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.
Infection is favored by rain or dew during bloom and moderate
temperatures (about 58° to
77°F).
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/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
|
| 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. Not all registered pesticides are listed. Always read label of product being used. |
| |
| A. |
TEBUCONAZOLE |
| |
(Elite) 45WP |
4–8 oz |
12 |
0 |
| |
MODE
OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) |
| |
| B. |
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. |
| |
| C. |
PROPICONAZOLE |
| |
(Orbit, Bumper) |
4 fl oz |
see comments |
21 |
| |
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. |
| |
| D. |
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. |
| |
| E. |
THIOPHANATE METHYL |
| |
(Topsin M) 70WP |
0.5 lb/100 gal water
up to 1.5 lb/acre |
12 |
1 |
| |
MODE
OF ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1) |
| |
COMMENTS: 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. |
| |
|
| F. |
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. |
| |
| G. |
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. |
| |
| H. |
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. |
| |
| I. |
MYCLOBUTANIL |
| |
(Rally) 40WP |
2.5–6 oz |
24 |
0 |
| |
MODE
OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) |
| |
COMMENTS: Do not
apply more than 3.2 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/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. |
CAPTAN |
| |
(Various) 50WP |
4 lb |
4 days |
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. |
| |
| M. |
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. |
| |
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