Symptoms and Signs
Jacket rot occurs during the jacket stage when remnants of the flower parts are still attached to the fruit. The disease causes a brown discoloration on the fruit under the jacket. The young fruit withers and falls off the tree within a few weeks.
Comments on the Disease
Development of jacket rot is favored by wet weather during the bloom and jacket stage. Frost can exacerbate the problem.
Management
One fungicide application at full bloom is generally effective. Fungicides applied during the jacket stage are generally much less effective. Treat at full bloom or shortly thereafter but before petal fall. The final bloom spray for blossom brown rot often provides jacket rot control if the appropriate fungicides (iprodione, thiophanate-methyl, pyraclostrobin/boscalid, cyprodinil, etc.) are chosen.
| Common name | Amount per acre** | REI‡ | PHI‡ | |
|---|---|---|---|---|
| (Example trade name) | (hours) | (days) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least likely to cause resistance are at the top of the table. When choosing a pesticide, consider information relating to the pesticide's properties and application timing, honey bees, and environmental impact. Always read the label of the product being used. | ||||
| A. | TEBUCONAZOLE/TRIFLOXYSTROBIN | |||
| (Adamant 50WG) | 4–8 oz | 5 days | 1 | |
| MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) and Quinone outside inhibitor (11) | ||||
| B. | PROPICONAZOLE | |||
| (Bumper, Tilt) | 4 fl oz | 12 | 0 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) | ||||
| C. | TEBUCONAZOLE | |||
| (Elite 45WP) | 4–8 oz | 120 (5 days) | 0 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) | ||||
| COMMENTS: Do not apply more than 3 lb/acre per season. | ||||
| D. | FENBUCONAZOLE | |||
| (Indar 2F) | 6 fl oz | 12 | 0 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) | ||||
| COMMENTS: Do not apply more than 1 lb/acre per season. | ||||
| E. | IPRODIONE | |||
| (Rovral 4) | 1–2 pt | 24 | See comments | |
| 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 use after petal fall. | ||||
| F. | THIOPHANATE-METHYL | |||
| (Topsin-M 70 WP) | 1 1/2 lb | 12 | 1 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1) | ||||
| COMMENTS: A benzimidazole fungicide. Apply thiophanate methyl in combination with another fungicide of different chemistry. | ||||
| G. | PYRACLOSTROBIN/BOSCALID | |||
| (Pristine) | 10.5–14.5 oz | 12 | 0 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) and Carboxamide (7) | ||||
| COMMENTS: A strobilurin and carboxyanilide fungicide. To reduce the potential for the development of resistance, do not make more than five applications per season of Pristine or other strobilurin or carboxyanilide fungicides. | ||||
| H. | CYPRODINIL | |||
| (Vangard WG) | 5–10 oz | 12 | 2 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Anilinopyrimidine (9) | ||||
| COMMENTS: An anilinopyrimidine fungicide. | ||||
| I. | FENHEXAMID | |||
| (Elevate 50WDG) | 1–1.5 lb | 12 | 0 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Hydroxyanilide (17) | ||||
| COMMENTS: A hydroxyanilide fungicide. Do not apply more than 6 lb/acre per season and avoid making more than 2 consecutive applications with this material. | ||||
| J. | DICLORAN | |||
| (Botran 75-W) | 2 lb | 12 | 10 | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Aromatic hydrocarbon (14) | ||||
| COMMENTS: An aromatic hydrocarbon fungicide. | ||||
| K. | CHLOROTHALONIL | |||
| (Echo 720) | 3.125–4.125 pt | 12 | See comments | |
| (Bravo Ultrex) | 2.8–3.8 lb | 12 | See comments | |
| (Bravo Weather Stik) | 3 1/8–4 1/8 pt | 12 | See comments | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M5) | ||||
| COMMENTS: An aromatic nitrile fungicide. May cause an allergic skin reaction in some people. Do not use with or closely following oil sprays. Do not apply after jacket (shuck) split. | ||||
| L. | CAPTAN | |||
| (Captan 50WP) | 4–8 lb | 24 | See comments | |
| MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M4) | ||||
| COMMENTS: A phthalamide fungicide. Do not apply in combination with, immediately before, or closely following oil sprays. Do not apply after 75% petal fall. | ||||
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) 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 a fungicide with a different mode of action Group number. |