Relationships between temperature variability and phenological timing of grapevines in the Lisboa wine region

Abstract

Climate is one of the main conditioning factors for viticulture. Furthermore, there are significant weather variations among years, which influence grapevine phenology. In this study the impact of inter-annual temperature variability on phenological timing is analysed for the Lisboa Wine Region. Among the Portuguese wine regions, this region is the second most important in total production volume. Multivariate linear regressions are used for phenological phases modelling over the period from 1995 to 2010. Annual dates of budburst, flowering and véraison of Jaen (syn. Mencía), Síria and Touriga-Franca Vitis vinifera varieties from an experimental vineyard (Dois Portos – 39.0ºN, 9.2ºW, 110 m) are selected in this modeling approach (dependent variables). Monthly means of the maximum, minimum and mean temperatures are used as independent variables. Correlations are identified between the phenological events and temperatures, being the most statistically significant between flowering dates and maximum/mean temperatures during March and April. Phenological timing characteristics and phenological intervals between varieties are also assessed. The study confirmed that springtime temperatures have a strong influence on grapevine phenology and consequently on yield and wine quality.