How to Manage Pests

UC Pest Management Guidelines


General Properties of Fungicides

(Reviewed 4/17, updated 4/17)

In this Guideline:

Common name (Example trade name) Chemical class Activity Mode of action (FRAC number)1 Resistance Comments
acibenzolar-S-methyl (Actigard) BTH2 systemic — (P1) low
azoxystrobin (Quadris) QoI3 contact, systemic4 single-site (11) high
boscalid (Endura) SDHI5 contact, systemic4 single-site (7) medium to high
copper inorganic contact multi-site (M1) low
cyprodinil/fludioxonil (Switch) AP/PP6 multi-site (9/12) low
dicloran (Botran) AH7 locally systemic single-site (14) high
dimethomorph (Forum) CAA8 locally systemic single-site (40) low to medium
famoxadone/cymoxanil (Tanos) QoI3/cyanoacetamide-oximes —/systemic multi-site (11/27) low
fenamidone (Reason) QoI3 systemic4 single-site (11) high
fludioxonil (Cannonball) phenylpyrrole contact few to multi-site (12) medium
fluopicolide (Presidio) benzamide locally systemic single-site (43) low
fosetyl-Al (Aliette) phosphonate systemic multi-site (33) low
iprodione (Rovral) dicarboximide locally systemic multi-site (2) medium to high toxic to honey bee larvae; do not apply during bloom.
mancozeb (Mancozeb 75WDG) dithiocarbamate contact multi-site (M3) low
mandipropamid (Revus) CAA8 systemic single-site (40) low to medium
mefenoxam (Ridomil Gold) phenylamide systemic single-site (4) high
myclobutanil (Rally) triazole systemic single-site (3) medium
penthiopyrad (Fontelis) SDHI5 contact, systemic single-site (7) medium to high
phosphorus acid (Fosphite) phosphonate systemic multi-site (33) low
quinoxyfen (Quintec) quinoline single-site (13) medium
sulfur (Microthiol Disperss) inorganic contact multi-site (M2) low toxic to predatory mites and parasites.
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Fungicides with a different group number are suitable to alternate in a resistance management program. For fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17, make no more than one application before rotating to a fungicide with a different mode-of-action group number; for fungicides with other group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode-of-action group number.
2 BTH = benzo-thiadiazole
3 QoI = quinone outside inhibitor (strobilurin)
4 Generally considered to have systemic action based on performance data but has not been proven experimentally.
5 SDHI = succinate-dehydrogenase inhibitor
6 AP/PP = anilinopyrimidine/phenylpyrrole
7 AH = aromatic hydrocarbon
8 CAA = carboxylic acid amide
No information



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Lettuce
UC ANR Publication 3450

General Information

Acknowledgment: This information was adapted from the Fungicide Resistance Action Committee website.

Top of page

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.