← Diseases

Bacterial Canker

Pseudomonas syringae pv. syringae

51 host plants

Last updated

Data Coverage 4 of 6 dimensions
Causal Agent
Host Plants
Symptoms
Management
GDD Threshold
Regional Notes

You'll spot sunken, oozing cankers on tree limbs that develop in spring, with small lesions on nearby leaves showing disease progression. This bacterial disease travels readily by rain splash and pruning wounds that provide entry points. Remove affected branches well below the visible canker margin, sterilizing all tools between cuts to prevent further spread. Avoid planting susceptible species in contaminated areas. Proper pruning technique during dry weather and tool sanitation are essential for control.

Sanitation measures have been helpful. Plant resistant cultivars. Prune affected branches well below visible symptoms and sterilize tools between cuts. Avoid pruning during wet weather, which spreads the pathogen through fresh wounds. Maintain plant vigor through proper watering and site management.

Quick Reference

Causal Agent
Pseudomonas syringae pv. syringae
Host Plants
51

Management

Vulnerability Window

Dark cankered areas on trunks and branches may develop and expand in early spring. | Leaves on girdled twigs often yellow and fall by late summer. | Do normal pruning in January or February.

Cultural Controls

  • Bacterial canker is best managed through the use of many different tactics.
  • Plant resistant cultivars and/or rootstocks.
  • For example, F12-1 Mazzard rootstock with scions from virus-tested (and found to be free of all known viruses), canker-free trees has been very useful.
  • Make buds or grafts at least 12 to 15 inches away from the trunk.
  • Mazzard seedling rootstocks have also been useful.
  • Do not interplant new trees with old trees, which are a major source of the bacteria.
Regional Notes

Bacterial canker can be the limiting factor against establishing cherry orchards in the Pacific Northwest. The combination of fall leaf-scar infection windows and spring frost damage creates high disease pressure in maritime western Washington.

Host Plants (51)

Betula lenta Sweet Birch, Cherry Birch, Black Birch Euphorbia Wood Spurge Malus robusta Cherry, Crabapple 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 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 Solanum aviculare Kangaroo Apple Vaccinium angustifolium Lowbush Blueberry Vaccinium corymbosum Highbush Blueberry Vaccinium crassifolium Creeping Blueberry, Thick-leaved Whortlberry Vaccinium macrocarpon Cranberry American Cranberry Vaccinium membranaceum Big Huckleberry, Mountain Huckleberry Thinleaf Huckleberry Vaccinium moupinense Himalayan Blueberry Vaccinium ovalifolium Oval-leaf Blueberry Vaccinium ovatum Box Huckleberry, Evergreen Huckleberry Vaccinium parvifolium Red Huckleberry, Red Whortleberry Vaccinium sikkimense Sikkim Blueberry Vaccinium uliginosum Bog Blueberry, Bog Bilberry Vaccinium vitis Vaccinium vitis