UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

Search

SKIP navigation
How to Manage Pests

Home & garden
Agriculture
Natural environments
Exotic & invasive

Weather data & products
Degree-days
Interactive tools & models

Identification Galleries

Natural enemies
Weeds

Educational Resources

Publications & more
Workshops and events
Training programs
Pesticide information

Research and IPM

Grants programs
Funded-project results

 
  Printer-friendly version

How to Manage Pests

UC Pest Management Guidelines

| More pests | More crops | About guidelines |

Pistachio

2009 Fungicide Efficacy and Treatment Timing

(Reviewed 3/09, updated 3/09)

In this Guideline:

FUNGICIDE EFFICACY FOR PISTACHIO DISEASES

Fungicide Resistance risk (FRAC#)1 Alternaria Botrytis Botryosphaeria
Abound2 high (11)3 +++ ---- +++
Benlate4 low (1) ---- +++ ++
Bravo low (M5) ++ ---- ++
Cabrio high (11)3 +++ ---- +++
Distinguish medium (9/11) ++ ++ ----
Chlorothalonil/Echo5 low (M5) NR ---- NR
Elevate high (17)3 ND ++++ ND
Gem high (11)3 +++ ---- +++
Pristine high (7/11)3 ++++6 ++++ ++++
Scala high (9)3 ++ ++ +++7
Switch high (9/12)3 +++ +++ ++
Topsin-M/T-Methyl/Thiophanate-Methyl8 high (1) ---- +++ ++
Copper low (M1) + ---- ----
Liquid lime sulfur9 low (M2) ---- ---- +/-
Rating: ++++ = excellent and consistent,  +++ = good and reliable,  ++ = moderate and variable, + = limited and/or erratic, +/- = minimal and often ineffective, ---- = ineffective, and ND = no data
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 Field resistance of Alternaria spp. to Abound and to other strobilurin fungicides (Flint and Cabrio) is widespread in pistachio orchards.
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 numbers for subsequent applications, use labeled rates (preferably the upper range), and limit the total number of applications/season.
4 Benlate label withdrawn. Previously registered for bloom treatment only.
5 Label was withdrawn for pistachio due to phytotoxicity.
6 Resistance to boscalid has been detected in high levels (80–90%) in some orchards; Pristine should not be applied if resistance to this fungicide is detected in an orchard.
7 Under low and moderate disease pressure.
8 Registered for bloom treatment only.
9 Dormant treatment only.

FUNGICIDE TREATMENT TIMING IN PISTACHIO

Disease Dormant April June3 July August
Alternaria1 ---- ---- +++ +++2 ++
Botryosphaeria3 + ++ +++ +++ ++
Botrytis ---- +++ ---- ---- ----
Rating: +++ = most effective, ++ = moderately effective, + = least effective, and ---- = ineffective.
1 Three applications during the season are recommended.
2 If only one application is done, the best timing is late June to early July.
3 Treat with Topsin-M once at bloom when the terminals on female trees are 1-2 inches long. Begin summer applications in late May or early June. Treat at 2-3 week intervals until mid-August. For resistance management, do not apply consecutive applications of any strobilurin (Abound, Flint/Gem or Cabrio) or strobilurin-containing fungicides (Pristine), and make no more than two applications of a strobilurin or strobilurin-containing fungicide per season.
Adaskaveg, J. E., B. A. Holtz, T. J. Michailides, and W. D. Gubler. 2009. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops (960 KB, PDF)

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Pistachio
UC ANR Publication 3461
General Information

Top of page

PDF: You need a PDF reader, such as Acrobat Reader version 8 or later, to view or print this PDF. If no reader is installed on your computer, you can download a free copy of Adobe Acrobat Reader.

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2009 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/r605902111.html revised: March 18, 2009. Contact webmaster.