Influence of viticulture on the temporary evolution of the landscape: the case of the AO Ribera del Duero (Central Spain)

AIM: A genetic study of four wine T. delbrueckii strains was done. Spore clones free of possible recessive growth‐retarding alleles with enhanced resistance to winemaking stressing conditions were obtained from these yeasts. METHODS: The genetic marker of resistance to cycloheximide (cyhR) allows easy monitoring of the new mutants obtained from these yeasts.

Today, the concept of precision vine management (or site-specific viticulture) has a great relevance. It is based on the practice of a different management in relation to the different features of the crop site. In this way, all practices should be adapted to the land spatial variability and should be linked to the real needs of vines.

SO₂ play a major role in the stability and wine during storage. Nowadays, the reduction of chemical input during red winemaking and especially the removing SO₂ is a growing expectation from the consumers. Winemaking without SO₂ is a big challenge for the winemakers since the lack of SO₂ affects directly the wine chemical evolution such as the phenolic compounds as well as its microbiological stability.

Three compounds, 3-mercaptohexanol (3MH), 3-mercaptohexyl-acetate (3MHA) and 4-mercapto-4-methylpentan-2-one (4MMP), also known as varietal thiols, have been identified to contribute positively to wine aroma and are responsible for the distinct gooseberry, grapefruit, guava and box tree character found in Sauvignon blanc wines. Certain volatile thiol compounds though, can cause off-aromas of onion, garlic, rubber and rotten egg, this group of molecules is known as reductive sulphur compounds (RSC). This study looks into how the addition of sulphur-compounds to Sauvignon blanc juice contributes to the varietal thiol (3MH and 3MHA) concentration and reductive sulphur compound concentration in South African Sauvignon blanc wine.

The need to rationalize agricultural inputs has recently increased interest in assessing vineyard variability in order to implement variable rate input applications, so-called ‘precision viticulture’. In many viticultural areas globally, precision viticulture is already widely used such as for selective harvesting and variable rate application (VRA) of inputs such as irrigation and/or fertilizer. Robust VRA relies on having a geostatistically accurate map (of one or more vineyard attributes) requiring high sampling densities, which can be cost- and time-prohibitive to obtain. Previous work on spatial interpolation using kriging have upscaled ground-based measurements, but such upscaling strategies are applicable only when vineyard conditions are spatially continuous and satisfies the assumption of second-order stationary processes. Alternatively, mixed models that combine kriging and auxiliary information, such as the regression kriging (RK) method, are more instructive for spatial predictions. In order to improve prediction accuracies, it is therefore necessary to incorporate additional information to achieve accurate spatial patterns with low error.