FRAC Rotation Guide

Rotating fungicide modes of action (FRAC groups) prevents pathogen resistance.

Rules of thumb:

Never use the same FRAC group more than 2 applications in a row

High-resistance-risk groups (11/QoIs, 7/SDHIs): limit to 2-3 total uses per season

Multi-site products (sulfur, mancozeb, copper): low resistance risk, good rotation partners

DMIs (FRAC 3): moderate risk, backbone of many programs

Common vineyard FRAC groups:

Group 3 (DMIs): Rally, Tebuzol — systemic, moderate resistance risk

Group 7 (SDHIs): Luna, Endura — high resistance risk, limit use

Group 11 (QoIs): Sovran, Flint — high resistance risk, limit use

Group 13: Quintec — PM only, preventive, excellent rotation partner

Group M (multi-site): Sulfur, mancozeb — low resistance risk

Alternate between groups each application for best resistance management.