Septoria leaf spot of strawberry

Septoria leaf spot, caused by the fungus Septogloeum potentillae, is a common foliar disease affecting strawberry crops worldwide. It is characterized as a fungal spot disease that specifically targets the leaves, impacting the plant's overall health and vigor throughout the growing season.

The primary host for this pathogen is the cultivated strawberry. While the disease primarily impacts leaf tissue, severe infections can occasionally appear on the petioles or calyxes. Susceptibility varies among cultivars, with some varieties showing higher resistance to this specific pathogen.

Symptoms typically begin as small, round, reddish-purple spots on the upper leaf surface. As the disease progresses, the center of these spots turns necrotic and becomes white or gray. The presence of tiny black dots, known as pycnidia, within the white center is a definitive diagnostic feature of this fungus.

The development of the disease is highly dependent on environmental conditions, particularly high humidity and wet foliage. The pathogen survives in infected plant debris left on the field, with spores spread primarily through rain splashing and wind, which infect new growth during periods of prolonged dampness.

The damage caused by Septoria includes premature senescence and loss of leaf area. A reduction in photosynthetic capacity leads to weakened plants, reduced runner production, and smaller berry yields in the current and following harvest seasons.

• Sanitation by removing and destroying old, infected foliage after the harvest.
• Maintaining proper row spacing to ensure good air circulation and rapid leaf drying.
• Applying preventive fungicide sprays if environmental conditions favor disease outbreak.
• Choosing resistant strawberry cultivars for planting in high-risk areas.