Mefenacet 50% WP Herbicide

Product name	Mefenacet 50% WP
Active ingredient	Mefenacet
CAS number	73250-68-7
Content	50% w/w (wettable powder)
Appearance	Off-white to light brown free-flowing powder
Formulation type	WP (Wettable Powder)
Wetting time	Meets standard wetting time requirement
Suspensibility	≥ 70–80% (typical spec, CIPAC method)
Wet sieve test	Residue ≤ 2.0% through 75 μm sieve
pH (1% suspension)	6.0–9.0
Moisture	≤ 2.0%
Packaging	500 g / 1 kg foil bags; 10–25 kg bulk bags (OEM options)
Intended use	Selective herbicide for transplanted rice (where registered)

Mefenacet 50% WP Herbicide for Transplanted Rice

Mefenacet 50% WP is a selective wettable-powder herbicide developed for transplanted rice. It is widely used across Asia to control barnyardgrass and other early-emerging grass weeds that compete heavily with young rice seedlings.

The product works through root and coleoptile absorption and moves upward in the plant, where it inhibits cell division and early growth. This allows it to stop grass weeds before they establish, while maintaining good crop safety when applied within the recommended timing.

The formulation is a 50% wettable powder, suitable for standard paddy-field practices such as sand-mix broadcasting or spray application (according to local label requirements). Its reliability and compatibility with transplanted rice systems make it a strong fit for distributors serving China, Vietnam, Thailand, India, Japan, Korea and other rice-producing markets.

Key points for your customers:

• Effective on barnyardgrass, the most problematic weed in paddy fields
• Designed for pre-emergence and early post-emergence use
• Selective to transplanted rice when applied at proper timing
• WP format offers cost-efficient handling and easy mixing
• Suitable for OEM/private label programs in multi-language packaging

Mode of Action & Selectivity

Mefenacet belongs to the acetanilide/benzothiazole herbicide group and provides selective control of early-stage grass weeds in transplanted rice. The product is absorbed mainly through the roots and coleoptile of germinating weeds. After uptake, it moves upward in the plant and inhibits cell division and growth at the meristem, preventing weeds from emerging or developing beyond the early stages.

This mode of action delivers:

• Strong activity against barnyardgrass and other common paddy grasses
• Reliable performance in flooded or moist soil conditions
• Good crop safety when used within the labelled timing window
• Effective suppression of early-season competition, helping rice seedlings establish uniformly

Because Mefenacet targets sensitive growth points in young weeds, the product performs best when applied before emergence or shortly after germination, under stable water conditions as defined by the local label.

Target Weeds and Rice Application Fit

Mefenacet 50% WP is designed for transplanted rice paddies and focuses on the early control of grass weeds that compete most strongly with young rice.

Typical targets include:

• Barnyardgrass (Echinochloa spp.) – primary target and key value driver
• Other annual paddy grasses emerging together with rice
• Certain mixed weed populations when used in programmes or premixes with other herbicides

The product is best suited for:

• Transplanted rice fields with stable water management
• Fields where barnyardgrass is the dominant problem weed
• Programs aiming for clean, early fields to reduce later weed pressure and labour

On its own, Mefenacet 50% WP focuses on grass weed control. In many markets it is also used as part of premixes or tank-mix programmes with sulfonylureas or other partners to broaden activity on broadleaf weeds and sedges, depending on local registration.

Formulation & Product Features of Mefenacet 50% WP

Mefenacet 50% WP is a wettable powder formulation designed for easy handling in paddy-field conditions and for flexible use by distributors and applicators.

Key formulation features:

• 50% active ingredient content – concentrated enough for efficient transport and storage
• Free-flowing wettable powder – designed to disperse quickly in water with proper agitation
• Suitable for sand-mix broadcasting or spray application, depending on local label and practice
• Compatible with common rice herbicide programmes, including premix or separate application with sulfonylurea partners

For distributors, the WP format provides a cost-effective, familiar option in many Asian rice markets where powdered formulations are still widely accepted and easy to distribute in small packs.

Application Timing and Use Principles

Final instructions must always follow the registered label in each country, but the practical positioning is:

• Target crop: transplanted rice
• Typical timing: within 1–7 days after transplanting, when weeds are at pre-emergence to early leaf stage
• Best performance: under shallow, stable water layer in the paddy, as defined by local agronomy and label
• Usual practice: applied once per season as an early-season foundation treatment to keep the field clean during establishment

Mefenacet 50% WP works best when water management, timing and dose all align with the labelled recommendations, ensuring strong barnyardgrass control with good crop safety.

Use Rate Logic for Mefenacet 50% WP

Mefenacet 50% WP is typically positioned in a moderate-rate range for transplanted rice, with the exact dose defined strictly by each country’s registered label.

General use logic for positioning:

• Most programmes fall within a 600–1500 g/ha product range, depending on weed pressure and formulation.
• Some labels or mixtures specify narrower examples such as ~600 g/ha or 375–1200 g/ha, depending on local agronomy.
• Dose decisions mainly depend on:
  • Barnyardgrass pressure and weed diversity
  • Water management stability in the field
  • Soil type and organic matter
  • Whether the product is applied alone or as part of a premix

Because dose is highly regulated in rice systems, you should always direct customers to follow local label guidance rather than using generalised numbers. For distributors, this section helps communicate why dose ranges differ between formulations and markets, without providing any operational details.

Combination Options & Portfolio Fit

Mefenacet is frequently used in premix or programme-based approaches to widen weed coverage in paddy fields. Its strong grass control provides a solid base when paired with herbicides targeting broadleaf weeds or sedges.

Common industry combinations (depending on local registration):

• Mefenacet + Bensulfuron-methyl / Pyrazosulfuron-ethyl / Imazosulfuron
  Expands control to broadleaf weeds and sedges.
• Mefenacet + Butachlor / Pretilachlor / Oxadiazon
  Strengthens overall control of paddy grasses and early-season mixed weeds.
• Mefenacet + Bentazone / Fenclorim
  Used in some markets for improved crop safety or spectrum adjustment.

This positioning allows you to present Mefenacet 50% WP not only as a standalone grass herbicide, but also as a flexible building block in a full rice-herbicide portfolio for Asian markets.

Market Focus and Application Regions

Mefenacet 50% WP is primarily positioned for paddy-rice markets in Asia-Pacific, where transplanted rice and flooded-field management are standard practice.

Key application regions include:

• China, Japan, Korea – long-term use of Mefenacet-based products in intensive rice systems
• Vietnam, Thailand, Indonesia – strong demand for early barnyardgrass control in transplanted rice
• India and South Asia – used as part of pre- and early post-emergence rice herbicide programmes

In these markets, Mefenacet is often available both as single-ingredient 50% WP and as premix products with sulfonylureas or other rice herbicides, giving distributors flexibility to match local weed spectra and pricing tiers.

Outside Asia, Mefenacet use is limited or niche, and it is not a mainstream product in the United States. As a result, Mefenacet 50% WP should be positioned mainly as an Asia-focused rice herbicide, targeting importers, formulators and distributors who specialise in paddy-rice solutions.

For your portfolio, this means Mefenacet 50% WP is best used to:

• Strengthen your rice herbicide range in existing APAC markets
• Support local partners who already manage transplanted rice under flooded conditions
• Build country-specific product lines (single and premix) adapted to each market’s registration and weed profile

Packaging and OEM Service

Mefenacet 50% WP is well suited to small pack formats for rice markets and bulk packs for local formulators.

Typical options:

• Retail / farm packs
  • 500 g foil bag
  • 1 kg foil bag or laminated bag
• Bulk packs for repacking or local blending
  • 10 kg / 20 kg / 25 kg multi-wall or woven composite bags

OEM / private label capabilities:

• Custom brand design and layout for rice herbicide ranges
• Multi-language artwork (e.g. English, Vietnamese, Thai, Hindi, Chinese, etc.)
• Alignment with local regulatory requirements for label text and safety icons

This allows you to integrate Mefenacet 50% WP into an existing rice herbicide brand family or build a new line from zero.

Quality Control and Documentation

To support professional distributors and registration work, Mefenacet 50% WP is backed by a standard QC and documentation package:

• Batch-level QC
  • Active ingredient content
  • Moisture, suspensibility, wet sieve, pH
  • Low- and high-temperature storage checks
• Documentation package
  • COA (Certificate of Analysis) for each batch
  • MSDS / SDS compliant with international transport rules
  • TDS with key technical and handling information
  • Supporting data for stability or registration (where available and agreed)

This gives your customers confidence in consistency, safety and traceability across shipments.

FAQ

Q1. Is Mefenacet 50% WP suitable for direct seeding rice?
Mefenacet is mainly positioned for transplanted rice. Use in direct-seeded rice depends on local registration and label conditions and should be confirmed case by case.

Q2. Can Mefenacet 50% WP be premixed with sulfonylurea herbicides?
Yes, many markets already use Mefenacet in premixes or programmes with sulfonylureas to broaden weed control. Any new formulation or mixture must respect local registration and possible formulation patents.

Q3. How should we position Mefenacet 50% WP in our portfolio?
As a core barnyardgrass solution for transplanted rice in Asia-focused markets, either as a standalone grass herbicide or as a base active for rice herbicide premix lines.

Work with Us on Mefenacet 50% WP

If your business focuses on paddy-rice markets in Asia-Pacific and you want to:

• Strengthen your barnyardgrass control products
• Extend a rice herbicide portfolio with a proven active ingredient
• Develop OEM or private-label solutions with flexible packaging and documentation

we can supply Mefenacet 50% WP with:

• Stable quality and competitive pricing
• COA, MSDS, TDS and registration support
• Custom packaging and multi-language label design

You can use this section as the closing block on the product page to encourage inquiries from importers, distributors and formulators.