Microbiota of Vitis vinifera cv. Barbera grapes: a focus on the mycobiota and a look at the culturable indigenous Saccharomyces spp. strains under three different experimental conditions in vineyard

The doctoral research, undertaken by collaboration between UPO-DISIT and CREA-VE, was inspired by the project "Elicitori di resistenza a supporto della difesa dalla Flavescenza dorata della vite", coordinated by CNR-IPSP, and focused on assessing the efficacy of BION 50WG® against Flavescence doré and ESCA diseases in grapevines. The PhD research unfolded at the CREA-VE experimental vineyard under Integrated Crop Management. The study compared three experimental conditions: Control, Integrated pest management (IPM) involving the use of agrochemicals during the growth season, especially during ripening, targeting main parasites and pathogenic fungi when infestation thresholds were reached; Bion, IPM enhanced with the phytostimulant BION®50WG (50% Acibenzolar-S-Methyl) from Syngenta, applied bi-weekly via foliar spray during the growing season, and using a 5 hi water suspension at a dose of 20g/hl BION; Water, IPM combined with the nebulization of 5 hl of water on leaves to simulate increased humidity without the active molecule, akin to a light rain with a washout effect on previous treatments. The PhD study had three primary goals: to assess and compare biodiversity indexes of the mycobiota among the three tests using the metabarcoding technique; to describe the composition of cultivable yeasts on the berry skin in each trial; to observe whether the three trials affected spontaneous alcoholic fermentation or the yeast species driving the process, predicting any anomalies in winemaking. Statistical analysis determined that the three experimental conditions did not significantly affect the mycobiota at ripening time, nor did they impact spontaneous fermentation. Consequently, it is plausible to assume that BION®50WG does not induce shifts in fungal communities or pose troubles in winemaking processes.