Skip to main content

Main menu

  • Home
  • Content
    • Ahead of Print
    • Current Issue
    • Special Issues
    • All Issues
  • Contribute
    • Submit to AUF
    • Author Guidelines
    • Reviewer Guidelines
  • About
    • Overview
    • Editorial Board
    • Journal Metrics
    • International Society of Arboriculture
  • More
    • Contact
    • Feedback
  • Alerts

User menu

  • Log in

Search

  • Advanced search
Arboriculture & Urban Forestry
  • Log in
Arboriculture & Urban Forestry

Advanced Search

  • Home
  • Content
    • Ahead of Print
    • Current Issue
    • Special Issues
    • All Issues
  • Contribute
    • Submit to AUF
    • Author Guidelines
    • Reviewer Guidelines
  • About
    • Overview
    • Editorial Board
    • Journal Metrics
    • International Society of Arboriculture
  • More
    • Contact
    • Feedback
  • Alerts
  • Facebook
  • Twitter
  • YouTube
  • LinkedIn
Research ArticleArticles

Herbicide Injury to Trees

John A. Meade
Arboriculture & Urban Forestry (AUF) September 1977, 3 (9) 167-168; DOI: https://doi.org/10.48044/jauf.1977.043
John A. Meade
Extension Specialist in Weed Science, Soils and Crops Department, Cook College-Rutgers University, New Brunswick, New Jersey
  • Find this author on Google Scholar
  • Search for this author on this site
  • Article
  • Info & Metrics
  • References
  • PDF
Loading

A herbicide is a chemical used to kill unwanted plants. Often these plants are growing in association with desirable plants. To kill one plant growing in close association with another is difficult and relies on the property of selectivity. This selectivity depends on several things, such as the herbicide, temperature, rainfall, and species of plant involved. When selectivity fails, we have tree injury.

Those herbicides generally involved in tree injury fall into two classes: 1) compounds used to kill broadleaf weeds in turf; and 2) total vegetation control agents.

The first group causes injury in three ways:

Drift

Listen

Movement of spray particles through the air. These particles contact the leaves of desirable plants and injury results. This, of course, shows up only during the growing season. Conifers are more resistant that deciduous plants.

Volatility

Listen

These compounds are usually used when air temperatures are high (60-85 deg. F). At elevated temperatures, some formulations will evaporate into a gas. This gas then moves through the air to contact desirable plants. The herbicide is absorbed and injury occurs.

Root absorption

Listen

While the life of these compounds in soil is short (2-3 weeks) and they do not penetrate deep into the soil (1-4”), tree roots can intercept some of these compounds and move them up into the tree where injury symptoms show up.

The second group causes injury usually by root absorption. These herbicides are designed to be long-lived in the soil and indeed some persist for a year or more. Since they are there longer, they move deeper into the soil with rainfall. Hence, they have more chance of coming into contact with tree roots.

Appearance of Injury symptoms

Listen

Herbicides in the first group, 2,4-D, 2,4,5-T, silvex, MCPP (Mecoprop), Banvel, and Tordon, all affect plants in a similar fashion. They generally move from the point of contact to the growing points. Hence, injury symptoms most often show up in young leaves first. These compounds cause malformation of the leaves and petioles. The edge of the leaf may curl up to form a cup or it may curve downward. If the leaf has points on it, these points become elongated and often look like strings. The petiole quite often will curl also. With some species, the leaves assume a “strap” shape, long, and narrow.

The total vegetation control materials generally enter trees through the root system, either because the tree roots were growing into the treated area or because the herbicide had washed across the surface of the soil and then penetrated into the root zone. Incidentally, once herbicides have moved downward into the soil, they do not move sideways to any significant degree. One of the problems in using these herbicides is trying to determine how far tree and shrub roots grow out away from the trunk. This varies considerably with the species and soils.

These materials, such as Hyvar, Pramitol, Urox, Spike, Telvar, and various other trade names, enter the root system and move up into the tree. The injury symptoms are manifested first at the edge or tip of the leaf and then generally move back to the base. The leaf first turns yellow and then brown. Hyvar sometimes blackens the leaf. Depending on the dosage, the tree defoliates the year of treatment and then refoliates. The second year, the tree will put out weak foliage and then death occurs.

Treatment and prognosis

Listen

Trees quite often recover from exposure to the first group. The leaves will be misshapen and will often drop, but depending on species and dosage will appear normal in two years or so. However, death can occur if the dose is high. There is no specific treatment to alleviate the injury symptoms. Pruning the branches will often help the appearance of the tree. It would probably be best not to fertilize the trees although additional water would be helpful. Don’t be in too much of a hurry to remove the tree the first year since they can make surprising comebacks from the action of these herbicides.

Trees reacting to exposure to the second group of herbicides, however, have shown a smaller rate of recovery. Once again, after the material is in the tree, there is little that can be done to aid the tree. Pruning is of little value since the materials are distributed throughout the tree. It would be best to wait for a year or two to see if the tree comes back. If it does not put out foliage the year after exposure, it can be assumed that it is dead and should be removed.

Where did the herbicide come from?

Listen

One must be a detective sometimes to trace down the source of herbicide injury. Quite often the person doing the application is not aware that he is using a compound which hurts trees. Don’t accept the statement, “I’m not using anything which hurts trees.” Ask (diplomatically) to see the container and check the ingredients statement. If it’s unfamiliar, copy it down and check with your county agent. If the injury is typical of group 2, look uphill to see if perhaps the chemical was carried by rainwater run-off.

Some sources of injurious herbicides are municipal and state highway departments, homeowners, power line clearance crews, railroad, and electric substations.

It is also beneficial to check the area around the injured tree to see if the weeds are curled up or if other trees or shrubs in the area are injured.

Don’t forget that plants can grow and change color in only so many ways and other things can cause injury similar to herbicide injury symptoms.

Footnotes

Listen
  • ↵1 Paper presented to National Arborists Assn. Seminar on pollution damage to trees, December 8-9, 1976, East Brunswick, New Jersey.

  • © 1977, International Society of Arboriculture. All rights reserved.

References

Listen
  1. 1.
    1. Meade, John A.
    1975. Street trees and herbicides. Journal of Arboriculture 1:
    1. Meade, John A.
    1975. Precautions in choosing herbicides. Proceedings Annual Meeting, New Jersey Federation Shade Tree Commissions.
PreviousNext
Back to top

In this issue

Arboriculture & Urban Forestry (AUF)
Vol. 3, Issue 9
September 1977
  • Table of Contents
  • Index by author
Print
Download PDF
Email Article

Thank you for your interest in spreading the word on Arboriculture & Urban Forestry.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Herbicide Injury to Trees
(Your Name) has sent you a message from Arboriculture & Urban Forestry
(Your Name) thought you would like to see the Arboriculture & Urban Forestry web site.
Citation Tools
Herbicide Injury to Trees
John A. Meade
Arboriculture & Urban Forestry (AUF) Sep 1977, 3 (9) 167-168; DOI: 10.48044/jauf.1977.043

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Share
Herbicide Injury to Trees
John A. Meade
Arboriculture & Urban Forestry (AUF) Sep 1977, 3 (9) 167-168; DOI: 10.48044/jauf.1977.043
del.icio.us logo Twitter logo Facebook logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One
Bookmark this article

Jump to section

  • Article
    • Drift
    • Volatility
    • Root absorption
    • Appearance of Injury symptoms
    • Treatment and prognosis
    • Where did the herbicide come from?
    • Footnotes
    • References
  • Info & Metrics
  • References
  • PDF

Related Articles

  • No related articles found.
  • Google Scholar

Cited By...

  • No citing articles found.
  • Google Scholar

More in this TOC Section

  • Contribution of Urban Trees to Ecosystem Services in Lisbon: A Comparative Study Between Gardens and Street Trees
  • Unmanned Aerial Vehicle (UAV) in Tree Risk Assessment (TRA): A Systematic Review
  • Thiabendazole as a Therapeutic Root Flare Injection for Beech Leaf Disease Management
Show more Articles

Similar Articles

© 2025 International Society of Arboriculture

Powered by HighWire