Septoria leaf spot
CLASSIFICATION
Fungi, Ascomycetes, Pezizomycotina, Dothideomycetes, Dothideomycetidae, Mycosphaerellales, Mycosphaerellaceae, Septoria
ABOUT
Septoria leaf spot is a severe fungal disease caused by Septoria lycopersici which often affects tomatoes and potatoes. The spots are circular with dark brown margins, gray centers, and small black fruiting structures.
How to treat?
- Biological
If possible remove and destroy the infected and dead parts of the plant. Burn it, toss it into the garbage, or bury it deeply. Do not compost.
Remove weeds as well as all dead plant tissue. They may be a source of infection.
Apply ecological products for plant protection (e.g. copper-based spray).
- Chemical
If necessary, apply fungicide containing maneb (GHS07: Harmful, GHS08: Health hazard, GHS09: Environmental hazard).
If necessary, apply fungicide containing chlorothalonil (GHS05: Corrosive, GHS06: Toxic, GHS07: Harmful, GHS08: Health hazard, GHS09: Environmental hazard).
- Disease prevention
Use resistant species and cultivars as well as healthy, certified seeds and seedlings.
Avoid prolonged wetting of the leaves, which can be caused e.g. by overhead irrigation.
Improve the air circulation around the plant (e.g. by pruning excess foliage or increasing the spacing between plants).
Rotate crops. Avoid planting sensitive crops in infested soil.
Disinfect tools, infected flower pots, and hands to avoid disease transmission.