Brown rot

The fungus Monilinia fructigena is the primary pathogen responsible for brown rot, a devastating disease affecting pome fruits such as apples, pears, and quinces. This fungus attacks fruit tissue, leading to rapid decay and significant economic losses for growers worldwide. It primarily enters the plant through physical wounds or insect-inflicted openings.

The initial symptoms are characterized by small, brown, circular spots on the surface of the fruit. As the infection progresses, the lesion grows rapidly, and characteristic grayish-yellow tufts of conidia appear in concentric circles. The fruit flesh becomes soft, mealy, and eventually transforms into a shriveled, hardened "mummy" that remains attached to the branch or falls to the ground.

The development of brown rot is strongly influenced by environmental factors, particularly high humidity and moderate temperatures ranging from 20°C to 25°C. Spores are disseminated by rain, wind, and various insects. The pathogen survives the winter in mummified fruits and infected woody tissues, which serve as the primary source of inoculum for the next growing season.

The economic impact is severe, as the disease can compromise the entire harvest both in the orchard and during post-harvest storage. Infected fruits serve as secondary infection sources, allowing the fungus to spread rapidly within storage facilities. Proper management is essential to prevent large-scale crop spoilage and to maintain the quality of commercial produce.

Effective control strategies include:

• Sanitation, including the removal and destruction of mummified fruits from both the tree and the orchard floor.
• Pruning for better air circulation and light penetration to reduce humidity around the fruit.
• Timely application of protective and systemic fungicides during critical growth stages.
• Control of fruit-damaging insects to reduce entry points for the fungus.
• Maintaining optimal storage conditions, such as low temperatures and proper ventilation.