Oxadiazon 26% EC Herbicide | Pre-Emergent Weed Control for Rice, Vegetables

Oxadiazon 26% EC (Emulsifiable Concentrate) is a selective pre-emergent herbicide designed to control annual broadleaf weeds, grasses, and sedges in rice, vegetables, turfgrass, and orchards. As a protoporphyrinogen oxidase (PPO) inhibitor, it disrupts cell membrane integrity, leading to rapid weed desiccation and death. The EC formulation ensures easy mixing and uniform coverage, providing long-lasting residual activity in soil.

Technical Specifications

Parameter	Details
Active Ingredient	Oxadiazon (CAS No. 19666-30-9)
Chemical Class	Oxadiazole
Mode of Action	PPO inhibitor (HRAC Group 14)
Formulation Type	26% EC (260 g/L active ingredient)
Appearance	Yellowish-brown liquid
Solubility	0.07 mg/L in water (20°C)
pH Range	5.0–8.0
Density	1.05–1.15 g/cm³

Mode of Action

Soil Absorption:
- Taken up by germinating seedlings through roots and shoots.
Biochemical Disruption:
- Inhibits PPO enzyme, causing accumulation of toxic intermediates that destroy cell membranes.
Symptom Progression:
- 1–3 days: Rapid wilting and bleaching of emerging seedlings
- 5–7 days: Complete desiccation and death

Application Guide

Crop	Target Weeds	Dosage (L/ha)	Application Timing
Rice	Barnyardgrass, Monochoria, sedges	1.5–2.5	Pre-emergence (0–5 days after sowing)
Vegetables	Pigweed, lambsquarters, crabgrass	1.0–2.0	Pre-plant incorporation or pre-emergent
Turfgrass	Annual bluegrass, chickweed	1.0–1.5	Pre-emergence in established turf
Orchards	Foxtail, groundsel	2.0–3.0	Pre-emergence, directed spray to soil

Application Tips

Water Volume: 300–500 L/ha for soil incorporation
Adjuvants: Not required for pre-emergent applications
Tank Mixes:
- With pendimethalin for broader spectrum in vegetables
- With quinclorac for enhanced grass control in rice
Soil Conditions: Apply to moist, well-prepared soil; incorporate mechanically or with irrigation (5–10 mm)

Key Advantages

Broad-Spectrum Control:
- Effective against 30+ annual weeds, including many herbicide-resistant biotypes.
Long Residual Activity:
- Provides 4–6 weeks of soil protection, reducing weed pressure during crop establishment.
Crop Safety:
- Selective in rice, vegetables (e.g., tomatoes, peppers), and turf when applied pre-emergent.
Low Volatility:
- Minimizes risk of drift damage to neighboring crops.
Environmental Profile:
- Low mammalian toxicity (LD₅₀ > 5000 mg/kg)
- Soil-bound with minimal leaching potential (DT₅₀ 30–60 days)

Safety & Environmental Notes

Toxicity:
- Moderate toxicity to fish (LC₅₀ 1–10 mg/L); avoid water bodies.
- Toxic to aquatic invertebrates; maintain 100 m buffer from waterways.
Storage:
- Store at 5–35°C; protect from freezing.
Handling:
- Wear protective clothing; avoid contact with skin and eyes.

Packaging & Compliance

Standard Packs: 1L, 5L, 20L COEX containers
Custom Solutions:
- Private labeling with multilingual instructions
- Regulatory support for global markets (EPA, EU, APAC)
Shelf Life: 3 years under recommended storage conditions

FAQ

Q1: Can Oxadiazon 26% EC be used post-emergence?
A: No, it is strictly a pre-emergent herbicide. Post-emergent applications will not control established weeds.

Q2: What is the pre-harvest interval (PHI)?
A: PHI varies by crop:

Rice: 60 days
Vegetables: 30–45 days (check label for specific crops)
Turfgrass: No restrictions (non-food crop)

Q3: How to handle resistance management?
A: Rotate with Group 15 (e.g., S-metolachlor) or Group 3 (e.g., trifluralin) herbicides.

Q4: Can it be used in flooded rice fields?
A: Yes, but ensure uniform distribution in shallow water (3–5 cm) and maintain flood for 5–7 days.

Q5: Does Oxadiazon require soil incorporation?
A: Yes, for optimal efficacy, incorporate into the top 2–3 cm of soil via irrigation or mechanical means.

Field Performance

Rice Trials in Vietnam:
2.0 L/ha controlled 95% of barnyardgrass and 88% of Monochoria for 45 days.
Vegetable Trials in California:
1.5 L/ha + pendimethalin reduced weed density by 92% in tomato fields.

FAQ: Oxadiazon 26% EC Herbicide

1. What is Oxadiazon 26% EC used for?

Oxadiazon 26% EC is a pre-emergent herbicide designed to control annual broadleaf weeds, grasses, and sedges in rice, vegetables, turfgrass, and orchards. It prevents weed germination and early growth by disrupting cell membrane formation in seedlings.

2. How does Oxadiazon 26% EC work?

As a PPO (protoporphyrinogen oxidase) inhibitor, it blocks an enzyme critical for chlorophyll and cell membrane synthesis. Germinating weeds absorb it through roots/shoots, leading to rapid wilting, bleaching, and death within 1–3 days.

3. What is the recommended application rate?

Rice: 1.5–2.5 L/ha (pre-emergent, 0–5 days after sowing)
Vegetables: 1.0–2.0 L/ha (pre-plant or pre-emergent)
Turfgrass: 1.0–1.5 L/ha (pre-emergent in established turf)
Orchards: 2.0–3.0 L/ha (directed soil spray)

4. Can I use it in flooded rice fields?

Yes, apply to shallow-flooded soil (3–5 cm water) and maintain flooding for 5–7 days. This enhances soil adsorption and weed control.

5. Is Oxadiazon 26% EC safe for crops?

When applied pre-emergent as directed, it is selective for rice, vegetables (e.g., tomatoes, peppers), and turf. Avoid post-emergent use, as it may damage crop seedlings.