Most damage is caused by anthracnose and septoria leaf spots.
Variation occurs between cultivars and between growth flushes, with the most infection occurring on the earliest flush of growth, and little or none on the last flush of growth in late summer. Septoria leaf spot. Most commercial blueberry plantings in eastern North Carolina are affected with Gloeosporium leaf spot which can cause severe defoliation and reduction in yield. This disease can produce flecking, leaf anthracnose and stem lesions. Gloeosporium leaf spot was first described as a stem and leaf fleck disease of blueberry.