The mycobiome is comprised of a rich array of fungal species that compete for resources, and species diversity and prevalence exhibit a dynamic structure under the influence of many factors. While the host fruit develops, the prevalence and the arrangement of fungal species in this mycobiome also change, forming a dynamic microenvironment. In this study, fungal diversity on peach fruit surfaces at different developmental stages have been determined to better understand the changes in fungal diversity and disease occurrence by using metabarcoding of the full ITS region and processing the obtained high-throughput sequencing data with various bioinformatic analyses. It has been found that fungal diversity in early developmental stages is higher, and the diversity declines as the fruit matures, likely due to more prevalent fungal species establishing themselves on the surface as the fruit develops. Additionally, this research reveals that the prevalence of pathogens does not necessarily mean that disease will develop, as pathogenic species were found to be at higher prevalence percentages when compared to non-pathogenic species in healthy fruit samples. This study also identified the Monilinia polystroma species at a molecular level for the first time in Türkiye
however, no symptomatic signals were recorded on the host. The study provides valuable data for mycobiome studies, while also highlighting its importance in optimizing sustainable disease management strategies.