| Fungicide | Resistance risk (FRAC group number)1 |
Brown rot | Russet scab | Rust | |
|---|---|---|---|---|---|
| Blossom | Fruit2 | ||||
| Abound | high (11)4 | 3 | 2 | 0 | 4 |
| Adament** | medium (3/11) | 5 | 5 | ND | 5 |
| Botran | medium (14) | 3 | 3 | ND | ND |
| Bravo, Chlorothalonil, Echo, Equus8,9,10 | low (M5) | 3 | 3 | 3 | 09 |
| Bumper, Tilt2 | high (3) | 5 | 5 | 0 | 4 |
| Captan7,8,10 | low (M4) | 3 | 3 | 4 | 0 |
| Cevya | high (3) | 5 | 5 | 0 | 4 |
| Elevate2,7 | high (17)4 | 4 | 4 | ND | 0 |
| Flint Extra7 | high (11)4 | 3 | 2 | 0 | 4 |
| Fontelis | high (7) | 5 | 4 | 0 | 4 |
| Indar2 | high (3) | 5 | 5 | 0 | 4 |
| Inspire Super | high (3/9) | 5 | 5 | 0 | 4 |
| Kenja | high (7) | 5 | 4 | NL | NL |
| Luna Experience | medium (3/7) | 5 | 5 | ND | 5 |
| Luna Sensation2 | medium (7/11) | 5 | 5 | ND | ND |
| Merivon | medium (7/11) | 5 | 5 | ND | ND |
| Miravis Duo | medium (3/7) | 5 | 5 | ND | 5 |
| Ph-D, Oso | high (19) | 3 | 3 | 0 | ND |
| Pristine2 | medium (7/11) | 5 | 5 | ND | ND |
| Protocol3 | med.-high (1/3) | 5 | 5 | 0 | 5 |
| Quadris Top2 | medium (3/11) | 5 | 5 | ND | 5 |
| Quash 2 | high (3) | 5 | 5 | 0 | 4 |
| Quilt Xcel, Avaris 2XS2 | medium (3/11) | 5 | 5 | ND | 5 |
| Rally2 | high (3) | 3 | 3 | 0 | 0 |
| Rhyme | high (3) | 4 | 4 | 0 | 4 |
| Rovral/Iprodione /Nevado5 | low (2) | 4 | NR | 0 | NR |
| Rovral/Iprodione/Nevado5 mixed with oil2 | low (2) | 5 | NR | 0 | NR |
| Scala6 | high (9)3,4 | 5 | 46 | 0 | ND |
| Sulfur10 | low (M2) | 1 | 1 | 0 | 3 |
| Tebucon, Teb, Tebuconazole, Toledo2,7 | high (3) | 5 | 5 | 0 | 4 |
| Topsin-M, T-Methyl, Incognito 2,3 | high (1)4 | 4 | 1 | 0 | 0 |
| Topsin-M, T-Methyl, Incognito, and Cercobin when mixed with oil2,4 | high (1)4 | 5 | 5 | 0 | 0 |
| Vangard6 | high (9)3,4 | 5 | 46 | 0 | ND |
| Viathon | med. (3/33, P07) | 5 | 5 | 0 | 4 |
| 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, and ND = no data. NR = not registered after bloom. |
| ** Not registered, label withdrawn or inactive in California |
| 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 Fruit brown rot treatments for fungicides in FRAC groups 1,2, 3, 17, 7/11 are improved with the addition of 2% light summer oil. The oil is "light" summer oil (1-2% vol/vol). If applied in summer, fruit will lose their waxy bloom and look red. They will dry to normal color. |
| 3 Strains of Monilinia fructicola and M. laxa resistant to Topsin-M and T-Methyl have been reported in some California prune orchards. No more than two applications of Topsin-M or T-Methyl should be made each year. Resistant strains of the jacket rot fungus, Botrytis cinerea, and powdery mildew fungi have been reported in California on crops other than almond and stone fruits and may have the potential to develop in prune with overuse of fungicides with similar chemistry. Subpopulations of both Monilinia spp. Have been shown to be resistant to AP (FRAC 9) fungicides on prune in CA. |
| 4 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 numbers for subsequent applications, use labeled rates (preferably the upper range), and limit the total number of applications per season. |
| 5 Blossom blight only; not registered for use after petal fall. |
| 6 High summer temperatures and relative humidity reduce efficacy. |
| 7 Registered for use on fresh prunes only. |
| 8 Do not use in combination with or shortly before or after oil treatment. |
| 9 Do not use after jacket (shuck) split. |
| 10 Do not use sulfur, Captan, or Chlorothalonil in combination with or shortly before or after oil treatment. |
Acknowledgment: Adaskaveg et al., 2022. Fungicides, Bactericides, Biocontrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California. (PDF)