What’s The Difference Between Glyphosate And Triclopyr?

There are a number of herbicides on the market that can be used for tree and plant growth control. Some of them include Grazon, Pathfinder, Garlon, Dicamba, Roundup, and Tordon. Glyphosate and Triclopyr are some of the most popular compounds that many of the mentioned products contain.

Both Glyphosate and Triclopyr are synthetic systemic herbicides. While glyphosate is broad-spectrum, triclopyr is effective on selective species. Although both the herbicides are not dangerous for humans, triclopyr happens to be slightly more toxic.

The Similarities Between Glyphosate and Triclopyr

Before we get to the differences between the two, let’s take a look at what the similarities are. Both Glyphosate and Triclopyr are synthetic, that is, they are man-made. The other similarity is how they work in targeted plants.

Both the herbicides are systemic in nature. This entails that once the chemical has been absorbed by the plant, it will be transported throughout the plant using the plant’s vascular system.

Differences Between Glyphosate and Triclopyr

  • The first difference between both the compounds is that while glyphosate is nonselective, triclopyr is selective. This means that glyphosate will kill or affect any species it comes in contact with. Triclopyr will only be effective on broad-leaf and woody plants and trees. As opposed to Glyphosate, Triclopyr rarely affects grass.
  • The other difference is the way they affect the targeted vegetation. While both the compounds are systemic, they affect different enzymes and chemicals within the targeted plant.
    Glyphosate is an organic, high phosphate compound, and it affects the protein production processes within a plant.
    Triclopyr works by mimicking an enzyme that is already present within the plant called auxin (indole acetic acid). Auxin is responsible for controlling the growth of plants and trees. By mimicking auxin, triclopyr causes unregulated and uncontrolled growth within a plant which leads to its death. Read more about the effects of Triclopyr in the linked post.
  • Both the compounds are not very toxic to humans, but triclopyr can have moderate levels of toxicity, especially through long-term exposure.
    Even though not classified as toxic, both compounds can affect eyesight or cause permanent damage if come in direct contact with the eyes.
  • Glyphosate can take up to 7-14 days to take effect on larger trees while triclopyr is slightly faster and can show results within 3-5 days.
 GlyphosateTriclopyr
EffectivenessBroad-spectrumSelective
EfficiencySlower (7-14 days on larger plants and trees)Faster (3-5 days on larger plants and trees)
Mode of AttackSystemicSystemic
ToxicityLowLow to Moderate
OriginsSyntheticSynthetic
Glyphosate vs Triclopyr

A Comparison Between Glyphosate and Triclopyr

Let’s take a look at a comparison between both the compounds and how they interact in different scenarios.

Application Process

The application process for both the herbicides is quite similar, the only caveat being that you will have to be very careful while handling glyphosate because of its broad-spectrum nature. Spraying or applying it carelessly will affect nearby vegetation as well.

Both the herbicides can be sprayed or applied to the foliage or the leaves of the target vegetation. They are then absorbed by the plant and transported throughout it.

For bigger plants, the recommended application method is through cut stump treatment, cut surface treatment or and basal bark treatment.

When to Use Glyphosate and Triclopyr?

While you can use both herbicides all year round, the preferred time to use them is when the plants and trees are going through active growth. During this time, the plants are taking in more nutrients which also increases the amount of herbicide they will absorb.

The best time to use them would be early to late spring and even late summer. If you are dealing with deciduous trees, the winter season would be the worst time for application.

What Vegetation Do They Target?

As stated above, glyphosate is a broad spectrum. This means that it will affect most trees, plants, and weeds including grass. It is most effective on broadleaf plants which entail large, flat, and broad surfaces.

Triclopyr on the other hand works on broadleaf plants and plants with woody stems. It is not effective on most grasses. Triclopyr is majorly used for controlling the growth of nettles, brambles, and plants near lawns or gardens.

Triclopyr is extremely effective on brooms which include Cytisus spp., Genista spp., Spartium spp.; gorses like Ulex spp.; fennel (Foenciulum bulgare). Triclopyr ester formulation is known to be effective on root or stem spouting species including buckthorns, ash, and black locusts.

Difference Between Their Effectivities

The first effects of glyphosate which include wilting, browning, and drying of leaves can be visible within 12-24 hours of application. Complete death of the plant and its roots can be visible within 7-14 days, but this might be longer with larger trees.

With triclopyr, wilting and yellowing of leaves can be seen within 48 hours of application but it will end up killing plants and weeds within 3-5 days. Again, this might take longer with larger trees. The ester variety of triclopyr can sometimes take longer to show results.

Which Herbicide is Safer?

Prolonged exposure to triclopyr to the skin can lead to allergic reactions. The compound has low vapor pressure which means that it is not that toxic through inhalation.

Triclopyr is classified as a class D chemical and it is not known to have any carcinogenic effects on humans. But the contact with this herbicide in the eyes can cause permanent damage.

Glyphosate is also not toxic to humans and neither of the chemicals does not bioaccumulate in animals.

Because of the potential for eye damage, triclopyr would technically be more dangerous to use.

Can You Mix Glyphosate and Triclopyr?

Yes, you can mix both the compounds together. It will result in a broad-spectrum herbicide. There are no studies that indicate a difference in effectiveness when both the compounds are mixed together.

Glyphosate is not that effective on autumn olive and oriental bittersweet and triclopyr is not as effective on shrub honeysuckers and grasses. Mixing these together will solve this issue.

The only problem occurs when you mix both the compounds at a very high concentration. This will result in some particles bonding together and forming solid particles, which can block the sprayer nozzle if this is the chosen method of delivery.

You can take care of this issue by mixing triclopyr first to 75% of the final mixture and adding glyphosate only once triclopyr has been properly mixed. This is because both the chemicals will come in contact when they have been diluted in the final mixture.

It is also not recommended to mix more than 15 gallons of the chemicals at a time.

When Should You Choose Glyphosate?

Glyphosate is perfect for situations where you have to get rid of a large variety and number of weeds and plants or if you want to clear large areas of grass. It is a good herbicide to get a ‘clean slate’ on your property.

When Should You Go for Triclopyr?

Triclopyr is perfect when you have to get rid of some specific species of plants or if you have to kill woody plants or for removing unwanted plants in the middle of a lawn.

Conclusion

Triclopyr and glyphosate are some of the most widely used herbicides in the world. Both of them are synthetic systemic chemicals. While glyphosate is effective on most vegetation species, triclopyr is selective in nature and is rarely ever effective on grass. While triclopyr acts faster, it is also slightly more toxic for humans.