This study concerns firstly the methodology to describe the climate of vineyards, on a macroclimate scale of viticultural regions worldwide. Three synthetic and complementary viticultural climatic indices (potential water balance of the soil over the growing cycle, heliothermal conditions over the growing cycle and night temperature during maturation), validated as descriptors, are used: (1) dryness index (DI) which corresponds to the potential water balance of the soil of Riou's index, here adapted using precise conditions to calculate it, as an indicator of the level of presence-absence of dryness; (2) heliothermal index (HI) which corresponds to Huglin's heliothermal index; (3) cool night index (CI) an index developed as an indicator of night temperature conditions during maturation. These indices are representative of the variability of the viticultural climate worldwide, related to the requirements of varieties, vintage quality (sugar, colour, aroma), and typeness of the wines. A Multicriteria Climatic Classification System (Géoviticulture MCC System) for the grape-growing regions worldwide is formulated based on classes for each of the three climate indices, with elements to explain the results. Three formulated concepts provide the system base: viticultural climate, climatic group and viticultural climate with intra-annual variability (for warm regions with more than one harvest a year in natural climate conditions). The application of the Géoviticulture Multicriteria Climatic Classification System is presented for 97 grape-growing regions in 29 countries. The system is a research tool for grape-growing and wine-making zoning. It also enables work at different levels on the scale, on a world-wide scale or larger -the large grape-growing region, the small grape-growing region, as shown by the studies performed. It allows relating the viticultural climate to the elements of grape quality and the typeness of the wines considering the climatic zone.
<p style="text-align: justify;">Water is an important factor in the terroirs of grape-growing regions. The vine obtains water from rainfall and the water table and when it is in short supply, it is necessary either to irrigate or accept the effects of water stress. Depending on the intensity of the water stress and the period at which it occurs, it may or not be favourable for the harvest and the wine it is used to produce. The objective of this article is to provide some information on the relationship that exists between the vine and water. The climate and the soil, which are essential but not the sole elements of this relationship will only be touched upon, but we will discuss in a non exhaustive way, with information’s from the bibliography or from our research, the following aspects: the root system, vegetative growth, the relationship between plant architecture and the water status of the vine, the carbon balance and the biochemical composition of the grape berry in relation to vine water status. We will also present the currently available techniques for measuring vine water status and its evolution during the vegetative cycle as a function of water reserves in the soil easy to use by the roots. Finally examples are presented of possible recommendations for vine cultural practices as a function of the vine water status evolution during the growth, according to the predawn leaf water potential thresholds.</p>
The influence of berry size on wine quality is a matter of debate. With the aim to contribute to that debate, a study of the influence of the varieties Tannat
En fonction de données nouvelles concernant les caractères sexuels dans le genre Vitis, en particulier la preuve de l'apparition de mâles dans des descendances de croisements entre hermaphrodites, une modélisation générale de l'hérédité des stérilités mâle et femelle est développée. Les résultats fournis par le meilleur modèle expliquent les observations effectuées jusqu'à ce jour et mettent en exergue des phénomènes de multiallélisme et d'épistasie. ,> Mots clés additionnels : Sexe, fleur, vigne, multiallélisme, épistasie. SUMMARY Male and female sterility in the genus Vitis. I. Modeling of their inheritance. A general model of the inheritance of male and female sterility in Vitis has been developed starting from new data on sexual characters in the genus Vitis, and particularly from evidence of the occurrence of males in progenies from crosses between hermaphrodites. The results given by the best model explain the present observations and indicate multiallelic and epistatic phenomena.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.