Syngenta Ridomil Gold® Fungicide (Metalaxyl-M + Mancozeb)
The World’s Leading Dual-Action Fungicide for Oomycete Control
Ridomil Gold® is Syngenta's premium fungicide designed to fight "water mold" diseases like Late Blight and Downy Mildew. Unlike generic alternatives, it uses Metalaxyl-M technology, which is twice as potent as standard metalaxyl. It offers a powerful "inside-out" defense: it cures infection from within the plant while forming a protective shield on the surface.
Best For: Potatoes, Tomatoes, Grapes, Citrus, and Vegetable Nurseries.
Why Choose This Product? Key Benefits
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Hyper-Systemic Action: Absorbs into the plant within 30 minutes to 3 hours, moving upward to protect new growth that appears after spraying.
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Dual Protection: Combines Metalaxyl-M (Curative) to stop internal infection and Mancozeb (Contact) to prevent new spores from landing.
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Kick-Back Effect: Offers a curative window of 24 to 48 hours, stopping the disease even if infection has just started.
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Rainfast Reliability: The systemic component is safe from wash-off once absorbed; excellent performance even in wet weather conditions.
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Healthier Crops: By controlling stress and disease, it keeps leaves green longer (stay-green effect), resulting in better tuber bulking and fruit quality.
Technical Specifications
| Parameter | Details |
|---|---|
| Brand Name | Syngenta Ridomil Gold® |
| Technical Name | Metalaxyl-M 4% + Mancozeb 64% w/w |
| IRAC MoA Code | Group 4 (Phenylamide) + Group M3 (Multi-site) |
| Chemical Group | Phenylamide + Dithiocarbamate |
| Formulation | WG (Wettable Granules) - "Pepite" Technology |
| Toxicity Label | Blue/Green Triangle (Moderately Hazardous) |
How It Works: Mode of Action
Ridomil Gold attacks fungal pathogens using two distinct methods to prevent resistance and ensure complete control:
- Surface Shield (Mancozeb): Upon spraying, Mancozeb coats the leaves. It releases a compound that destroys fungal cell walls on contact, preventing spores from germinating.
- Internal Therapy (Metalaxyl-M): The active isomer penetrates the leaf tissue. It targets the fungus's RNA synthesis, starving the pathogen and stopping it from growing inside the plant.
- Upward Mobility: The chemical moves through the plant's water system (xylem) to protect new leaves and tips that weren't even present during the spray.
Note: This product does not move downward to roots when sprayed on leaves. For root protection, a soil drench is required.
Target Crops & Pests
| Crop | Target Pest(s) |
|---|---|
| Potatoes & Tomatoes | Late Blight (Phytophthora infestans), Early Blight |
| Grapes | Downy Mildew (Plasmopara viticola) |
| Citrus, Pepper & Nurseries | Damping Off, Foot Rot, Gummosis, Root Rot |
Dosage & Application Guide
The Golden Rule: Always follow the "Dose per Acre" for accurate results.
Dosage per Acre, Litre, & Pre-Harvest Interval (PHI)
| Crop | Dose (gm / Acre) | Water (L / Acre) | Dose (gm / Litre) | PHI (Days) |
|---|---|---|---|---|
| Potatoes / Tomatoes | 500g - 1000g | 200 - 400 L | 2.5g / L | 14 Days |
| Grapes | 500g - 1000g | 200 - 400 L | 2.5g / L | 28 - 66 Days |
| Black Pepper / Citrus (Drench) | 2 - 3 L Solution/Tree | As Needed | 2.5g / L | NA |
*PHI = Pre-Harvest Interval: The minimum number of days to wait between the last spray and harvesting.
How to Apply: Best Practices
- Timing: Apply preventively or at the very first sign of disease. Do not wait for >5% infection.
- Mixing: Do NOT mix with alkaline substances like Bordeaux mixture or Lime Sulfur, as this destroys the chemical.
- Coverage: Use high water volume and hollow cone nozzles to ensure the spray penetrates dense canopies (like potato vines).
- Safety: Always wear PPE (gloves, mask, goggles). Wash hands thoroughly after use.
Frequently Asked Questions
1. How is Ridomil Gold different from generic Metalaxyl?
Ridomil Gold contains Metalaxyl-M (Mefenoxam), which is the purified active isomer. It is 2x more potent gram-for-gram than standard generic metalaxyl and breaks down faster in soil.
2. Can I use it for Root Rot?
Yes. For root diseases like Foot Rot in pepper or Gummosis in citrus, use it as a soil drench (pour solution around the base). Foliar sprays will not cure root rot.
3. Is it rainfast?
Yes. The systemic part is absorbed quickly. Once the spray has dried on the leaf (usually within an hour), it will not wash off.
4. How many times can I spray it?
Do not spray more than 3 to 4 times per season. Rotate with other fungicides to prevent the fungus from developing resistance.
5. Can I mix it with curacron/pesticides?
Generally yes, but add Ridomil Gold to the water tank first. Never mix with strong alkalis or copper hydroxides that raise pH levels.
Safety & Disclaimer
Always read and follow the instructions on the official product label. The information provided here is for guidance only. Use personal protective equipment (PPE) during application. Pregnant women should avoid handling this product due to Mancozeb content.
