This Summerfruit NZ-ALT project evaluated registered biofungicides to test efficacy for Monilinia fructicola (brown rot) control under commercial orchard conditions during the summer of 2025-2026.

Brown rot is a fungal disease in stonefruit that causes blossom blight in spring and fruit rot which can result in significant crop losses. It is currently controlled by multiple spray applications of synthetic fungicides, the reliance on which heightens the risk of fungicide resistance developing.

Following two years of laboratory-based screening, funded by Summerfruit NZ and carried out by Bioeconomy Science Institute (BSI), a field trial was undertaken in the 2025-2026 season in a Hawke’s Bay peach orchard evaluating the four biofungicides identified to be most effective against brown rot.

While all four products reduced brown rot incidence at harvest, only two achieved statistically significant reductions. One product delivered the strongest field performance, achieving 75% control of brown rot at harvest, and is a priority candidate for Summerfruit NZ’s future field testing for adoption into a late season brown rot control spray programme.

Read more about the project:  

• August 2026: Biofungicides add to grower tool box for brown rot control
• September 2025: Cross-sector benefits from summerfruit biofungicide trial