Agriculture: Pistachio Pest Management Guidelines

Treatment Timing for Key Diseases

Note: not all indicated timings may be necessary for disease control.

Disease Dormant Bloom/terminal shoot 1/2–1 inch. (April) Succulent shoot growth/before shell lignification (May) Early Fruit development/after shell lignification (June)1 Fruit development/kernel development (July) Fruit maturation (August)2
Alternaria3 ---- ---- ----- +++ +++1 +?
Botryosphaeria4 +?5 +++6 +++6 +++ +++ +?
Botrytis ---- +++ +7 ---- ---- ----
Rating: +++ = most effective; ++ = moderately effective; + = least effective; +/? under revision; and ---- = ineffective
1 If only one application is done, the best timing is late June to early July.
2 Sprays not later than the first week in August.
3 Three applications during the season are recommended.
4 Treat 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, Luna Sensation), and make no more than two applications of a strobilurin or strobilurin-containing fungicide per season.
5 Liquid lime sulfur: some efficacy in some trials, whereas no efficacy in other trials.
6 Early season sprays timed before and/or after rains are effective timings in April and May.
7 Protect young clusters if rain and cool weather occurs.

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

Text Updated: 06/17