Monilinia

Monilinia is a genus of plant-pathogenic fungi in the family Sclerotiniaceae. It includes several species that cause brown rot diseases in fruit crops, with the most economically important being Monilinia fructicola, Monilinia fructigena, and Monilinia laxa. These fungi are widely distributed in temperate regions and can affect both stone fruits and, to a lesser extent, pome fruits.

The diseases caused by Monilinia species are collectively known as brown rot. Infected fruit develop sunken, brown lesions that rapidly expand, often with a fuzzy gray‑white to tan conidial growth under warm, humid conditions. In some cases blossoms and young twigs may be infected, leading to canker formation and dieback. In the orchard, mummified fruit can remain on trees or on the ground and serve as sources of inoculum for the next season.

The life cycle of Monilinia involves overwintering structures such as sclerotia in mummified fruit, cankers, or soil. In spring, ascospores released from sexual fruiting bodies or conidia are dispersed by rain and wind, infecting blossoms and young fruit. Under favorable temperatures and moisture, fruit becomes colonized, producing more conidia and, in storage, continuing to rot postharvest. Sclerotia persist to initiate new cycles.

Management relies on sanitation, including removal of mummified fruit and diseased wood, pruning for better air circulation, and careful fungicide use with rotation of modes of action to delay resistance. Proper harvest, handling, and storage practices are also important to limit postharvest losses. Monilinia remains a major concern in commercial orchards and fruit production systems worldwide.