Loquat brown rot

The causative agent of the disease is the fungus Monilinia mespili, an ascomycete specifically associated with plants of the Mespilus genus. This pathogen is responsible for a type of brown rot or leaf blight that can significantly affect the health and yield of medlar trees. It is a specialized parasite that thrives when environmental conditions favor fungal growth.

The disease primarily impacts leaves, blossoms, and young fruits of the host plant. By invading these organs, the fungus disrupts normal physiological functions, often leading to necrosis and premature organ drop. If left unmanaged, the pathogen can weaken the overall vitality of the tree, making it more susceptible to environmental stress and secondary pests.

Symptoms typically manifest as necrotic brown spots on the leaves, which eventually extend to petioles and twigs. In humid weather, these infected areas develop a characteristic grayish-brown fungal sporulation. Flowers may also be blighted, shriveling rapidly and turning brown, which serves as a visual indicator of an active fungal infection within the canopy.

Environmental conditions such as cool temperatures combined with high moisture are optimal for the germination of conidia and infection of host tissues. The fungus overwinters in mummified fruits and infected leaf litter beneath the tree. When spring rains occur, the spores are dispersed by splashing water and wind, creating a cycle of infection that repeats throughout the growing season.

Effective management requires a combination of sanitation and chemical interventions. Reducing the amount of overwintering inoculum is the first step in successful disease control.

• Removal and destruction of mummified fruits
• Pruning and removal of infected branches and twigs
• Application of copper-based or systemic fungicides during early spring
• Ensuring adequate airflow within the tree canopy