Dependence of Fresh Grapes and Wine Taste Scores on the Origin of Varieties and Weather Conditions of the Harvest Year in the Northern Zone of Industrial Viticulture in Russia

Climate change affects all characteristics of grapes, including the taste of fresh berries and wine. The purpose of this study was to reveal the dependence of fresh grapes taste scores (GS) and wine taste scores (WS) on the origin of the varieties and weather conditions of the harvest year in the northern zone of industrial viticulture in Russia. The material used in the study were taste scores of 232 grape varieties from the Don Ampelographic Collection (47°25′ N 40°03′ E) 1981–2019. The correlation analysis, ANOVA, and regression were used. It was shown that GS negatively correlated with productivity, and WS with the berry mass of variety. In recent decades, GS have increased in groups of varieties of various interspecies origin, and WS have not changed. Regression models revealed that the reason for GS improvement was in the growth of average temperature above 15 °C, while WS varied depending on the sum of precipitation for the period with temperatures above 20 °C, which did not have a reliable trend. Together with data on the growth of grape yield and sugar content, the results indicate that observed climate warming is favorable for grapevine cultivation in the northern zone of industrial viticulture in Russia

MODEL OF TEMPERATURE THRESHOLDS INFLUENCE ON GRAPE SEASONAL DEVELOPMENT

Phenology is an important indicator of climate changes and informs us about the compliance of the variety with climatic conditions. Plant phenology is most often predicted by the sum of degree days, but the accuracy of forecasts is insufficient, especially in conditions of climate change. Regression analysis of 71 grape varieties from Y. I. Potapenko Don ampelographic collection (Russia) in 1981-2014 revealed relationship between grape phenodates (bud break, flowering) and dates of transition air temperatures above temperature thresholds of these phases. On this basis, we have created a simple dynamic model of grape phenology. The time from flowering to ripening was assumed constant for variety. In was realized as a computer program SEASONS. The purpose of this work was to verify and validate the model. Model was parametrized and verified for 12 grape varieties in 1981-2014. Model was validated on the test period of 2015-2017. The approximation error of the SEASONS was 3-5 days for the date of bud break and flowering and 6-9 days for ripening, or 5.1-8.0% for production period duration. The forecast error for production period for the model was 4%, on the base of DD was 11%. This result confirms the quality of the model and its suitability for forecasting

Long-Term Analysis of the Variability of Agronomic Characters in the VIR Oat Germplasm Collection in Central Black Soil Region of Russia

Climate change has become a significant factor in crop production in the 21st century for many countries. To turn losses into profit, adaptation measures are needed, which are based on the analysis and forecast of economically valuable characteristics of crops. The field trial data were analyzed for 764 oat accessions from the global germplasm collection by the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) in 2001–2019 and the cultivar ‘Gorizont’ in 1990–2019 in Yekaterinino Experiment Station of VIR (Tambov Province, Russia, 52°59′ N, 40°50′ E). A progressive shortening of the growing season and a yield increase were observed during the study both in the mean values for the tested accessions and in the cv. ‘Gorizont’. Grain yield variability of cv. ‘Gorizont’ across the years was also associated with 1000 grain weight variations. The models predict a further reduction in the growing season by 2.4 days/10 years, mainly caused by an increase in temperatures above 15 °C, and an increase in yield by 47.6 g/m2/10 years, mainly caused by an increase in the temperature in May. ANOVA demonstrated that the highest yields in Tambov Province were produced by accessions from Ulyanovsk Province, Ukraine, Moscow Province, Norway, Germany, and Poland