Viticultural zoning in D.O.C. Ribeiro (Galicia, NW Spain)

A total of 52 volatile compounds were measured in varietal Cabernet Sauvignon wines from four sites in Santa Catarina State (Brazil), over two consecutive vintages (2004 and 2005).

Goriška Brda est la région viticole située le plus à l’ouest de la Slovénie, attenante au Collio d’Italie. Goriška Brda (2020 ha de vignobles) a une longue tradition d’élevage viticole. La proximité de la mer Adriatique (Golfe de Trieste) au sud-ouest et des Alpes Juliennes au nord contribue à un climat caractéristique et unique qui influe sur la croissance et la fertilité de la vigne. La constitution des sols, un climat typique et un relief mouvementé provoquent des différences dans la production du raisin, sa quantité et sa qualité. L’utilisation du zonage ou du microzonage permettraient d’atténuer les influences des facteurs climatiques et du sol sur la production de la vigne ou d’en profiter. Pour évaluer la signification des différents facteurs, nous avons résumé et réuni les modèles de différents auteurs.

The research includes an analysis of the impact of weather conditions on phenological development of the vine and grape quality, through monitoring of four experimental cultivars (Chardonnay, Graševina, Merlot and Plavac mali) over two production years. In each experimental vineyard, which were evenly distributed throughout the regions of Slavonia and The Croatian Danube, Croatian Uplands,

Grapevine cultivars are vegetatively propagated to preserve their varietal characteristics. However, spontaneous somatic variations that occur and are maintained during cycles of vegetative growth offer opportunities for the natural improvement of traditional grape cultivars. One advantageous trait for winegrowing is reduced bunch compactness, which decreases the susceptibility to pests and fungal diseases and favor an even berry ripening.

Grapevine yield is a key indicator to assess the impacts of climate change and the relevance of adaptation strategies in a vineyard landscape. At this scale, a yield model should use a number of parameters and input data in relation to the information available and be able to reproduce vineyard management decisions (e.g. soil and canopy management, irrigation). In this study, we used data from six experimental sites in Southern France (cv. Syrah) to calibrate a model of grapevine yield limited by water constraint (GraY). Each yield component (bud fertility, number of berries per bunch, berry weight) was calculated as a function of the soil water availability simulated by the WaLIS water balance model at critical phenological phases. The model was then evaluated in 10 grapegrowers’ plots, covering a diversity of biophysical and technical contexts (soil type, canopy size, irrigation, cover crop). We identified three critical periods for yield formation: after flowering on the previous year for the number of bunches and berries, around pre-veraison and post-veraison of the same year for mean berry weight. Yields were simulated with a model efficiency (EF) of 0.62 (NRMSE = 0.28). Bud fertility and number of berries per bunch were more accurately simulated (EF = 0.90 and 0.77, NRMSE = 0.06 and 0.10, respectively) than berry weight (EF = -0.31, NRMSE = 0.17). Model efficiency on the on-farm plots reached 0.71 (NRMSE = 0.37) simulating yields from 1 to 8 kg/plant. The GraY model is an original model estimating grapevine yield evolution on the basis of water availability under future climatic conditions.  It allows to evaluate the effects of various adaptation levers such as planting density, cover crop management, fruit/leaf ratio, shading and irrigation, in various production contexts.