How to Manage Pests

UC Pest Management Guidelines


General Properties of Fungicides Used in Peaches

(Reviewed 4/10, updated 5/12, corrected 6/17)

In this Guideline:

Common name
(trade name)
Chemical class Activity Mode of action
(Group #)1
Resistance potential Comments
azoxystrobin (Abound) Qol2 contact, systemic single-site (11) high
bordeaux inorganic contact multi-site (M1) low  
captan phthalamide contact multi-site (M4) low highly toxic to honey bee larvae
chlorothalonil (Bravo, etc.) chloronitrile contact multi-site (M5) low  
copper inorganic contact multi-site (M1) low  
cyprodinil (Vangard) anilinopyrimidine mostly contact single-site (9) high  
dicloran (Botran) aromatic hydrocarbon contact, systemic (local) single-site (14) medium  
dodine (Syllit) guanidine systemic (local) unknown (U12) medium  
fenbuconazole (Indar) DMI3-triazole systemic (local) single-site (3) high  
fenhexamid (Elevate) hydroxyanilide contact single-site (17) high  
fosetyl-al (Aliette) ethyl phosphonate systemic unknown (33) low  
iprodione (Rovral, etc.) dicarboximide systemic (local) single-site? (2) medium toxic to honey bee larvae
mefenoxam (Ridomil Gold) acylalanine contact, systemic single-site (4) high  
metconazole (Quash) DMI3-triazole systemic (local) single-site (3) high  
myclobutanil (Rally) DMI3-triazole systemic (local) single-site (3) high  
propiconazole (Bumper/Tilt) DMI3-triazole systemic (local) single-site (3) high  
pyraclostrobin/boscalid (Pristine) Qol2/SDHI5 contact, systemic single-site/single-site (11/7) high  
pyrimethanil (Scala) anilinopyrimidine mostly contact single-site (9) high  
quinoxyfen (Quintec) quinoline contact single-site (13) medium  
sulfur inorganic contact multi-site (M2) low highly toxic to native strains of western predatory mite (Galendro–mus occidentalis) and to parasites
tebuconazole (Elite) DMI3-triazole systemic (local) single-site (3) high  
tebuconazole/trifloxystrobin (Adament) DMI3-triazole/Qol2 systemic single-site/ single-site (3/11) medium  
thiophanate-methyl (Topsin, etc.) MBC6 systemic (local) single-site (1) very high  
thiram (Thiram Granuflo) carbamate (DMDC4) contact multi-site (M3) low  
trifloxystrobin (Gem) Qol2 contact, systemic7 single-site (11) high8  
ziram carbamate (DMDC4) contact multi-site (M3) low  
= no information
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1, 4, 9, 11, or 17 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 Qol = quinone outside inhibitor (strobilurin)
3 DMI = demethylation (sterol) inhibitor
4 DMDC = dimethyl dithiocarbamate
5 SDHI = Succinate dehydrogenase inhibitor
6 MBC = Methyl benzimidazole carbamate
7 Fungicide is generally considered to have systemic action based on performance data, but this characteristic has not been necessarily proven experimentally using more rigorous assays (e.g. radioactively labeled compounds).
8 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 numbers. Use labeled rates (preferably the upper range) of the single-site fungicides, and limit the total number of applications/season.



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Peach
UC ANR Publication 3454

General Information

Acknowledgment: Adaskaveg et al., 2017. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops. (PDF)

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