Chrysanthemum white rust
CLASSIFICATION
Fungi, Basidiomycetes, Pucciniomycotina, Pucciniomycetes, rust, Pucciniaceae, Puccinia, Puccinia horiana
ABOUT
Chrysanthemum white rust is a fungal disease caused by Puccinia horiana. It leads to the development of yellow or green spots on the upper surface of the leaves, which can later become brown and necrotic. Pink or white pustules on the bottom side of leaves are also characteristic.
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. Destroy heavily infected plants.
- Chemical
If necessary, apply fungicide containing triticonazole (GHS09: Environmental hazard).
If necessary, apply fungicide containing tebuconazole (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).
Disinfect tools, infected flower pots, and hands to avoid disease transmission.