Atmospheric modeling: a tool to identify locations best suited for vine cultivation. Preliminary results in the Stellenbosch region

In this video recording of the IVES science meeting 2023, Simone Vincenzi (Department of agronomy, food, natural resources, animals and environment (DAFNAE), University of Padova, Italy) speaks about the prevention of quercetin precipitation in red wines with a promising enzymatic solution. This presentation is based on an original article accessible for free on OENO One.

Vine cane extracts are a valuable byproduct due to their rich content of polyphenols, vitamins, and other beneficial compounds, which can affect and benefit the vine and the grapes. This study aims to evaluate the response of grapevine plants to irrigation with water supplemented with a vine cane extract, both at physiology response and phenolic composition in different parts of the plant (root, trunk, shoot, leaf, and berry).
Cane extract was obtained by macerating crushed pruning residues with warm water (5:1) and pectolytic enzymes. Two-year-old potted plants were irrigated with water (Control) while others were irrigated with cane extracts, either at 1:4 (w/v, cane extract/water; T 1:4) or at 1:8 (w/v, cane extract/water; T 1:8).

Cover crops are increasingly considered in Mediterranean climate vineyards due to a combination of agronomic and regulatory considerations. However, the soil under the vines themselves is typically kept free of vegetation by mechanical plowing or herbicide spraying. Taking into account that these practices may convey a number of non-favourable economic and environmental implications, and the fact that drip irrigation can ease the use of cover crops under the vines, the aim of this work was to evaluate the agronomic implications and the changes in soil physical and biological properties caused by an under-vine cover crop in a Mediterranean area.

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

A study of soil pH on the experimental field resulted in a high variability of pH on a very small scale. This kind of heterogenity in soil pH have effects on growth of two grapevine varieties on rootstock Kober 5BB