Double Spot and Gloeocercospora Leaf Spot

Dothichiza caroliniana and Gloeocercospora inconspicua

In late summer, the double spot fungus develops a secondary necrotic area around the original lesion spreading in an irregular to fan-shaped pattern. The gloeocercospora leaf spot appears on the foliage by mid-summer as large dark brown, circular to angular lesions surrounded by a dark border.

Double spot:

  • Initially is from 1/16 inch to 1/8 inch in diameter.
  • In late summer, the fungus develops a secondary necrotic area around the original lesion spreading in an irregular to fan-shaped pattern. The dark border surrounding the original lesion persists and the large necrotic area surrounds or is to one side of the original lesion.

Gloeocercospora Leaf Spot:

  • Is of minor importance as a leafspot disease.
  • It appears on the foliage by mid-summer as large dark brown, circular to angular lesions surrounded by a dark border.

Reference: Cline, W.O. “Bill.” Leaf Diseases of Blueberry. Retrieved 02 April 2010.