Isoproturon 50% WP: A Potent Solution for Weed Control in Cereal Crops

Isoproturon 50% WP (Wettable Powder) is a highly effective and widely used selective herbicide. As a member of the substituted urea family, it has carved a niche in modern agriculture for its ability to target a diverse range of annual grasses and broadleaf weeds. The 50% WP formulation, containing 500 g/kg of isoproturon as the active ingredient (CAS No. 34123 – 59 – 6), offers excellent dispersibility in water, ensuring uniform application and consistent weed control results. This makes it an essential tool in integrated weed management strategies for cereal crops like wheat, barley, and rye.

Technical Specifications

Parameter	Details
Active Ingredient	Isoproturon
Chemical Class	Substituted urea
Mode of Action	Inhibits photosynthetic electron transport at photosystem II
Formulation	50% WP (500 g/kg active ingredient)
Appearance	Fine off-white powder
Solubility	65 mg/L in water (22°C); soluble in organic solvents (methanol, acetone)
pH Range (suspension)	5.0–8.0

Mode of Action

Root & Leaf Absorption: Primarily taken up by roots, translocated to leaves; minor foliar absorption on young foliage.
Biochemical Disruption: Blocks electron transport in photosystem II, halting ATP and NADPH production, leading to chlorophyll degradation.
Symptom Progression: Chlorosis at leaf tips (2–3 days), widespread wilting and necrosis (5–7 days).

Application Guide

Crop	Target Weeds	Dosage (g ai/ha)	Application Timing
Wheat	Wild oats, annual meadowgrass, chickweed	1000–1500	Pre-emergence (0–5 days after sowing) or early post-emergence (2–3 leaf stage)
Barley	Sterile brome, shepherd’s purse	1200–1600	Pre-emergence; post-emergence on small weeds
Rye	Wild oats, field pansy	1100–1400	Pre-emergence (post-sowing); early post-emergence

Best Practices

Water Volume: 200–400 L/ha for ground application.
Adjuvants: Add 0.2–0.5% non-ionic surfactant for improved adhesion.
Tank Mixes: Combine with diflufenican for broadleaf control in wheat; mix with flufenacet for barley.
Weather: Apply at 10–25°C; avoid rain within 24 hours.

Key Advantages

Broad-Spectrum Control: Targets 40+ annual weeds, including grassy and broadleaf species.
Residual Activity: 3–5 weeks of soil residual control, reducing early-season weed pressure.
Crop Safety: Selective in wheat, barley, and rye when used as directed; temporary leaf discoloration in barley under high humidity is rare and transient.
Cost-Effective: Fewer applications needed vs. single-target herbicides.

Safety & Environmental Notes

Toxicity: Low mammalian toxicity (LD₅₀ > 2000 mg/kg); moderate aquatic toxicity (protect water bodies with 50 m buffer).
Degradation: Soil half-life 14–28 days via microbial action; low volatility and leaching potential.
Storage: Keep at 5–30°C, dry, away from sunlight; shelf life 2–3 years.

Packaging & Compliance

Standard Packs: 1 kg, 5 kg, 25 kg HDPE bags with clear labeling.
Regulatory: Compliant with EU, EPA, and global standards; regional registration support available.

FAQ

Can it control perennials? Primarily for annuals; use the appropriate herbicide for perennials.
Pre-harvest interval (PHI)? 60 days for wheat, 70 days for barley, 65 days for rye.
Water source safety? Maintain 50 m buffer; avoid spraying on slopes near water.
Resistance management? Rotate with Group 2 or 15 herbicides; avoid consecutive annual use.
Organic farming? Not approved; use mechanical or natural methods instead.

Field Performance

UK Wheat Trials: 1200 g ai/ha + diflufenican controlled 90% of wild oats and chickweed, increasing yield by 10–15%.
German Barley Fields: 1400 g ai/ha reduced weed density by 85%, improving grain quality.