Notes Nurseries have reported problems with cultivars that flower outside of the main bloom period from the bulk of their Prunus, especially those that flower very early. Susceptible cultivars that they find difficult to treat include Prunus subhirtella 'autumnalis', Pendula Plena Rosea, and Snofazam. Cultivars that seem resistant include P. sargentii 'Columnar', P. serrulata 'Mt. Fugi', and P. x yedoensis 'Akebono'.
Chemical control Only one (1) or two (2) applications during bloom are needed most years. Alternate or tank-mix products from different groups that have different modes of action. Limit the use of any one group during crop production.
- Banner MAXX at 2 to 4 fl oz/100 gal water. For non-bearing fruit trees only. Group 3 fungicide. 12-hr reentry.
- Bonide Fung-onil Multi-purpose Fungicide at 2.25 teaspoons/gal water. H
- Broadform at 4 to 6 fl oz/100 gal water. For non-bearing fruit trees only. Group 7 + 11 fungicide. 12-hr reentry.
- Chipco 26019 FLO at 1 to 2.5 quarts/100 gal water. Group 2 fungicide. 12-hr reentry.
- Compass 50 WDG at 2 to 3 oz/100 gal water. Do not use organosilicate additives. Group 11 fungicide. 12-hr reentry.
- Daconil Weather Stik at 1.4 pints/100 gal water. Treated fruit must not be eaten. Group M5 fungicide. 12-hr reentry.
- Decree 50 WDG at 0.75 to 1.5 lb/100 gal water. Group 17 fungicide. 12-hr reentry.
- Mural at 3.5 oz/100 gal water. Can be phytotoxic to certain apple and cherry cultivars. Do not apply to Yoshina variety. Group 7 + 11 fungicide. 12-hr reentery.
- Pageant at 12 oz/100 gal water. For non-bearing fruit trees only. Do not use with organosilicone-based adjuvants. Group 7 + 11 fungicide. 12-hr reentry.
- Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate for Gardens at 1 fl oz/gal water. Group 3 fungicide. H
- Thiophanate-methyl-based products. Group 1 fungicides. 12-hr reentry.
- Cleary's 3336 EG at 12 to 16 oz/100 gal water. Do not use after fruit set if applied to fruiting trees.
- OHP 6672 4.5 F at 10.75 to 20 fl oz/100 gal water. Do not use treated fruit for food.
Reference Pscheidt, J.W., and Byther, R.S. 2001. Prunus Diseases p 317-325 in Diseases of Woody Ornamentals and Trees in Nurseries, R. Jones., and M. Benson (ed.). St. Paul, MN: APS Press.