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Raspberry leaf spot (Sphaerulina rubi), also known as Sphaerulina leaf spot, is a fungal disease that frequently affects raspberry. Symptoms include leaf spots that can lead to defoliation. Spots are small, circular to angular, and develop on surfaces of new leaves. Spots remain small, turn gray to white with age, and centers drop out to cause a shot-hole effect. Cane lesions look similar to the leaf spots; they develop on bases of young canes. The fungus overwinters in fallen leaves or in cankers. Young, expanding leaves and canes are susceptible to spring infections. This disease is easily confused with Septoria leaf spot, which is specific to blackberry.

Sphaerulina leaf spot.

(Photo: Elizabeth Bush, Virginia Tech., Bugwood.org)

Close-up of angular spotting.

(Photo: Elizabeth Bush, Virginia Tech., Bugwood.org)

Management:

• Increase air circulation to encourage drying of plant tissues (pruning, thinning, spacing, and managing weeds).
• Practice proper sanitation (remove floricanes after harvest, remove all diseased canes).
• Apply fungicides.

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