Metalaxyl

Metalaxyl Fungicide | High-Efficiency Systemic Control for Oomycete Diseases

Product Name: Metalaxyl
CAS Number: 57837-19-1
Molecular Formula: C₁₅H₂₁NO₄
Mode of Action: Inhibits RNA synthesis in oomycete fungi, blocking their growth and reproduction. Specifically targets pathogens such as Phytophthora and Plasmopara.

Core Application Scenarios

Target Crops

Staple Crops: Potato, Wheat, Sugar Beet
Cash Crops: Grape, Cotton, Tobacco, Cucumber
Horticultural Crops: Vegetables (e.g., Tomato), Turfgrass

Controlled Diseases

Oomycete Diseases: Late Blight, Downy Mildew, Black Shank, Damping-Off, Pythium Blight

Formulations and Application Protocols

Single-Active Formulations

Formulation	Concentration	Key Purpose	Target Diseases	Recommended Crops
Water Dispersible Granule (WDG)	50%	Broad-spectrum disease control	Downy Mildew, Late Blight	Grape, Cucumber, Sugar Beet
Wettable Powder (WP)	35%	Seed treatment & foliar spray	Black Shank, Damping-Off	Tobacco, Cotton
Emulsifiable Concentrate (EC)	240 g/L	Post-emergence systemic control	Phytophthora Blight	Potato, Vegetables
Technical Grade (TC)	98%	Raw material for tank mixes	Broad-spectrum oomycete control	Multi-crop formulations

Co-Formulated Products

Dimethomorph 22% + Metalaxyl 8% WDG: Enhanced efficacy against downy mildew and late blight
Propineb 64% + Metalaxyl 4% WP: Synergistic prevention of fungal leaf spots and oomycete diseases
Metalaxyl 150g/L + Propamocarb 100g/L SC: Soil treatment for root diseases

Application Technical Parameters

Formulation	Crop	Disease	Dosage	Application Method	Critical Timing
8% WDG	Cucumber	Downy Mildew	67–100 g/acre	Foliar spray	At first sign of disease or as preventive
4% WP	Tobacco	Black Shank	60–100 g/acre	Foliar spray	Post-transplant seedling stage
50% WDG	Grape/Beet	Late Blight/Downy Mildew	0.5–1 kg/ha	Foliar application	Pre-flowering to early fruit set

Performance Advantages

Systemic Activity: Absorbed by roots and leaves, providing long-lasting protection through vascular translocation
Rapid Action: Controls early-stage infections within 24–48 hours of application
Resistance Management: Ideal for rotation with other fungicide classes (e.g., strobilurins, copper-based products)
Flexible Use: Suitable for seed treatment, foliar spray, and soil drench applications

Safety and Storage

Precautions: Wear protective clothing and gloves; avoid contact with skin/eyes
Storage: Store in a cool, dry place away from food, feed, and water sources
Shelf Life: 2–3 years under recommended storage conditions

FAQ

1. What is Metalaxyl?

Answer: Metalaxyl is a systemic fungicide belonging to the arylalanine chemical group, specifically designed to control oomycete fungi (e.g., Phytophthora, Plasmopara). It is widely used in agriculture to manage serious crop diseases such as downy mildew, late blight, and black shank on crops like potatoes, grapes, and tobacco.

2. What is the CAS Number of Metalaxyl?

Answer: The CAS Number for Metalaxyl is 57837-19-1. This unique identifier is used for regulatory classification, safety data management, and chemical tracking.

3. How does Metalaxyl work (Mode of Action)?

Answer:

Metalaxyl disrupts RNA synthesis in fungal cells by inhibiting RNA polymerase, an enzyme critical for fungal growth and reproduction.
As a systemic fungicide, it is absorbed by plant tissues and translocated through the vascular system, providing internal protection against both existing and incoming pathogens.

4. What is the difference between Metalaxyl and Metalaxyl-M?

Answer:

Chemical Structure: Metalaxyl-M (mefenoxam) is a stereoisomer of Metalaxyl, featuring a more biologically active configuration.
Efficacy: Metalaxyl-M is generally more potent against specific oomycete diseases (e.g., downy mildew, late blight), while Metalaxyl offers broader-spectrum control across a wider range of fungal pathogens.

5. What diseases does Metalaxyl control?

Answer: Metalaxyl primarily targets diseases caused by oomycetes, including:

Downy mildew (grapes, cucumbers, lettuce)
Late blight (potatoes, tomatoes)
Black shank (tobacco)
Damping-off and root rot (soil-borne pathogens)

6. How is Metalaxyl applied?

Answer: It can be applied via three methods:

Foliar spray: For above-ground disease control (e.g., late blight on potatoes).
Seed treatment: Coating or dressing seeds to protect against soil-borne pathogens (e.g., damping-off).
Soil treatment: Drenching or incorporating into soil to target root infections.

7. Can Metalaxyl be mixed with other fungicides?

Answer: Yes, Metalaxyl is often combined with other fungicides to enhance efficacy and manage resistance:

Common Combinations:
- Metalaxyl + Mancozeb: For late blight control (systemic + contact action).
- Metalaxyl + Chlorothalonil: Broad-spectrum protection against oomycetes and ascomycetes.
- Cymoxanil + Metalaxyl: Synergistic control of downy mildew (contact + systemic).
Avoid Mixing With: Strongly alkaline substances, as they may reduce efficacy.

8. What is Metalaxyl 35 WS used for?

Answer:

35 WS refers to a 35% wettable powder formulation designed for seed treatment.
Primary Use: Preventive control of downy mildew, late blight, and root rot in potatoes, tomatoes, and other susceptible crops. The powder is mixed with water for uniform seed coating.

9. Is Metalaxyl environmentally safe?

Answer:

Metalaxyl is stable across a range of pH conditions, reducing environmental degradation risks.
Precautions: Avoid application in waterlogged soils, as excessive moisture may affect efficacy and increase runoff potential. Follow local regulations for disposal and storage.

10. How does Metalaxyl compare to Azoxystrobin?

Answer:

Target Fungi:
- Metalaxyl: Specific to oomycetes (e.g., late blight, downy mildew).
- Azoxystrobin: Broad-spectrum, effective against ascomycetes, basidiomycetes, and some deuteromycetes.
Mode of Action:
- Metalaxyl: Curative (treats existing infections).
- Azoxystrobin: Primarily preventive (blocks spore germination).