Atrazine: A Broad-Spectrum Triazine Herbicide

Technical Introduction

Atrazine (IUPAC: 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine) is a selective, systemic herbicide in the triazine family.

It is one of the most widely applied herbicides worldwide, mainly for broadleaf and grassy weed control in maize, sorghum, and sugarcane.

• Mode of Action: Photosystem II (PSII) inhibitor — blocks electron transport in photosynthesis, leading to disruption of energy production (HRAC Group C1).

• Systemicity: Absorbed mainly by roots, with upward translocation through the xylem.

• Selectivity: Target crops metabolize Atrazine more quickly, allowing selective weed control.

Applications

• Major Crops:

  • Maize, sorghum, sugarcane, pineapple, and certain conifer plantations.

• Weed Spectrum:

  • Controls a wide range of annual broadleaf weeds (Amaranthus spp., Chenopodium spp., Stellaria media) and some annual grasses (Setaria spp., Digitaria spp.).

• Application Timing:

  • Applied pre-emergence (before weeds germinate) or early post-emergence (when weeds are young and actively growing).

• Tank Mixtures:

  • Commonly used with metolachlor, acetochlor, mesotrione, or simazine for extended weed spectrum and resistance management.

Advantages

• Broad-Spectrum Weed Control: Effective against both broadleaf and grassy weeds.

• Versatility: Can be applied pre- or post-emergence, depending on crop needs.

• Residual Activity: Provides 4–8 weeks of soil residual control, reducing the need for repeat applications.

• Compatibility: Works well in tank mixtures and pre-mix formulations.

• Proven Performance: Decades of use in major cropping systems worldwide.

Specifications (Typical Parameters)

FAQ

Q1: What crops is Atrazine used in?
A: Primarily maize, sorghum, sugarcane, pineapple, and in forestry (conifers).

Q2: Does Atrazine control perennial weeds?
A: It is mainly effective on annual broadleaf weeds and some grasses. Perennials require additional control measures.

Q3: Can Atrazine be applied post-emergence?
A: Yes, it can be applied early post-emergence when weeds are small, but crop selectivity must be respected.

Q4: How long does Atrazine last in soil?
A: Typically 4–8 weeks, depending on soil type, temperature, and rainfall.

Q5: Is Atrazine safe for the environment?
A: Atrazine has been linked to groundwater contamination, so its use is restricted or banned in some regions (e.g., the EU). In regulated markets, application must follow strict guidelines.

Q6: What is the typical application rate?
A: Usually 0.5–2.0 kg a.i./ha, depending on crop, soil type, and weed pressure.