Acetochlor: A Pre-Emergence Herbicide for Broadleaf and Grass Weed Control

Technical Introduction

Acetochlor (IUPAC: 2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide) is a selective pre-emergence herbicide of the chloroacetamide class.

It is primarily used for annual grass weeds and some broadleaf weeds, providing protection to crops during the early stages of growth.

• Mode of Action: Inhibits very long chain fatty acid (VLCFA) synthesis, preventing cell division and seedling development (HRAC Group K3).

• Systemicity: Absorbed mainly by germinating seeds and shoots through the soil.

• Selectivity: Safe for major row crops at recommended rates, especially maize and soybean.

Applications

• Row Crops:

  • Widely used in maize, soybean, sugarcane, cotton, peanuts, and sunflower for pre-emergence weed control.

• Weed Spectrum:

  • Controls annual grasses (e.g., Setaria, Echinochloa, Digitaria, Eleusine spp.) and some broadleaf weeds (e.g., Amaranthus, Chenopodium).

• Application Timing:

  • Applied pre-emergence after sowing and before weed germination.

  • Requires rainfall or irrigation for activation.

Advantages

• Broad-Spectrum Control: Effective against annual grasses and certain broadleaf weeds.

• Residual Activity: Provides 4–6 weeks of soil residual control, reducing early weed competition.

• Crop Safety: Selective for maize, soybeans, and other row crops at proper dosage.

• Flexible Formulations: Available as EC, CS, and microencapsulated (ME) for extended release.

• Compatibility: Can be tank-mixed with atrazine, mesotrione, or glyphosate for broader weed control.

Specifications (Typical Parameters)

FAQ

Q1: What crops is Acetochlor safe for?
A: Mainly maize, soybean, peanuts, cotton, sunflower, and sugarcane, but crop-specific selectivity must be respected.

Q2: Does Acetochlor control emerged weeds?
A: No, it is a pre-emergence herbicide and must be applied before weed germination.

Q3: Can Acetochlor be mixed with other herbicides?
A: Yes, it is often combined with atrazine, mesotrione, or glyphosate for broader-spectrum weed control.

Q4: How long does Acetochlor remain active in soil?
A: Residual activity usually lasts 4–6 weeks, depending on soil type and environmental conditions.

Q5: Is Acetochlor safe for the environment?
A: It has moderate mammalian toxicity and potential groundwater contamination risks, so application must follow regulatory guidelines.

Q6: What is the typical application rate?
A: Usually 1.5–3.0 L/ha (750–1500 g a.i./ha) depending on crop and soil condition.