Botryosphaeria Dothidea fungus in Epicactus plants
Updated: Oct 16, 2023
Botryosphaeria Dothidea: This is one of the most insidious infections in our epicactus plants.
This fungal infection causes blotchy red/brown spots on the stems of plants.
The pathogens caused by this disease can spread along, or through the stem, killing tissue in its wake.
Because the infection penetrates the tissue a surface spray with fungicide will not stop it.
What surface sprays WILL do is to prevent new infections from spores landing on the cladode surfaces which then take hold and infect the host.
The spores of this infection can travel from plant to plant on the wind or by water splash, so it’s important to remove any plant from proximity to others.
This disease is most often present in wet or humid conditions.
The spots are typically flat but slightly raised compared to adjacent normal areas. Sometimes these spots have an appearance of a circular spot and other times multiple irregular spots that may merge.
Botryosphaeria may first present as yellow areas on a cladode that then develop the darker spots mentioned above.
Because of unsterile pruning practices, this disease has become quite common in many parts of the world across many plant species.
We should all be aware of it and respond swiftly to any outbreaks.
TREATMENT:
1. Prune off infected cladodes. They cannot recover but they WILL spread the infection if not removed.
2. Disinfect pruning shears after use.
3. Treat plant with a Copper Sulphate fungicide and Yates Anti-rot, or a systemic fungicide.
