EVALUATION OF YIELD AND WINE QUALITATIVE PARAMETERS FROM GRAPEVINES EXPRESSING FOLIAR SYMPTOMS OF GRAPEVINE TRUNK DISEASES IN SLOVAK CLIMATIC CONDITIONS

Grapevine trunk diseases represent a serious threat to viticulture, posing substantial challenges to the sustainability and productivity of vineyards. Fungal pathogens associated with the grapevine trunk diseases complex decompose the wood matter in grapevine trunks, leading to the disruption of vascular tissue integrity and the subsequent disruption of water and nutrient translocation within the plant. The aim of the work was to compare the yield and qualitative parameters of musts and wines from symptomatic and asymptomatic grapevines. The grape originated from the Nitra wine-growing district, from varieties Riesling Italico and Cabernet Sauvignon, aged 17 years, were used. Grapes from symptomatic and asymptomatic grapevines were processed into must and wines. The differences in yield quantity and physicochemical parameters of must and wine were analysed. Fourier transform infrared spectroscopy was used to analyse the physicochemical parameters. To test the statistical significance of the results, the Tukey's test (p <= 0.05) was applied. Symptomatic grapevines of Cabernet Sauvignon exhibited significantly lower cluster weight and yield compared to asymptomatic grapevines, with a decrease of 504.71 g per bush. For Riesling Italico, no significant difference in yield was found. The must from symptomatic grapevines had significantly lower total sugar content, with Cabernet Sauvignon showing a decrease of 51.29 g/L and Riesling Italico a decrease of 23.72 g/L, along with higher acidity in Cabernet Sauvignon (+1.54 g/L). These findings confirm that grapevine trunk diseases exert a detrimental effect on both yield and must quality, with notable variability observed between grape varieties.