Efficacy of biorational and synthetic fungicides for control of blossom blight, preharvest and postharvest brown rot in nectarine in South Carolina, 2026

Blossom blight and brown rot, caused by the fungal species Monilinia fructicola in the southeastern United States, are two major diseases of peach worldwide that drive the spray program on commercial farms. Symptoms include blighted blossoms, twig cankers, and brown rot of the fruit, where the pathogen produces conidia that are dispersed by wind, water, and insects. This report evaluates the efficacy of bloom sprays for blossom blight and preharvest sprays for preharvest and postharvest brown rot control. The trials were conducted in 2026 in Seneca, SC, on 12-year-old Prunus persica var. nucipersica ‘Juneprincess’ nectarine trees. Results from these trials will help integrate new synthetic and biorational fungicides into IPM programs for peach and nectarine orchards in the southeastern USA.