What is the Difference Between 2 4-D Amine and Ester

The key difference between 2 4-D amine and ester is that 2 4-D amine has a low vapor pressure compared to 2 4-D esters.

2,4-D amine and ester are both formulations of one of the oldest and most widely used herbicide categories. Compounds with 2,4-D structure belong to the same group of herbicides named phenoxy-carboxylic acids. We can use the herbicides in this group for annual, biennial, and perennial broadleaf weeds. However, it has little effect on grasses. The two major formulations of 2,4-D are amine salts and esters.

CONTENTS

1. Overview and Key Difference
2. What is 2 4-D Amine 
3. What is 2 4-D Ester 
4. 2 4-D Amine vs Ester in Tabular Form
5. Summary – 2 4-D Amine vs Ester

What is 2 4-D Amine?

2,4-D amine is a selective post-emergent herbicide that is a post-emergent weed killer useful in eliminating broadleaf weeds and brush. Generally, the mixing ratio of this herbicide is 2.5 oz of 2,4-D weed killer with 1 gallon of water. This amount can be used to treat about 400 square feet of weed-infected area in the yard. Similarly, if we are using this herbicide on 800 to 1000 square feet of weed-laden grass, we can double the amount of herbicide that is dissolved in water (5 oz).

Typically, 2,4-D amines have a comparatively lower vapor pressure; a lower vapor pressure can cause a decreased volatilization. Therefore, amines are comparatively less volatile. This substance is formulated to protect most grassy lawns, turfs, and various crop areas from unwanted weeds. In addition, we can use it to control unwanted aquatic weeds and trees.

Many people tend to use this amine form when the volatilization around sensitive plants is an important factor to be concerned about. This is because volatility can increase in hot, dry weather.

What is 2 4-D Ester?

2,4-D ester is a selective post-emergent herbicide having an ester functional group in its chemical structure. This substance has a high vapor pressure. Therefore, it tends to volatilize more than amines. Many people use the ester form when there is less concern about volatility. There are several ester formulations as long chain esters can make the molecule less volatile. However, esters are comparatively more volatile than amines.

Moreover, 2,4-D esters provide more weed control than the amine form, which makes it to be known as “hotter,” meaning it can have a high effectivity on plants. Sometimes, this can cause crop injuries as well. Since esters are more soluble in the plant’s cuticle, they are more active in plants. Therefore, it makes the plants absorb the ester form more quickly.

What is the Difference Between 2 4-D Amine and Ester?

The key difference between 2 4-D amine and ester is that 2 4-D amine has a low vapor pressure than 2 4-D esters. Moreover, 2 4-D esters are more volatile than 2,4-D amines. Another difference between 2 4-D amines and ester is their ability to dissolve in plant cuticles. Since esters are more soluble in the plant’s cuticle, they are more active on plants; however, 2 4-D amines are less soluble in plant cuticles.

The below infographic presents the differences between 2 4-D amine and ester in tabular form for side-by-side comparison.

Summary – 2 4-D Amine vs Ester

Herbicides are important chemical components in agriculture. The 2,4-D herbicide is a famous form of herbicide that has been used for a long time. The two major formulations of 2,4-D are amine salts and esters. The key difference between 2 4-D amine and ester is that 2 4-D amine has a low vapor pressure compared to 2 4-D esters.

Reference:

1. R, Jamie John, et al. “Kills Everything in Its Path.” Solutions Pest & Lawn, 22 June 2022.

Image Courtesy:

1. “Lantana 2-4-D effect close up” By Mark Marathon – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “2-4 Dow weed killer” By Producer: Handy (Jam) Organization Sponsor: Dow Chemical Corporation – Death to Weeds (1947), (Public Domain) via Commons Wikimedia