Septoria Leaf Spot of Blueberry and Grape


Septoria Leaf Spot

The septoria leaf spot fungus overwinters
in infected leaves on the ground
and in stem lesions.
Photo courtesy of NCSU Cooperative
Extension Service.



  • Small to medium brown leaf spots with purplish margins.
  • Lesions on succulent green stems.
  • Premature defoliation of bushes.

Disease cycle:

  • Leaf spot infections occur on immature leaves.
  • Symptoms may take a month or more to become visible.
  • Most leaf spots begin to appear in mid- to late season and are favored by wet weather.
  • The causal fungi all produce rain-splash-dispersed spores and overwinter in infected tissues.

Disease management:

  • Plant resistant cultivars.
  • Limit overhead irrigation.
  • Reduce humidity in the canopy.
  • Apply effective fungicides before the onset of symptoms.