Bispyribac-sodium 40% SC Herbicide

Technical Specifications

• Active Ingredient: Bispyribac-sodium (CAS No. 125401-92-5)
• Molecular Formula: C₁₂H₁₁N₂NaO₄F₃S
• Mode of Action: Inhibits acetolactate synthase (ALS), blocking leucine, isoleucine, valine synthesis
• Formulation: 40% SC (400 g/L active ingredient)
• Physical State: Off-white flowable suspension
• Solubility: 2.7 g/L in water at 20°C
• pH Range: 6.0–8.0 (stable in neutral conditions)
• Viscosity: 200–400 cP (at 25°C)

Mode of Action

1. Foliar Uptake & Translocation:
   • Absorbed by weed leaves and stems, translocated to meristematic tissues via phloem.
2. Biochemical Blockade:
   • Inhibits ALS enzyme, preventing branched-chain amino acid biosynthesis.
   • Disrupts cell division and protein synthesis in growing points.
3. Symptom Progression:
   • 3–5 days: Initial chlorosis in new growth
   • 7–10 days: Widespread necrosis, stunted growth, and plant death

Application Guide

Application Best Practices

• Water Management: Maintain 3–5 cm water depth for 3–5 days post-application.
• Spray Parameters: Use 300–500 L/ha water volume; fine to medium droplet size.
• Tank Mixes:
  • With fenchloraz for enhanced grass control
  • With bentazone for broadleaf weed synergism
• Adjuvants: Add non-ionic surfactant (0.2% v/v) to improve leaf adhesion.

Key Advantages

1. Selective Weed Control:
   • Effective against 20+ broadleaf and sedge species in rice.
   • Safe for rice due to metabolic detoxification (glucoside conjugation).
2. Residual Activity:
   • 14–21 days of soil residual control, reducing re-application needs.
3. Flexible Application:
   • Suits both early and late post-emergence stages (2–5 leaf weed growth).
4. Resistance Management:
   • Belongs to HRAC Group 2 (ALS inhibitors); rotate with Group 15 (e.g., S-metolachlor).
5. Environmental Profile:
   • Low mammalian toxicity (LD₅₀ > 2000 mg/kg); rapid soil degradation (DT₅₀ 10–15 days).

Safety & Environmental Notes

• Toxicity:
  • Low acute toxicity to mammals; highly toxic to fish (LC₅₀ < 1 mg/L).
  • Avoid application near water bodies; maintain 50 m buffer zone.
• Environmental Fate:
  • Soil half-life: 10–15 days (microbial degradation).
  • Low volatility; minimal risk of vapor drift.
• Storage: Store at 5–30°C, protected from sunlight and freezing.

Packaging & Compliance

• Standard Packs: 1L, 5L, 20L HDPE containers
• Custom Solutions:
  • Private labeling with multilingual instructions
  • Regional formulation adjustments (e.g., anti-freeze agents)
• Regulatory Support:
  • COA, MSDS, and residue data for global markets
  • Compliance with FAO, EPA, and APAC regulations

FAQ

1. Can Bispyribac-sodium 40% SC control perennial weeds?
   Effective against annual weeds; limited control of perennials like Cyperus rotundus. Use with mechanical control for perennials.
2. Is it safe for direct-seeded rice?
   Yes, apply 15–25 days after sowing when rice has 3–4 leaves; avoid contact with young seedlings.
3. What is the pre-harvest interval (PHI)?
   PHI is 30 days for rice; ensure compliance with local food safety regulations.
4. Can it be mixed with insecticides?
   Yes, compatible with most insecticides (e.g., chlorpyrifos, lambda-cyhalothrin); jar-test before use.
5. How to manage resistance in target weeds?
   • Rotate with Group 15 (acetochlor) or Group 14 (fomesafen).
   • Avoid consecutive applications; limit to 1–2 times per season.

Field Applications

• Southeast Asia (Transplanted Rice):
  15 g a.i./ha controlled 90% of Monochoria vaginalis and Cyperus difformis in Vietnam rice fields.
• South Asia (Direct-Seeded Rice):
  20 g a.i./ha + 0.5 L/ha bentazone improved broadleaf control by 25% in Indian rice systems.

Residue & Regulatory Status

• MRLs (Key Markets):
  • EU: Rice (0.01 mg/kg)
  • US: Rice (0.1 mg/kg)
• Registration: Approved in China, India, Thailand, and other major rice-producing countries.

Sustainability Features

• Reduced Chemical Inputs: Targeted post-emergence application minimizes over-spray.
• Carbon Footprint: Fewer application passes reduce tractor fuel use.
• Bee Safety: Low toxicity to pollinators (LD₅₀ > 100 μg/bee).