Chalaropsis root rot

The causative agent of this disease is the fungus Chalaropsis thielavioides, belonging to the mitosporic fungi. It is a soil-borne pathogen that produces highly resistant chlamydospores, allowing it to persist in the soil or decaying organic matter for several years, waiting for favorable conditions to infect a host.

This pathogen affects a wide variety of plants, including ornamental species, tree seedlings, and vegetable crops such as carrots and celery. It is particularly notorious for causing post-harvest losses, where it can cause significant damage to stored root crops, making them unmarketable.

Symptoms of the infection include the appearance of dark, sunken lesions on the plant surface. As the fungus colonizes the tissue, the infected areas turn black or dark brown, often becoming dry and brittle. In some cases, the tissue may appear charred, which is a classic diagnostic sign of this particular fungal infection.

Development is favored by high humidity, poor aeration, and moderate temperatures. The fungus easily infects host plants through wounds caused by harvesting tools, insects, or environmental stress. Once inside a storage facility, the disease can spread rapidly from infected to healthy roots via contact or airborne spores if humidity is not controlled.

Integrated pest management strategies are essential for effective control of Chalaropsis thielavioides. Key practices include:

• Proper crop rotation to reduce inoculum build-up in the soil.
• Sanitation of harvesting and storage facilities using approved disinfectants.
• Careful handling of produce to minimize mechanical injury during harvest.
• Maintaining optimal airflow and low humidity in storage areas to inhibit fungal growth.