Cylindrocladiella root rot

Pathogen and disease type
Cylindrocladiella root rot is caused by the fungus Cylindrocladiella peruviana. It is a soil-borne pathogen known for causing necrotic decay of roots and crown tissues. This type of disease disrupts the plant's vascular system, preventing water and nutrient uptake, which eventually leads to the collapse of the plant.

Affected crops
This pathogen has a wide host range, primarily affecting various greenhouse, ornamental, and woody plants. Cyclamen persicum (Persian cyclamen) is highly susceptible to this infection, often showing severe symptoms under commercial production conditions. Other hosts include eucalyptus seedlings and various container-grown nursery crops.

Symptoms and signs
Visible symptoms typically start with chlorosis (yellowing) and wilting of the lower foliage. As the disease progresses, the entire root system becomes dark brown to black and necrotic. In cyclamens, the decay often advances from the root crown into the tuber, resulting in soft rot that turns the internal tissue into a mushy state.

Conditions for development and severity
The fungus thrives in environments with high humidity, poor soil drainage, and warm temperatures. It spreads easily through contaminated potting media, irrigation water, and infected nursery tools. The severity of the disease is significant, as it can cause rapid plant mortality and is difficult to eradicate once it establishes in a greenhouse facility.

Control and prevention measures

• Use only disease-free planting stock and sterilized growing media.
• Implement strict irrigation management to prevent waterlogged conditions.
• Regularly sanitize all greenhouse surfaces, pots, and gardening tools.
• Remove and destroy infected plants immediately to prevent spore dispersal.
• Apply preventative or curative systemic fungicides specifically labeled for soil-borne pathogens.