Choanephora wet rot

Taxonomic position and pathogen nature: Choanephora infundibulifera belongs to the kingdom Fungi, phylum Mucoromycota, and the genus Choanephora. It is a filamentous pathogen responsible for causing significant wet rot and mold-like decay in various plant species. As a facultative parasite, it thrives in environments rich in plant debris and soil, waiting for favorable conditions to infect susceptible host tissues.

Diseases and host crops: This pathogen is primarily known for causing blossom blight and fruit rot in diverse vegetables, including tomatoes, peppers, cucumbers, beans, okra, and amaranth. The disease is characterized by the rapid collapse of succulent tissues, often accompanied by the emergence of a distinctive mass of sporulation that turns from white to dark brown or metallic as it matures.

Biology and life cycle: The lifecycle of Choanephora infundibulifera is driven by asexual reproduction through the production of numerous sporangiospores. These spores are highly mobile and are disseminated primarily by wind, splashing rain, and insect vectors. Once they land on suitable plant surfaces, they germinate and penetrate the host tissue, rapidly secreting enzymes that degrade plant cell walls, leading to soft rot symptoms.

Conditions for development and damage: High humidity (above 85%) and warm temperatures (ranging from 25°C to 30°C) are the primary environmental drivers for disease outbreaks. Under these conditions, the fungus can devastate entire fields within a very short period. The economic damage is severe, as affected fruit becomes unmarketable and the disease can compromise the structural integrity of the entire plant.

Control and management measures: Managing Choanephora infundibulifera requires a holistic integrated pest management (IPM) strategy focused on sanitation and environmental control:

• Improving drainage and reducing humidity within high tunnels or greenhouses.
• Removing and destroying infected plant tissue immediately upon detection.
• Ensuring adequate plant spacing to facilitate airflow and reduce micro-humidity.
• Applying preventive fungicides labeled for mucoraceous fungi control.
• Practicing strict crop rotation with non-host species to reduce soil inoculum.