macro Infusion

Arbotect 20-S® (active ingredient Thiabendazole 26.6%) is a tree injected systemic fungicide used for the prevention of Dutch elm disease and suppression of sycamore anthracnose. One application of Arbotect by macro-infusion protects the entire canopy for up to three growing seasons.  For more information on why Arbotect is a good choice for your tree, read our blog on the benefits of Arbotect.

Application Type(s)

High Volume Macro Infusion


Dutch Elm Disease: Applications can be made after leaves have fully enlarged, which coincides with seed drop in the spring. Treatments may continue through the growing season until fall color begins.

Sycamore Anthracnose: Applications can be made mid to late summer until to fall color begins. Do not treat sycamores with thin, partial canopies during the early part of the growing season.

More information is available in the Arbotect Product Guide.

Note: This product cannot be sold in the following states: AK, AZ, PR. Pesticide Applicators License Required in New York, not available in Canada. We apologize for any inconvenience this may cause.

Arbotect is available in the following sizes/variations.


1 gallon (1201)
Price: $562.17

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Not all products are available for sale in all states.  Make sure that any product you intend to purchase is registered for use in your state, and that you have all of the required licenses to apply the product purchased.  Any recommendations made by the tree geek website or its employees are based on limited knowledge of your area and are for informational purposes only.  Always seek advice from a local professional if you are not sure of your tree or pest identity.

Arbotect Dosage Rates

Dutch Elm Disease:

• Apply 2.4 fl. oz. of Arbotect 20-S per inch of trunk diameter.

• Dilute each fluid ounce of Arbotect 20-S with ½ gallon of water.

• Do not use this treatment if trees are less than 10″ DBH.

• Use half as much Arbotect (1.2 fl. oz. per inch of DBH) for all red elms.

Sycamore Anthracnose:

• Apply 1.6 fl. oz. of Arbotect per inch of trunk diameter.

• For trees >30 inches consider applying 2.4 fl. oz. per inch of trunk diameter.

• Dilute each 1 fl. oz. of Arbotect in ¼ gallon of water.

Dosage Reduction Considerations

Dutch Elm Disease

• Reduce the dosage rate by 50% for American elms less than 15 inches in diameter and all sizes of red elms.

Total DBH: 0 inches.
Estimated minimum total product needed (low rate): 0 oz
Estimated maximum total product needed (high rate): 0 oz

Based on the size of your trees, we estimated you will need ONE of the following options:

1 @ 1 gallon

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