Propanil Herbicide | Selective Post-Emergence Weed Control for Rice

Propanil is a selective post-emergence herbicide from the aniline family, specifically developed for annual grass and broadleaf weed control in rice paddies. As a photosystem II (PSII) inhibitor, it disrupts photosynthesis in target plants, leading to rapid chlorosis and death. Its fast action, rice-specific safety, and low soil residual make it a staple in global rice weed management programs.

Technical Specifications

Active Ingredient: Propanil (CAS No. 709-98-8)
Molecular Formula: C₁₂H₁₄ClNO₂
Mode of Action: Inhibits photosystem II, blocking electron transport in chloroplasts.
Formulation: 340g/L EC (Emulsifiable Concentrate)
Target Crop: Rice (paddy and upland)
Target Weeds:
- Annual Grasses: Barnyardgrass, crabgrass, foxtail.
- Broadleaf Weeds: Duckweed, waterwort, amaranth.
- Sedges: Green foxtail, flatsedge (suppression).

Mode of Action

Foliar Uptake: Rapidly absorbed by weed leaves during post-emergence application.
PSII Inhibition: Binds to the D1 protein in PSII, blocking electron flow from water to plastoquinone.
Photosynthetic Disruption:
- Stops ATP and NADPH production, halting carbon fixation.
- Generates reactive oxygen species (ROS), damaging chloroplast membranes.
Symptom Progression:
- 24–48 hours: Initial chlorosis (yellowing) at leaf tips.
- 5–7 days: Widespread necrosis (browning) and plant collapse.

Application Tips:

Water Management: Maintain 3–5 cm water depth for 3–5 days post-application in paddy fields.
Mixing: Dilute in 300–500 L water/ha; add non-ionic surfactant for optimal leaf adhesion.
Timing: Apply in cool mornings (15–25°C); avoid spraying during midday heat or drought.

Key Advantages

Rice-Specific Selectivity: Safe for rice due to rapid metabolic detoxification (glucoside conjugation).
Fast Action: Visible weed control within 48 hours, ideal for late-season infestations.
Low Soil Residue: Half-life of 7–14 days, minimal impact on rotational crops.
Tank Mix Compatibility:
- Common Mixes: Molinate, thiobencarb (enhances grass control).
- Synergy: With bentazone for broadleaf/sedge suppression.
Cost-Effective: Affordable post-emergence solution for rice growers.

Safety & Environmental Notes

Toxicity: Low mammalian toxicity (LD₅₀ > 2000 mg/kg); moderate toxicity to fish and algae.
Environmental Impact:
- Rapid degradation in water (half-life: 2–5 days) via photolysis.
- Minimal soil mobility; low risk of groundwater contamination.
Storage: Store in cool, dry place; protect from direct sunlight.

Resistance Management

HRAC Group: 7 (PSII inhibitors).
Strategies:
- Rotate with Group 15 (S-metolachlor) or Group 2 (bensulfuron-methyl).
- Avoid consecutive annual use to prevent PSII-resistant weed development.

FAQ

Can Propanil be used in organic rice farming?
No; it is a synthetic herbicide prohibited in organic systems.
How does Propanil affect aquatic life?
Toxic to fish and algae; keep 100m from water bodies and avoid runoff.
Is Propanil effective against perennial weeds?
No; targets only annual weeds. Perennials require mechanical or systemic herbicides.
Can it be mixed with other post-emergence herbicides?
Yes; tank mixing with fenchloraz or cyhalofop butyl improves grass control.
What is the pre-harvest interval (PHI)?
PHI is 21 days for rice, ensuring residue compliance with food safety standards.

Packaging & OEM Services

Standard Packaging:
- 1L, 5L, 10L HDPE containers (EC).
Custom Solutions:
- Private labeling with multilingual artwork.
- Regulatory support for global markets (COA, SDS, MRL data).
- Custom blends (e.g., Propanil + molinate combinations).

Why Choose Propanil?

Propanil offers rapid, selective weed control in rice with minimal environmental impact, making it ideal for:

Large-scale rice producers
Flooded paddy systems
Resistance management programs
Export-oriented rice production (meets global MRL standards)

Contact us for bulk orders, technical data sheets, or custom formulation inquiries. Elevate your rice weed management with Propanil—where efficacy meets sustainability.

Recommended Application Rates of Propanil 340EC for Rice Weeding

The optimal application rate of Propanil 340EC (340g/L Emulsifiable Concentrate) depends on rice type, weed species, growth stage, and environmental conditions. Below is a detailed breakdown:

1. General Application Guidelines

Rice Type	Target Weeds	Dosage (L/ha)	Growth Stage
Paddy Rice	Barnyardgrass (Echinochloa crus-galli), duckweed (Lemna spp.), junglerice (Echinochloa colona)	5.6–8.3 L/ha	Weeds at 2–4 leaf stage; rice at 3–4 leaf stage
Upland Rice	Crabgrass (Digitaria spp.), amaranth (Amaranthus spp.), foxtail (Setaria spp.)	7.0–9.7 L/ha	Weeds at 2–5 leaf stage; rice at 4–5 leaf stage
Direct-Seeded Rice	Junglerice, sprangletop (Leptochloa spp.), waterwort (Elatine triandra)	4.2–6.9 L/ha	Weeds at 1–3 leaf stage; rice at 2–3 leaf stage

2. Key Factors Influencing Dosage

Weed Species:
- Tough-to-Control Grasses (e.g., barnyardgrass, junglerice): Use higher rates (7.0–8.3 L/ha).
- Broadleaf Weeds (e.g., duckweed, amaranth): Lower rates (4.2–5.6 L/ha) may suffice.
Growth Stage:
- Young Weeds (1–3 leaves): Use lower rates (4.2–5.6 L/ha).
- Mature Weeds (4+ leaves): Require higher rates (7.0–9.7 L/ha) or tank mixes.
Environmental Conditions:
- Cool, Humid Weather: Enhanced efficacy; standard rates apply.
- Hot, Dry Conditions: May require higher rates (up to 9.7 L/ha) for penetration.

3. Tank Mix Recommendations

For Enhanced Grass Control:
- Propanil 340EC + Molinate (1.5–2.0 L/ha) for barnyardgrass.
- Propanil 340EC + Thiobencarb (2.0–3.0 L/ha) for sprangletop.
For Broadleaf/Sedge Control:
- Propanil 340EC + Bentazone (0.5–1.0 L/ha) for duckweed and flatsedge.

4. Application Tips

Water Volume:
- Use 300–500 L/ha of water for thorough coverage.
- Add non-ionic surfactant (0.25–0.5% v/v) to improve leaf adhesion.
Timing:
- Apply in early morning (15–25°C) to avoid midday heat stress.
- Paddy Rice: Maintain 3–5 cm water depth for 3–5 days post-application.
Calibration:
- Adjust spray nozzles to medium-fine droplets (200–300 μm) for optimal coverage.

5. Safety & Compatibility

Resistance Management: Rotate with Group 15 (e.g., S-metolachlor) or Group 2 (e.g., bensulfuron-methyl) to prevent PSII-resistant weeds.
Phytotoxicity Risk: Avoid mixing with organophosphate insecticides (e.g., chlorpyrifos) to prevent rice injury.

6. Example Calculation

For paddy rice treating barnyardgrass at 2–4 leaf stage:

Dosage: 6.9 L/ha of Propanil 340EC
Water Volume: 400 L/ha
Mixing:
1. Fill spray tank with 50% water.
2. Add 6.9 L of Propanil 340EC.
3. Add 1–2 L of non-ionic surfactant.
4. Top up with remaining water and agitate thoroughly.