Introduction
Mancozeb is a multi-site inhibitor (FRAC M03) that interferes with multiple enzymatic pathways in fungi, making resistance development less likely compared with single-site fungicides. It is typically used protectively (before infection) and often tank-mixed to broaden spectrum.
History & Use
Adopted globally since the 1960s for crops including potatoes, tomatoes, grapes, bananas, cereals, and oilseeds. Its low cost and multi-site mode made it a backbone in many spray programs, particularly for late blight complexes when alternated with systemic partners.
Strengths & Limitations
- Strengths: Broad spectrum, low resistance risk, affordable, good mixing partner.
- Limitations: Strict pre-harvest intervals, repeated applications needed (contact activity), potential residues, and regulatory concerns.
Regulatory & Safety
- EU: Approval status has tightened significantly; usage is banned or severely restricted in many member states due to metabolite (ETU) concerns and potential endocrine impacts.
- Elsewhere: Still widely used with label constraints (PHIs, REIs, application limits).
Resistance Management
- Use in rotation with single-site fungicides (QoI, SDHI, triazoles) to reduce resistance selection on partners.
- Maintain protective intervals; ensure coverage (water volume, droplet size) because it’s contact-only.
Outlook
Where permitted, mancozeb will remain a cost-effective program partner. Expect continued regulatory pressure in Europe, pushing growers toward higher-priced alternatives and integrated disease forecasting to optimize timings.
