Brown Rot

Monilinia fructicola and M

37 host plants

Last updated

Data Maturity Baseline

This profile contains verified disease data from extension databases. Regional field notes and expert review are in progress.

During bloom, look for wilted, blighted flowers that turn brown and mummify on the branch; this blossom blight phase is your first sign of brown rot on stone fruits and ornamental relatives in the region. The disease spreads to young twigs and fruit later in the season, especially during warm, wet weather when temperatures sit between 68 and 77 degrees Fahrenheit. Mummified fruit left on trees or fallen to the ground overwinters and serves as a disease reservoir for the next season.

Brown rot spreads fast in our spring weather, so focus on preventing conditions that favor it: good air circulation is your primary weapon. Space trees wide enough to dry quickly after rain, prune to remove dense growth, and avoid overhead watering that keeps foliage wet. Remove mummified fruit from trees and rake up fallen fruit promptly. Prune out infected twigs in late spring or summer while you can still see the canker; waiting until dormancy makes infected tissue harder to spot.

Quick Reference

Causal Agent
Monilinia fructicola and M
Host Plants
37
Spread
Wind-dispersed conidia from infected flowers and twigs; ascospores from apoth...
Favorable Conditions
Warm, wet conditions during bloom period; optimum 68-77°F (20-25°C) with free...

Management

Vulnerability Window

Full bloom period (primary risk window); early fruit development; post-harvest storage in cool, moist conditions. Spring weather during bud break through full bloom critical for disease incidence.

What Triggers Infection

Warm, wet conditions during bloom period; optimum 68-77°F (20-25°C) with free moisture (rain, irrigation, dew). Conidia and ascospores germinate readily on wet flower tissue and new shoots. Infection requires free water or high humidity during bloom. Cold springs delay apothecial development; warm, wet springs accelerate disease. # Source: PNW Plant Disease Management Handbook

Cultural Controls

  • Rake and destroy infected leaves and mummified fruit to reduce spread of disease.
  • Remove mummified fruit remaining on the tree, as well.
  • Prune out infected twigs in late spring or summer.
  • Do not wait until the dormant season, when infected twigs are difficult to distinguish.
  • Space plantings and prune to provide good air circulation.
  • This will reduce the moist conditions favoring disease.

Host Plants (37)

Cydonia oblonga Quince Prunus americana Wild Plum American (Red) Plum August Plum, Goose Plum Prunus armeniaca Apricot Prunus avium Sweet Cherry Prunus besseyi Sand Cherry, Western Sand Cherry Prunus blireiana Blireiana Plum Prunus caroliniana Carolina Cherrylaurel American Cherrylaurel Prunus cascade Prunus cascade Prunus cerasifera Cherry, Plum Prunus cistena Purpleleaf Sandcherry Redleaf Sandcherry Cistena Sandcherry Cistena Plum Prunus dream Prunus dream Prunus emarginata Bitter Cherry, Wild Cherry, Quinine Cherry Prunus first Prunus first Prunus fruticosa Steppe Cherry, European Dwarf Ground Cherry, Mongolian Cherry Prunus glandulosa Dwarf Flowering Almond Prunus ilicifolia Hollyleaf Cherry, Holly-leaved Cherry Prunus laurocerasus Cherry, Laurel Prunus lusitanica Portugal Laurel Prunus maackii Amur Chokecherry Amur Cherry, Manchurian Cherry Prunus mume Japanese Apricotc Japanese Flowering Apricot Japanese Flowering Plum Prunus newport Newport Flowering Plum Prunus okame Okame Flowering Cherry Prunus padus European Birdcherry Common Birdcherry Prunus prostrata Rock Cherry, Mountain Cherry Prunus sargentii Sargent Cherry, Sargent's Cherry Prunus serotina Black Cherry, Rum Cherry Prunus serrula Birchbark Cherry, Paperbark Cherry, Tibetan Cherry Prunus serrulata Japanese Flowering Cherry Prunus snow Prunus snow Prunus subcordata Klamath Plum, Sierra Plum, Pacific Plum Prunus subhirtella Higan Cherry Prunus subhirtella var. autumnalis Autumn Flowering Higan Cherry Prunus tai Prunus tai Prunus virginiana Prunus virginiana Prunus virginiana var. demissa Western Chokecherry Prunus virginiana var. virginiana Common Chokecherry, Eastern Chokecherry Prunus yedoensis Yoshino Cherry, Somei-yoshino Cherry, Tokyo Cherry