Grapevine (Vitis vinifera) crop protection strategies are designed to modify microbial communities by reducing or elimination pathogens. However, little is known about how these interventions affect non-target organisms. The fungal microbiota present on grape surfaces plays a critical role, not only in winemaking, where native yeasts can aid fermentation, but also in determining the storage quality of table grapes. Concerns about off-target impacts on microbiota have driven the exploration of more targeted crop protection methods, such as RNA-interference (RNAi) approaches, which offer the promise of suppressing harmful pathogens while potentially preserving beneficial microbial populations. RNAi methods work by targeting and silencing essential genes in pathogens, reducing their ability to infect the crop. Our work forms part of a broader platform to evaluate the efficacy of new RNAi-based crop protection solutions, including BioClay™, for the control of botrytis diseases in wine grapes and other crops. BioClay™ contains pathogen-targeting double-stranded RNA (dsRNA) molecules, formulated in clay matrix to enhance the stability and persistence of dsRNA on plant surfaces. Given the promising potential of RNAi-based approaches to selectively target pathogens, we sought to evaluate how BioClay™ formulation components may influence the broader microbial community on grape surfaces, compared to existing fungicide products. Bunches of Riesling grapes were collected from conventionally managed vineyards in Tasmania and South Australia, a week prior to their expected harvest dates. Spray treatments were applied in controlled laboratory environments to grape bunches, which were then mounted, via petioles, in saturated floral foam. As well as double stranded RNA (dsRNA) and clay combinations treatments included conventional and biological botryticides, water and bleach solutions. After a 7-day incubation period, surface microbes were collected, DNA was extracted, and the relative population abundance was determined using high throughput amplicon sequencing of a portion of the fungal ITS region (Varela et al. 2021). Results showed no distinct changes in the average proportion of fungal genera in untreated bunches over the 7-day duration of the trial. There were differences in microbial communities when the two regions were compared. South Australian samples had an average higher abundance of Eppicoccum spp., while Cladosporium and Aureobasidium spp. were higher in Tasmanian samples. Principal coordinates analysis showed the South Australian samples, to cluster separately from Tasmanian samples, regardless of treatment. The controls and constraints of the techniques will be discussed in the context of interpreting treatment effects, grape disease status as well as application in different crop types.