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Tomato Diseases | Bacterial Canker Fact Sheets

Bacterial Canker


Early Infections on Seedlings:

  • Originate from seed
  • Cause severe symptoms
  • Wilting and stunting
  • Open cankers on the stem
  • A thin, reddish-brown discoloration can be seen inside the stem when the stems are split open length wise

Late Infections on Plants:

  • Symptoms observed in the field
  • Browning of the outer edges of the leaflets with a thin yellow band of tissue
  • Curling upwards of leaflet edges

Late Infections on Fruit:

  • Small tan colored spots surrounded by a white halo on green or red fruit that resemble bird’s eyes-hence the term “bird’s-eye” spots

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Pictures of Bacterial Canker on tomato fruit (left) and the stem and leaves of a pepper plant (center; right).

Favorable Environmental Conditions

  • Warm temperatures (75-90 °F)
  • High moisture
  • High relative humidity

Often Confused With

Scouting Notes

  • The pathogen can be active from the time of plant emergence through to harvest.
  • Seedlings in the greenhouse should be carefully monitored for early symptoms and suspect plants should be removed from the greenhouse and submitted for plant disease diagnosis.
  • Plants in the field or greenhouse should be monitored twice a week. If disease symptoms are observed, remove the affected plant and adjacent healthy appearing plants.