| Common name (Example trade name) | Chemical class | Activity | Mode-of-action group number1 | Resistance potential |
|---|---|---|---|---|
| azoxystrobin (Quadris) | QoI2 | systemic | 11 (single-site) | high |
| carboxin (Vitavax-34)3 | carboxamide | systemic (local) | 7 (multi-site) | medium to high |
| carboxin/thiram (Vitavax-200)3 | carboxamide/ dithiocarbamates | systemic (local)/— | 7/M03 (multi-site) | medium to high |
| difenoconazole/mefenoxam (Dividend Extreme) | DMI4-triazole/acylalanines | systemic (local) | 3/4 (single-site) | high |
| mancozeb (Dithane M45) | carbamate (EBDC)5 | contact | M03 (multi-site) | low |
| propiconazole (Tilt) | DMI4-triazole | systemic (local) | 3 (single-site) | high |
| propiconazole/ trifloxystrobin (Stratego) | DMI4-triazole/QoI2 | systemic | 3/11 (single- or multi-site) | high |
| pyraclostrobin (Headline) | QoI2 | systemic | 11 (single-site) | high |
| 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 a fungicide with a different mode-of-action group number. |
| 2 | QoI = quinone outside inhibitor (strobilurin) |
| 3 | This product is not registered for use in California, but seed treated in and obtained from another state can be legally used in California even for a pesticide not registered on small grains in California. |
| 4 | DMI = demethylation (sterol) inhibitor |
| 5 | EBDC = ethylene bisdithiocarbamate |
Acknowledgment: This information was adapted from the Fungicide Resistance Action Committee website.
Text Updated: 07/25