Grape Quality Parameters in Western Carpathian Region under Changing Climatic Conditions as Influenced by Drought

Abstract

Western Carpathians are historically the northern range traditional grapevine growing areas since the Middle Ages. The mean anual temperature has increased by about 1.1 o C during the last century in Slovakia. Elevated temperature impacted the growing conditions of grapevine. Together with the increased temperatures, higher frequency of drought periods and parameters are evident. Traditional grape producing areas are facing new challenges. Except for the accelerated grapevine phenology, pathogene infection pressure and occurence of pests including new ones, as well as the quality of grapes influencing wine quality, are changing. In order to evaluate the drought impact on the quality parameters of grapes the locality of the Cultivar Testing Station in Dolné Plachtince which belongs to the Central Slovakian grape producing region was chosen. Interanual variability of the drought impact on the grape quality was evaluated according to Palmer drought severity index (PDSI). The 1990-2014 period was used as a basis for evaluation. The period with the phenological phase crucial for the grape quality formation was determined. Two groups of cultivars with different ripening periods were selected. Pinot Gris, Muscat Ottonel Weiss, Müller Thurgau represented the early ripening cultivars (OIV earliness code 4 and 5), whereas Grüner Veltliner, Riesling, Welschriesling represented the late ripening cultivars (OIV code 8 and 9) were used. The cumulative values of PDSI for the crucial periods were calculated. The PDSI values as well as the sugar and acid contents were correlated to find the strength of relation between them. Short drought periods did not influence the grape quality significantly, while long drought periods caused a decrease of the acid content and an increase of the sugar content. Though the tendency was clear, the correlation level was mostly low. The most sensitive period in this sense was July-September; however, it was influenced by the ripening term of individual cultivars. The results suggest the necessity of a thorough approach to cultivar selection, taking into account its vitality and ability to preserve a satisfactory acid content in grapes by the harvest date.

Evaluating the Chemical Hazards in Wine Production Associated with Climate Change

“…The IPCC Third Assessment Report showed that the number of frost days would reduce under climate change, raising several negative impacts on the grapevine [ 38 ]. Since sustained drought affects grape quality [ 39 ], we used two indices to evaluate the drought (scPDSI and SPEI). Firstly, the scPDSI is a standardized index that spans between −10 (dry) to +10 (wet) and has a long-term memory of previous climate conditions (and thus it is less sensitive to drought recovery) [ 40 ].…”

Evaluation of Drought – Review of Drought Indices and their Application in the Recent Studies from Slovakia

“…The ongoing warming trend of summer months suggests further intensification of drought spreading from the continual increase of evapotranspiration over the next decades. Bernáth et al (2020) evaluated the drought impact on the quality parameters of grapes in the locality of the Cultivar Testing Station, Dolné Plachtince. Interanual variability of the drought impact on the grape quality was evaluated according to PDSI.…”

Assessment of the Elements of the Sudan Grass Cultivation Technology in the Zone of Dry Steppes

“…By the peculiarities of its photosynthetic cycle, Sudan grass belongs to type C4, which determines its high productivity. In dry weather conditions, it ensures stable yields, compared to the traditional fodder crops, it grows quickly after harvesting and can be used for silage, haylage, grass flour and green mass (Bernáth et al, 2020).…”