Phialophora wilt of cyclamen

Phialophora wilt of cyclamen is a vascular fungal disease caused by the pathogen Phialophora cyclaminis. This fungus primarily attacks the root system and the vascular tissues of the cyclamen tuber, leading to the disruption of water and nutrient transport throughout the plant.

While cyclamen is the primary host, the pathogen is known for its persistence in the soil. It can survive in infested potting media for extended periods, posing a significant risk in commercial greenhouse production where environmental conditions are optimized for both the plant and the fungus.

Symptoms typically begin with the yellowing and wilting of the lower leaves. As the infection progresses, the plant loses its overall turgor despite adequate soil moisture. A diagnostic sign is the darkening of the vascular bundles within the petioles and the crown, which becomes visible upon dissecting the plant tissues.

The development of the disease is highly correlated with environmental factors such as high soil moisture, poor drainage, and high ambient temperatures. The fungus typically enters the plant through the root system, often exploiting wounds caused by repotting or root-feeding pests, which facilitates rapid colonization of the vascular system.

Management strategies focus on strict sanitation and preventive measures. These include using sterilized potting media, ensuring high-quality plant stock, and maintaining optimal irrigation regimes. Once a plant is visibly infected, it is generally recommended to remove and destroy it to prevent the spread of the fungus to healthy neighboring plants.