Brown rot

Brown rot, caused by fungi of the genus Monilinia, is one of the most destructive fungal diseases affecting a wide range of fruit-bearing trees. The pathogen attacks both pome fruits like apples and pears, and stone fruits such as peaches, cherries, and plums, causing significant losses in both yield quantity and fruit quality.

The disease cycle typically involves two distinct phases: blossom blight and fruit rot. The fungus overwinters in mummified fruit, twig cankers, and floral spurs. When conditions are suitable, the pathogen releases spores that infect fresh tissues, leading to the characteristic symptoms of wilting and decay that can ruin an entire harvest.

Symptoms often manifest as sudden wilting and browning of blossoms and young shoots in early spring. As the season progresses and fruits approach maturity, the infection appears as firm, circular brown spots on the fruit surface. These spots eventually enlarge, leading to total rot and the development of grayish, concentric spore tufts on the skin of the fruit.

Environmental factors such as high humidity, frequent rainfall, and moderate temperatures are ideal for the rapid spread of Monilinia. The disease is easily transmitted via wind-blown spores and rain splashes, while physical damage to fruit skins from birds or insects provides easy entry points for the fungal infection to take hold.

Effective management requires a multi-faceted strategy. This includes rigorous orchard sanitation, such as the removal and destruction of infected twigs and mummified fruits, as well as the implementation of strategic fungicide spray programs. Maintaining good orchard airflow through proper pruning and controlling insect pests are also critical for long-term disease suppression.

• Prune out and destroy infected branches and twigs.
• Remove all mummified fruits from trees and the ground.
• Apply fungicides at pink bud and full bloom stages.
• Control insects to prevent fruit skin damage.