Cercospora leaf spot
Cercospora leaf blight
CLASSIFICATION
Fungi, Ascomycetes, Pezizomycotina, Dothideomycetes, Dothideomycetidae, Mycosphaerellales, Mycosphaerellaceae, Cercospora
ABOUT
Cercospora leaf spot is an infectious fungal disease with typical symptoms of purple spots with a gray center. The spots first appear at the bottom leaves of the plant and spread toward the top of the plant.
How to treat?
- Biological
If possible remove and destroy the infected 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 tetraconazole (GHS07: Harmful, GHS09: Environmental hazard).
If necessary, apply fungicide containing tebuconazole (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.