How to Manage Pests

UC Pest Management Guidelines

Cherry

Brown Rot Blossom and Twig Blight

Pathogens: Monilinia fructicola, Monilinia laxa

(Reviewed 11/09, updated 3/13)

In this Guideline:


Symptoms and Signs

Brown rot infection occurs through blossom parts and progresses into the twig, killing blossoms, spurs, and associated leaves. Small cankers on twigs form below infected spurs; gum may be present at the base of flowers and dead flowers remain on the tree. Beige-colored spore masses develop on diseased flowers under high humidity.

Comments on the Disease

Infection is favored by rain or dew during bloom and moderate temperatures (about 58°to 77°F).

Management

Cherries are the least susceptible stone fruit to this disease and preventive sprays may not be needed unless the weather is favorable for infection or the orchard has a history of this disease. One and sometimes two applications may be necessary and are most effective when made sufficiently in advance of rain so that the spray has time to dry. Start treatment at the popcorn stage of bloom. To provide adequate continuing protection, spray every 14 days until bloom is completed. When continued heavy rainfall is occurring or other conditions are conducive to infection, shorten this interval to 10 days. Aerial applications are generally not as effective as properly applied ground sprays but may be necessary when the orchard floor is too wet.

Common name Amount per acre R.E.I.‡ P.H.I.‡
(trade name)   (hours) (days)

  Calculate impact of pesticide on air quality
 
When choosing a pesticide, consider its usefulness in an IPM program by reviewing the pesticide's properties, efficacy, application timing, and information relating to resistance management, honey bees (PDF) and environmental impact. Not all registered pesticides are listed. Always read the label of the product being listed.
 
A. AZOXYSTROBIN+DIFENCONAZOLE
  (Quadris Top) 12-14 fl oz per
100 gal water
12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) and Demethylation inhibitor (3)
  COMMENTS: Resistance to FRAC 3 and FRAC 11 group fungicides is possible in fungal populations. Use only when alternating with a fungicide that has at least one different FRAC Group number.
 
B. AZOXYSTROBIN+PROPICONAZOLE
  (QuiltXcel) 14 fl oz per
100 gal water
12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) and Demethylation inhibitor (3)
  COMMENTS: Resistance to FRAC 3 and FRAC 11 group fungicides is possible in fungal populations. Use only when alternating with a fungicide that has at least one different FRAC Group number.
 
C. TEBUCONAZOLE+TRIFLOXYSTROBIN
  (Adament 50WG) 4-8 fl oz per
100 gal water
12 1
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) and Demethylation inhibitor (3)
  COMMENTS: Resistance to FRAC 3 and FRAC 11 group fungicides is possible in fungal populations. Use only when alternating with a fungicide that has at least one different FRAC Group number.
 
D. FLUOPYRAM+TRIFLOXYSTROBIN
  (Luna Sensation) 5.0-5.6 fl oz per
100 gal water
12 1
  MODE-OF-ACTION GROUP NAME (NUMBER1): Succinate dehydrogenase inhibitors (7) and Quinone outside inhibitor (11)
  COMMENTS: Resistance to FRAC 7 and FRAC 11 group fungicides is possible in fungal populations. Use only when alternating with a fungicide that has at least one different FRAC Group number.
 
E. PENTHIOPYRAD
  (Fontelis) 14-20 fl oz 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Succinate dehydrogenase inhibitors (7)
  COMMENTS: Resistance to FRAC 7 group fungicides is possible in fungal populations. Use only when alternating with a fungicide that has a different FRAC Group number.
 
F. TEBUCONAZOLE
  (Elite 45WP) 4-8 oz 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
 
G. PROPICONAZOLE
  (Orbit, Bumper) 4 fl oz See label See label
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: REI for Bumper is 24 hours and for Orbit, 12 hours. Do not apply more than 8 fl oz/acre/crop. See label for maximum amounts allowed per season.
 
H. FENBUCONAZOLE
  (Indar 75WSP) 2 oz 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: Apply in a minimum of 50 gal water/acre. A protectant fungicide. Begin applications before infections occur if conditions are conducive to disease development. Do not apply more than 1 lb of formulated product/acre/season.
 
I. MYCLOBUTANIL
  (Rally 40WSP) 2.5-6 oz 24 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: Do not apply more than 3.25 lb product/acre/season. More effective when applied as a concentrate (80-100 gal/acre) than as a dilute spray.
 
J. TRIFLUMIZOLE
  (Procure 50W) 10-16 oz 12 1
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: Do not apply more than 96 oz/acre/season.
 
K. FENARIMOL
  (Rubigan EC) 6-12 oz per
200 gal water
12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: Do not apply more than 48 oz before harvest.
 
L. METCONAZOLE
  (Quash) 4 fl oz 12 14
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
  COMMENTS: Resistance to FRAC 3 group fungicide is low but possible in Monilinia populations. Use only when alternating with a fungicide that has a different FRAC Group number.
 
M. IPRODIONE
  (Rovral 4) 1-2 pt 24
  MODE-OF-ACTION GROUP NAME (NUMBER1): Dicarboximide (2)
  COMMENTS: Addition of a narrow range oil (superior, supreme) at 1-2% increases the effectiveness of this material. Do not apply after petal fall.
 
N. FENHEXAMID
  (Elevate 50WDG) 1-1.5 lb 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Hydroxyanilide (17)
  COMMENTS: Do not apply more than 6 lb/acre/season or make more than 2 consecutive applications with this product.
 
O. THIOPHANATE METHYL
  (Topsin M 70WP) 1.0-1.5 per
100 gal water
12 1
  MODE-OF-ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1)
  COMMENTS: Recommended rate is 1.5 lb/A. Use only once a year. Resistance to thiophanate methyl is common in populations of Monilinia fructicola and Botrytis cinerea in California cherry orchards. If resistance has occurred in the orchard, do not use this product. Otherwise, use only in combination or in an alternating application program with a fungicide that has a different Group number.
 
P. PYRACLOSTROBIN+BOSCALID
  (Pristine) 10.5-14.5 oz 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11)
  COMMENTS: To reduce the potential for the development of resistance, do not make more than a total of five applications/season of Group 7 or 11 fungicides.
 
Q. AZOXYSTROBIN
  (Abound) 12.3-15.4 fl oz 4 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11)
  COMMENTS: Do not apply more than 1 lb a.i./acre/season.
 
R. CAPTAN
  (Various 50WP) 4 lb 24 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M4)
  COMMENTS: Do not apply in combination with, immediately before, or closely following oil sprays.
 
S. CHLOROTHALONIL
  (Echo 720) 3.125-4.125 pt 12 0
  (Bravo Ultrex) 2.8-3.8 lb 12 0
  (Bravo Weather Stik) 3.125-4.125 pt 12 0
  MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M5)
  COMMENTS: May cause an allergic skin reaction in some people. Do not use with or closely following oil sprays. Do not apply more than 20.5 pt Bravo Weather Stik/acre/season. Do not apply more than 18.8 lb Bravo Ultrex/acre/season.
 
Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
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.

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Cherry
UC ANR Publication 3440

Diseases

  • J. E. Adaskaveg, Plant Pathology, UC Riverside
  • J. L. Caprile, UC Cooperative Extension, Contra Costa County
Acknowledgment for contributions to Diseases:
  • W. D. Gubler, Plant Pathology, UC Davis
  • B. L. Teviotdale, Kearney Agricultural Center, Parlier

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