Pathogen Information
Septoria Leaf spot is cause by the Septoria genus with the most notible being the S. lycopersici which infects the tomato, common symptoms include:
- Dark bumps with a light spot in the middle
- Yellowing surrounding the spots
- A small black speck will emerge as the spores develop
- Spots that can merge as disease progresses
Environmental Conditions
- Temperature: 65-75°F
- Humidity: 90%+, thriving with prolonged periods of wetness
- Most effected species: Cucurbitaceae, Solanaceous, and many ornamentals
Disease Progression
Early Stage
Small, dark brown spots appear on leaves, often having a yellow halo
Mid Stage
Spots enlarge, some merging as brown specks appear in the center of the spots
Late Stage
Leaves yellow and die and defoliation occurs
Prevention Methods
- Avoid overhead irrigation
- Maintain proper plant spacing
- Remove and destroy infected plant debris
- Use disease-free seeds and resistant varieties
- Rotate crops with non-susceptible plants
- Keep leaves dry and improve air circulation
Treatment Options
- Chlorothalonil-based fungicides
- mancozeb treatments
- Copper-based fungicides
*There in no cure only prevention methods*
