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How to Manage Pests

UC Pest Management Guidelines

| More pests | More crops | About guidelines |

Apricot

2008 Fungicide Efficacy and Treatment Timing

(Reviewed 2/08, updated 2/08)

In this Guideline:

FUNGICIDE EFFICACY FOR APRICOT DISEASES

DO NOT USE SULFUR AT ANY TIME ON APRICOT TREES
OR USE CAPTAN PREHARVEST ON APRICOT FRUIT
Fungicide Resistance risk (FRAC#)1 Brown rot2 Jacket rot Powdery mildew2 Shot hole Eutypa
Blossom Fruit
Benlate3 high (1) ++++ ++++ ++++ +++ — —
Distinguish* medium (9/11) ++++ +++ ++++ +++ — +++
Indar/Enable4 high (3) ++++ ++++ — ND — —
Orbit (Bumper) high (3) ++++ ++++ — +++ — +/-
Pristine medium (7/11)5 ++++ ++++ +++ +++ — ++++
Rovral6 + oil7 low (2) ++++ NR ++++ — — +++
Scala high (9)5 ++++ +++8 +++9 ND — ++
Topsin-M/T-Methyl3 high (1)5 ++++ ++++ ++++ +++ +++ —
Vangard high (9)5 ++++ +++8 +++9 ND — ++
Rally high (3) +++ +++ — +++ — —
Rovral6 low (2) +++ NR +++ — — +++
Elevate high (17)5 +++ ++ +++ ++ — +
Abound high (11)5 ++ + — ND — +++
Botran medium (14) ++ ++ +++ ND — ND
Bravo/Chlorothalonil/ Echo10,11 low (M5) ++ ++ ++ — — +++
Captan11,12 low (M4) ++ —13 ++ — — +++
Gem high (11)5 ++ + — ND — +++
B-Lock — — — — — +++ —
Copper low (M1) +/- — — — — ++
Ziram low (M3) +/- — + — — ++++
Rating: ++++ = excellent and consistent, +++ = good and reliable, ++ = moderate and variable, + = limited and/or erratic, +/- = minimal and often ineffective, — = ineffective, ND = no data, and NR = not registered.
* Registration pending.
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see http://www.frac.info/). 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 Do not use fungicides with the same FRAC number and high resistance risk more than twice in one year.
3 Benlate label withdrawn. Strains of Monilinia fructicola and M. laxa resistant to Benlate, Topsin-M, and T-Methyl have been reported in some California apricot orchards. Resistant strains of the jacket rot fungus, Botrytis cinerea, have been reported in California on crops other than almond and stone fruits and may have the potential to develop in apricots with overuse of fungicides with similar chemistry.
4 Indar registered; registration for Enable pending in California.
5 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/season.
6 Blossom blight only; not registered for use after petal fall.
7 The oil is a “light” summer oil, 1-2% volume/volume.
8 High summer temperatures and relative humidity reduce efficacy.
9 Has not been tested on apricot but is effective against the jacket rot pathogens.
10 Do not use after jacket (shuck) split.
11 Do not use in combination with or shortly before or after oil treatment.
12 Causes fruit browning as a preharvest spray.
13 May cause staining on fruit.

FUNGICIDE TREATMENT TIMING IN APRICOTS

Note: Not all indicated timings may be necessary for disease control.
Disease Dormant Red bud Popcorn Full bloom Until pit
hardening		 Preharvest
1 to 3 weeks
Brown rot1 — +++ +++ +++ — +++
Jacket rot — — — +++ — ++
Powdery mildew — — — +++ +++2 —
Shot hole3 — — — ++ +++ —
Rating: +++ = most effective, ++ = moderately effective, + = least effective, and — = ineffective.
1. Begin at red bud, add one or two more sprays if weather favors disease.
2. Repeated treatment at 7- to 14-day intervals may be necessary; earlier treatments are most effective.
3. If pathogen spores were found during fall leaf monitoring, apply a shot hole fungicide during bloom, preferably at petal fall or when young leaves first appear. Re-apply when spores are found on new leaves or if heavy persistent spring rains occur. If pathogen spores were not present the previous fall, shot hole control may be delayed until spores are seen on new leaves.
Adapted from:
Adaskaveg, J. E., B. A. Holtz, T. J. Michailides, and W. D. Gubler. 2008. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops (932 KB, PDF)

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Apricot
UC ANR Publication 3433
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Statewide IPM Program, Agriculture and Natural Resources, University of California
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