What Is Trifluralin and How Does It Work in Weed Control?

Trifluralin is a pre-emergence dinitroaniline herbicide widely used to control annual grasses and certain broadleaf weeds. It is incorporated into soil before planting to prevent weed seed germination and early development.

Composition

• Chemical name: α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine

• Molecular formula: C₁₃H₁₆F₃N₃O₄

• Appearance: Yellow-orange crystalline solid

• Mode of action: Inhibits microtubule formation during cell division, preventing weed seedling growth.

Key Features

• Highly effective against annual grasses (foxtail, crabgrass, barnyard grass) and some broadleaf weeds.

• Must be incorporated into the soil to avoid breakdown by sunlight.

• Provides residual control lasting several weeks.

• Compatible with various crops such as soybeans, cotton, canola, sunflowers, wheat, and vegetables.

Applications

• Soybeans & Cotton: Early-season control of grassy weeds.

• Wheat & Barley: Pre-plant incorporation for grass suppression.

• Vegetables (carrots, onions, brassicas): Effective in high-value crops for weed-free establishment.

• Ornamentals: Used in nursery and landscape management.

Specifications

• Formulations: 48% EC (emulsifiable concentrate), 60–70% granules, microencapsulated formulations.

• Dosage: Commonly 0.5–2.0 L/ha, depending on soil type and target weeds.

• Soil persistence: Moderately persistent, with a half-life of 45–100 days.

Advantages

• Strong control of annual grasses at germination.

• Reduces the need for repeated post-emergence herbicide sprays.

• Versatile and widely used in row crops and vegetables.

Limitations

• Not effective against established weeds or perennials.

• Requires proper soil incorporation for best results.

• Can persist in soil, raising concerns for crop rotation sensitivity.

• Limited activity on some broadleaf weeds.

FAQs

Q1: How is Trifluralin applied?
It is typically sprayed on soil and then incorporated mechanically or with irrigation to prevent sunlight degradation.

Q2: Can it be used with other herbicides?
Yes, often combined with metribuzin, pendimethalin, or glyphosate for broader control.

Q3: Does Trifluralin pose environmental risks?
Yes. It has low water solubility but can bind strongly to soil and may affect non-target plants if misused.

Q4: How long does its weed control last?
Usually 6–12 weeks, depending on soil conditions and rainfall.