| Common name (Example trade name) |
Class | Group (FRAC) number1 | Activity | Mode of action | Resistance potential | Comments |
|---|---|---|---|---|---|---|
| azoxystrobin (Abound, Quadris Top) | Qol4 | 11 | contact, systemic2 |
single-site | high7 | Resistance in Botrytis and Colletotrichum documented |
| captan | phthalimide | M4 | contact | multi-site | very low to low | toxic to honey bee larvae |
| chlorothalonil (Bravo) | chloronitrile | M5 | contact | multi-site | low | |
| cyflufenamid (Torino) | phenyl-acetamide | U6 | contact | — | high | |
| cyprodinil/fludioxonil (Switch) | anilinopyrimidine/phenylpyrrole | 9/12 | contact/slightly systemic | single-site/single-site | medium to high | |
| fenhexamid (Elevate) | hydroxyanilide | 17 | contact | single-site | high7 | Resistance in Botrytis documented |
| fluopyram (Luna Privilege) | SDHI5 | 7 | contact | single-site | high7 | |
| fluopyram/trifloxystrobin (Luna Sensation) | SDHI5/Qol4 | 7/11 | contact, systemic | single-site/single-site | medium to high | |
| fosetyl-al (Aliette) | phosphonates | P07, 33 | systemic | unknown | low | |
| insecticidal soap (M-pede) | inorganic salt | — | contact | — | low to medium | |
| iprodione (Rovral) | dicarboximide | 2 | systemic (local) | single-site? | low to medium | toxic to honey bee larvae |
| isofetamid (Kenja) | SDHI5 | 7 | contact | single-site | high7 | |
| mefenoxam (Ridomil Gold) | phenylamide | 4 | contact, systemic | single-site | high7 | |
| myclobutanil (Rally) | DMI3-triazole | 3 | systemic (local)2 | single-site | high | |
| penthiopyrad (Fontelis) | SDHI5 | 7 | contact | single-site | high7 | |
| phosphorous acid (Fosphite) | phosphonates | P07, 33 | systemic | unknown (multi-site?) | medium | |
| pyraclostrobin/boscalid (Pristine) | Qol4/SDHI5 | 11/7 | contact, systemic2 | single-site/single-site | medium to high | Resistance in Botrytis documented |
| pyraclostrobin/fluxapyroxad (Merivon) | Qol4/SDHI5 | 11/7 | contact, systemic2 | single-site/single-site | medium to high | |
| quinoxyfen (Quintec) | quinolines | 13 | contact | single-site | medium to high | |
| sulfur | inorganic | M2 | contact | multi-site | low | |
| tetraconazole (Mettle) | DMI3-triazole | 3 | systemic (local)2 | single-site | high | |
| thiophanate-methyl (Topsin-M) | MBC6 | 1 | systemic (local) | single-site | very high7 | Resistance in Botrytis documented |
| thiram | dithiocarbamates | M3 | contact | multi-site | low | |
| triflumizole (Procure) | DMI3-triazole | 3 | systemic (local)2 | single-site | high7 |
| 1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of action. Fungicides with different group numbers are suitable to alternate in a resistance management program. In California, make no more than one application of a fungicide with a mode-of-action group number associated with high resistance risk before rotating to a fungicide with a different mode-of-action group number; for other fungicides, make no more than two consecutive applications before rotating to fungicide with a different mode-of-action group number. |
| 2 Generally considered to have systemic action based on performance data but has not been proven experimentally. |
| 3 DMI = demethylation (sterol) inhibitor |
| 4 Qol = quinone outside inhibitor (strobilurin) |
| 5 SDHI = succinate dehydrogenase inhibitor |
| 6 MBC = methyl benzimidazole carbamate |
| 7 Resistance has been found in California for certain fungicides with a single-site mode of action. To reduce the risk of resistance development, take the mode of action into account when choosing a fungicide. At the beginning of a treatment program, use a fungicide with a multi-site mode of action; for subsequent applications rotate or mix fungicides with different mode of action FRAC group numbers. Use labeled rates (preferably the upper range) of the single-site fungicides, and limit the total number of applications per season. |
Acknowledgment: Adaskaveg et al., 2022. Fungicides, Bactericides, Biocolntrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California. (PDF)