Bruinrot

Bruinrot, known in English as brown rot, is a common fungal disease affecting apples, pears, and other stone and pome fruits, as well as ornamental Prunus species. It is caused by several related fungi in the genus Monilinia, with Monilinia fructicola, Monilinia laxa, and Monilinia fructigena being the most important pathogens in different regions. The disease is characterized by brown, sunken lesions on fruit that rapidly decay into a soft, brown mush. Infected fruit may stay attached to the tree or become mummified and persist on branches, serving as sources of inoculum for subsequent infections. The fungus can also cause blossom blight and twig dieback in some hosts.

Life cycle and infection: Overwintering occurs in mummified fruit and cankers on branches. In spring and early summer, warm, wet conditions promote spore production and dispersal by wind and rain splash. Infection commonly enters through natural openings or wounds in fruit, stems, or blossoms and spreads within the fruit and adjacent tissues.

Management: Control relies on integrated pest management. Sanitation is critical: remove and destroy mummified fruit and infected wood; prune to increase air circulation and light penetration; dispose of infected material away from the orchard. Timely fungicide applications during vulnerable stages (pre-bloom, petal fall, and early fruit development) can reduce infection, and resistant cultivars are preferred where available. Postharvest handling plays a role in storage rot; cool, dry storage and careful selection of fruit reduce losses.