Metribuzin 70% WDG Herbicide | Selective Pre- and Post-Emergent Weed Control

Technical Specifications

• Active Ingredient: Metribuzin (CAS No. 21087-64-9)
• Molecular Formula: C₈H₁₄N₄OS
• Molecular Weight: 214.29 g/mol
• Mode of Action: Inhibits PSII electron transport, blocking ATP and NADPH production
• Formulation: 70% WDG (700 g/kg active ingredient)
• Physical State: Off-white water-dispersible granules
• Solubility: 1.2 g/L in water at 20°C
• Soil Half-Life: 30–60 days (varies with pH and microbial activity)
• Toxicity: WHO Class III (slightly hazardous); LD₅₀ > 2000 mg/kg (rat oral)

Mode of Action

1. Dual Uptake Pathways:
   • Root Absorption: Pre-emergent application inhibits germinating seedlings.
   • Foliar Uptake: Post-emergent spray is absorbed by leaves, translocating to meristematic tissues.
2. Photosynthetic Disruption:
   • Binds to the D1 protein in PSII, blocking electron flow from water to plastoquinone.
   • Disrupts carbon fixation, leading to oxidative stress and pigment degradation.
3. Symptom Progression:
   • 3–5 days: Initial chlorosis in older leaves
   • 7–10 days: Widespread necrosis and plant death

Application Guide

Application Best Practices

• Water Volume: 200–400 L/ha for uniform coverage
• Soil Moisture: Optimal efficacy requires 10–20 mm rainfall/irrigation post-application
• Tank Mixes:
  • With acetochlor for enhanced grass control in corn
  • With sulfentrazone for resistant broadleaves in soybeans
• Adjuvants: Add non-ionic surfactant (0.25% v/v) for post-emergent applications

Key Advantages

1. Broad-Spectrum Efficacy: Controls 40+ weed species, including Amaranthus, Setaria, and Chenopodium.
2. Residual Activity: 4–6 weeks of soil protection reduces re-application needs.
3. Crop Selectivity: Safe for soybeans, potatoes, and tolerant corn when used at labeled rates.
4. Flexible Application: Suits no-till, conventional tillage, and aerial spraying systems.
5. Resistance Management: Compatible with Group 15 (e.g., S-metolachlor) and Group 9 (glyphosate) for rotation.

Safety & Environmental Notes

• Ecotoxicity:
  • Toxic to fish and algae (LC₅₀ < 1 mg/L); maintain 100 m buffer from water bodies.
  • Low toxicity to birds (LD₅₀ > 1000 mg/kg).
• Environmental Fate:
  • Moderate soil mobility in sandy soils; potential groundwater risk.
  • Degrades via microbial action and photolysis, slower in alkaline soils (pH >7).
• Storage: Store at 5–30°C, protected from moisture and direct sunlight.

Packaging & Compliance

• Standard Packs: 1kg, 5kg, 25kg moisture-proof bags
• Custom Solutions:
  • Private labeling with multilingual instructions
  • OEM formulations for regional registration
• Regulatory Support:
  • COA, MSDS, and residue data for EU, EPA, and APAC markets
  • Compliance with FAO/WHO Good Agricultural Practices

FAQ

• High OM soils ( >3%) require higher rates (560 g/ha)
• Sandy soils risk leaching; use lower rates (280 g/ha) and avoid pre-rain application

• Avoid application under stress (drought, flooding)
• Test on a small plot before full-scale use in sensitive crops like corn

Tank Mix Combinations

Resistance Management

• FRAC Group: 5 (PSII inhibitors)
• Rotation Strategies:
  • Alternate with Group 15 (S-metolachlor) or Group 2 (chlorimuron-ethyl)
  • Avoid consecutive applications; limit to 2–3 times per season
• Resistance Warning:
  • Reported in Amaranthus palmeri and Chenopodium album in continuous soybean systems

Real-World Applications

• Midwestern Soybeans: 420 g/ha Metribuzin + 1.5 L/ha acetochlor controlled 90% of annual weeds in no-till systems.
• Potato Farms in Idaho: 840 g/ha pre-emergent reduced weed competition, increasing yield by 18%.
• Corn in Argentina: 350 g/ha + 2.0 L/ha atrazine provided season-long control of Setaria viridis.

Environmental Stewardship

• Reduced Spray Passes: Residual activity minimizes tractor traffic and fuel use.
• Bee Safety: Apply before crop flowering; avoid drift to blooming plants.
• Soil Health: Compatible with conservation tillage practices.