Metalaxyl 8% + Mancozeb 64% WP Fungicide Uses

Metalaxyl 8% + Mancozeb 64% WP is a broad-spectrum, dual-action fungicide combining a systemic, phenylamide component with a protectant, multi-site dithiocarbamate component, registered for use in India under the Insecticides Act, 1968, formulated as a wettable powder (WP). It is registered for the control of downy mildew, damping off, late blight, leaf blight/black shank, white rust, Alternaria blight and Phytophthora foot rot across grapes, tobacco, potato, mustard, black pepper and pearl millet. This page lists its mode of action, key benefits and the complete crop-wise recommended dosage as per the Central Insecticides Board & Registration Committee's (CIB&RC) official list of approved fungicide uses.

Which Problem Is This For? (Symptom Guide)

Not sure whether what you're seeing in the field matches this fungicide's use case? This guide helps match symptoms to this fungicide's approved crop-wise uses.

Mode of Action

This product combines two complementary modes of action. Metalaxyl (FRAC Group 4, phenylamide/acylalanine group) is a true systemic fungicide, absorbed by the roots and foliage and translocated upward through the xylem to untreated leaves and growing points; it works by inhibiting RNA polymerase I in the fungal cell, blocking ribosomal RNA synthesis and halting fungal growth. It is specifically active against oomycete pathogens (downy mildews, late blight and Phytophthora species) and gives both protective and curative activity. Mancozeb is a multi-site protectant fungicide (dithiocarbamate group, FRAC Group M03) that interferes with several enzyme systems in fungal cells simultaneously, forming a protective barrier on the plant surface that prevents spore germination before infection begins. Combining a systemic, single-site oomycete specialist with a multi-site protectant gives broader, more resilient control and helps manage the risk of resistance developing against the metalaxyl component alone.

Features & Benefits

• Systemic, root-absorbed action gives protective and curative control that reaches new growth and growing points not directly sprayed.
• Specifically effective against oomycete diseases — downy mildew, late blight and Phytophthora foot rot — that are not well controlled by many non-systemic fungicides.
• The multi-site protectant component (mancozeb) is not prone to single-site resistance, which helps slow resistance development against the metalaxyl component when used as directed.
• Versatile application — usable as a foliar spray, nursery/seedling drench, or soil drench depending on the crop and disease, as shown in the table below.

Recommended Usage of Metalaxyl 8% + Mancozeb 64% WP Fungicide

The table below gives the recommended dose and water volume per acre for each crop and target disease, converted from the official rate published in the Central Insecticides Board & Registration Committee's (CIB&RC) list of approved fungicide uses (Government of India), which is expressed per hectare (1 ha ≈ 2.47 acres). Black pepper is dosed per vine rather than per acre. The CIB&RC source table states waiting periods for this product in weeks rather than the days used for most other fungicides — these are reproduced here exactly as given. Always apply in the recommended water volume for uniform coverage, and confirm against the current product label before use.

Doses above are converted from the official rate published in the CIB&RC's list of approved fungicide uses (Government of India), which states the rate in grams formulation per hectare; converted here to a practical per-acre spray-tank quantity (1 ha ≈ 2.47 acres) and rounded. Black pepper is dosed per vine as specified in the CIB&RC source table. Always confirm the current dose on your specific product's label, and consult your local agricultural extension office if in doubt.

How to Use

1. Identify your crop and target disease from the table above, and confirm the correct dose, water volume and application method (foliar spray, nursery drench or soil drench).
2. Mix the measured quantity of Metalaxyl 8% + Mancozeb 64% WP into a small quantity of water to form a smooth paste first, then add this paste to the spray tank (or drenching container) with the remaining water and agitate thoroughly.
3. For foliar sprays, apply as a fine, uniform spray covering the entire crop canopy, including the underside of leaves where downy mildew and late blight infection typically begins.
4. For tobacco nursery and black shank use, and for black pepper foot rot, apply as a soil drench around the base of the plant/vine as specified in the table.
5. Begin treatment at the first appearance of disease symptoms, or preventively ahead of expected disease pressure during cool, humid weather.
6. Repeat sprays at 10–15 day intervals if disease pressure continues, or as advised by local agricultural extension, and rotate with fungicides from a different FRAC group to manage the risk of resistance.

Precautions & Safety

• Wear appropriate PPE — mask/respirator, gloves, goggles and full-sleeved clothing — while mixing and spraying, and avoid inhaling spray mist or dust from the wettable powder.
• Resistance to phenylamide (FRAC Group 4) fungicides, including metalaxyl, is a well-documented, real-world concern in oomycete pathogen populations worldwide because of their single-site mode of action; avoid repeated, back-to-back applications on the same crop/disease, and rotate or tank-mix with fungicides from a different resistance group as part of a resistance-management program.
• Follow the recommended dose strictly — both underdosing (poor disease control and greater risk of resistant pathogen populations developing) and overdosing reduce field performance and increase cost.
• Respect the waiting period (PHI) given in the table above and on the current product label before harvesting the treated crop.
• Store in the original, tightly closed container in a cool, dry place away from direct sunlight, food and feed, and out of reach of children and livestock.
• Wash hands, face and any exposed skin thoroughly with soap and water after handling or spraying, and change out of contaminated clothing before eating, drinking or smoking.

Brand names mentioned on this page are registered trademarks of their respective owners and are referenced here for identification purposes only; FarmMate is not affiliated with or endorsed by these brands. This page is for general information only — always consult your local agricultural extension office and confirm the current product label before use.