UC IPM: UC Management Guidelines for Peach Leaf Curl on Nectarine

UC Pest Management Guidelines

Leaf curl symptoms on leaves and young twigs.

Nectarine

Peach Leaf Curl

Pathogen: Taphrina deformans

(Reviewed 6/06, updated 9/06)

In this Guideline:

Symptoms
Comments on the disease
Management

SYMPTOMS

Leaves produced in spring are thickened, curled, and colored red or yellow instead of normal green. Severely affected shoots die. Irregular, reddish lesions are sometimes seen on fruit. Badly diseased leaves fall by early summer, and repeated infections debilitate trees and kill branches.

COMMENTS ON THE DISEASE

Taphrina deformans survives on tree surfaces and buds and is favored by wet weather during spring.

Peach leaf curl can be a serious problem, especially on many of the new low-chilling varieties and when spring weather is unusually wet. This disease is usually kept under control with a dormant fungicide application.

Organically Acceptable Methods
Spraying with Bordeaux mixture or copper is acceptable in an organically certified crop.

Chemical Control
One application in fall after leaf fall is sufficient except in areas of high rainfall or where leaf curl has become an increasing problem. In such cases, an added application in late winter before bud swell is recommended.

Common name

(trade name)

Amount to Use

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental impact.

ZIRAM 76DF

8–10 lb/acre

MODE OF ACTION: A multi-site contact (Group M3)¹ dithio-carbamate fungicide.

BORDEAUX MIXTURE#

10:10:100

Label rates

MODE OF ACTION: A multi-site contact (Group M1)¹ inorganic fungicide.

COMMENTS: Not all copper compounds are approved for use in organic production so be sure to check individual products.

FIXED COPPER#

(various products)

Label rates

MODE OF ACTION: A multi-site contact (Group M1)¹ inorganic fungicide.

COMMENTS: Not all copper compounds are approved for use in organic production so be sure to check individual products.

CHLOROTHALONIL

(Echo 720)

3.125–4.125 pt/acre

(Bravo Ultrex DF)

2.8-3.8 lb/acre

(Bravo Weather Stik)

3.125–4.125 pt/acre

MODE OF ACTION: A multi-site contact (Group M5)¹ chloronitrile fungicide.

COMMENTS: Do not use with or closely following oil sprays.

+	Preharvest interval. Do not apply within this many days of harvest.
#	Acceptable for use on organically grown produce.
¹	Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Fungicides with a different Group number are suitable to alternate in a resistance management program. For more information, see http://www.frac.info/.

More information on nectarine fungicides

UC IPM Pest Management Guidelines: Nectarine
UC ANR Publication 3451
Diseases
W. D. Gubler, Plant Pathology, UC Davis
J. E. Adaskaveg, Plant Pathology, UC Riverside
Acknowledgment for contributions to the diseases section:
B. L. Teviotdale, Kearney Agricultural Center, Parlier

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