| Fungicide*** | Resistance risk (FRAC group number)1 |
Scab | Powdery mildew | |
|---|---|---|---|---|
| protectant | eradicant | |||
| Adament** | medium (3/11)3 | 5 | 5 | 5 |
| Aprovia | high (7) | 5 | 3 | 4 |
| Axios | high (52) | 4 | 4 | 5 |
| Captan5 | low (M 04) | 4 | 0 | 0 |
| Cevya | high (3) | 4 | 3 | 5 |
| Copper5 | low (M 01) | 36 | 0 | 0 |
| Dithane, Manzate, Penncozeb5 |
low (M 03) | 4 | 0 | 0 |
| Flint Extra2 | high (11)3 | 5 | 5 | 5 |
| Fontelis | high (7) | 5 | 3 | 3 |
| Inspire Super | medium (3/9) | 5 | 5 | 5 |
| Kenja | high (7) | 5 | 3 | 4 |
| Lime sulfur5,7 | low (M 02) | 3 | 57 | 48 |
| Luna Sensation | medium (7/11) | 5 | 3 | 5 |
| Merivon | medium (7/11) | 5 | 3 | 5 |
| Ph-D, Oso | high (19) | 3 | 0 | 4 |
| Pristine | medium (7/11) | 5 | 0 | 4 |
| Procure4 | high (3) | 5 | 5 | 5 |
| Regev | medium (3/BM 01) | 5 | 5 | 5 |
| Rhyme | high (3) | 5 | 3 | 5 |
| Rubigan**, Vintage**,4 | high (3) | 5 | 5 | 4 |
| Scala | high (9)3 | 4 | 4 | 2 |
| Sovran | high (11)3 | 4 | 4 | 4 |
| Sulfur6 | low (M 02) | 3 | 0 | 5 |
| Syllit | medium (U12) | 4 | 4 | 0 |
| Tebucon, Toledo, etc. | high (3) | 4 | 4 | 4 |
| Tesaris, Sercadis** | high (7) | 5 | 3 | 4 |
| Topsin-M, T-Methyl, Incognito, Cercobin** | high (1)3 | 4 | 4 | 4 |
| Torino | high (U 6) | NL | NL | ND |
| Vangard | high (9)3 | 4 | 4 | 4 |
| Ziram5 | low (M 03) | 3 | 0 | 0 |
Rating: 5 = excellent and consistent, 4 = good and reliable, 3 = moderate and variable, 2 = limited and/or erratic,
1 = minimal and often ineffective, 0 = ineffective, NL = not on label, ND = no data
| ** | Not registered, label withdrawn or inactive in California. |
| *** | Postharvest fruit registrations in California include: Academy, Alumni/TBZ, BioSpectra/CeraFruta, Penbotec/Pyrimethanil and Scholar/FDL. |
| 1 | Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of action (for more information, see www.frac.info). 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 | High resistance potential to trifloxystrobin for apple and pear scab pathogen populations. |
| 3 | To reduce the risk of resistance development, start treatments with a fungicide with a multi-site mode of action; rotate or mix fungicides with different mode-of-action FRAC group numbers for subsequent applications, use labeled rates (preferably the upper range), and limit the total number of applications per season. |
| 4 | Use only before white bud and after full bloom. |
| 5 | These materials show some efficacy and should be used in mixtures with antibiotics as a component of resistance management programs. |
| 6 | Though copper may be effective for scab and blight control under low disease pressure, copper products may cause fruit scarring or russeting. |
| 7 | "Burns out" scab twig lesions when applied at delayed dormant and disrupts pseudothecial (or ascostroma) development when applied to leaves in fall. CAUTION: Lime Sulfur is incompatible with most other pesticides when used after budbreak. Check before use. Sulfur products are also used to thin flowers because of their phytotoxicity and indirectly control fire blight. |
| 8 | In-season application eradicates powdery mildew. |
Acknowledgment: Adaskaveg et al., 2025. Fungicides, Bactericides, Biocontrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California.