Influence of cover crops in a Tempranillo vineyard grown under the edaphoclimatic conditions of the Appellation of Origin Rueda

Valpolicella is a famous Italian wine-producing region. One of its main characteristic is the intensive use of grapes that are submitted to post-harvest withering. This is rather unique in the context of red wine, especially for the production of a dry red wine such as Amarone. Amarone wines produced in Valpolicella different geographic origin are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity. Aroma is the product of a biochemical and technological series of steps, resulting from the contribution of different volatile molecules deriving from grapes, fermentations, and reactions linked to aging, as well as one of the most important features in the expression of the geographic identity and sensory uniqueness of a wine.

Root system architecture (RSA) is important for soil exploration and edaphic resources acquisition by the plant, and thus contributes largely to its productivity and adaptation to environmental stresses, particularly soil water deficit. In grafted grapevine, while the degree of drought tolerance induced by the rootstock has been well documented in the vineyard, information about the underlying physiological processes, particularly at the root level, is scarce, due to the inherent difficulties in observing large root systems in situ. The objectives of this study were to determine genetic differences in the root architectural traits and their relationships to water uptake in two Vitis rootstocks genotypes (RGM, 140Ru) differing in their adaptation to drought. Young rootstocks grafted upon the Riesling variety were transplanted into cylindrical tubes and in 2D rhizotrons under two conditions, well watered and moderate water stress. Root traits were analyzed by digital imaging and the amount of transpired water was measured gravimetrically twice a week. Root phenotyping after 30 days reveal substantial variation in RSA traits between genotypes despite similar total root mass; the drought-tolerant 140Ru showed higher root length density in the deep layer, while the drought-sensitive RGM was characterised by shallow-angled root system development with more basal roots and a larger proportion of fine roots in the upper half of the tube. Water deficit affected canopy size and shoot mass to a greater extent than root development and architectural-related traits for both 140Ru and RGM, suggesting vertical distribution of roots was controlled by genotype rather than plasticity to soil water regime. The deeper root system of 140Ru as compared to RGM correlated with greater daily water uptake and sustained stomata opening under water-limited conditions but had little effect on above-ground growth. Our results highlight that grapevine rootstocks have constitutively distinct RSA phenotypes and that, in the context of climate change, those that develop an extensive root network at depth may provide a desirable advantage to the plant in coping with reduced water resources.

The pinking of in white wine is the turning of color from yellow to salmon hue. White wines obtained from certain grape varieties (e.g. Chardonnay, Sauvignon blanc, Riesling, Trebbiano di Lugana) showed to be susceptible to pinking [1] that has been evaluated by an assay providing the addition of hydrogen peroxide. Even if its appearance does not seem to affect the sensory properties [2], strategies are necessary for its removal. Nowadays, the treatment with polyvinylpolipirroline (PVPP) was reported to significantly decrease the pink color [3].

This work was aimed at setting up a methodology to define and map the «Unités Terroir de Reconnaissance» (UTR), combining environmental information stored in a Soil Information System with experimental data coming from benchmark vineyards of Sangiovese vine.

Viral diseases are a significant cause of both decreased grape quality and vineyard production. Important agents include grapevine leafroll-associated virus (glravs) and grapevine rupestris stem pitting-associated virus (grspav). However, conducting phytosanitary analysis of vineyards for viruses on-site is challenging, and molecular testing is generally expensive.