Fungicide Resistance: FRAC Groups Explained

What Are FRAC Groups?

The Fungicide Resistance Action Committee (FRAC) classifies fungicides by their mode of action into numbered groups. Products in the same FRAC group have the same target site in the fungus — meaning if resistance develops to one product, all products in that group lose effectiveness.

Key FRAC Groups in Our Range

Why Rotate FRAC Groups

Applying the same FRAC group repeatedly selects for resistant fungal mutants. Within 3–5 seasons of exclusive use, some fungicides lose significant efficacy.

Rotation strategy:

1. •Start season with a multi-site contact fungicide (FRAC M3 — Mancozeb)
2. •Switch to a systemic single-site fungicide (FRAC 3 — Tebuconazole) at first disease sign
3. •Alternate between contact and systemic applications
4. •Never apply the same single-site fungicide more than 2 consecutive times

Tank Mixing for Resistance Management

Mixing a contact fungicide (Mancozeb) with a systemic fungicide (Tebuconazole) in a single spray provides:

• •Immediate protection from the contact component
• •Curative activity from the systemic
• •Resistance management through dual modes of action