Freeze-thaw temperature oscillations promote increased differential gene expression during grapevine bud dormancy

Magnesium (Mg) deficiency poses a significant challenge to viticulture, particularly affecting Welschriesling (WR), a key grape variety in Austrian and Central European vineyards.

In previous experiments carried out in Bologna on Sangiovese grapevines raised with the Australian “Minimal Pruning” system, it has been shown that this system left an excessive burden of buds on the vine.

Leaf removal in the fruit-zone has been employed to improve cluster light exposure and ventilation and therefore increase metabolite accumulation and reduce botrytis incidence in berries. When applied before flowering (early defoliation – ED), it can also decrease cluster compactness and regulate yield in high-yielding varieties. This study aimed to evaluate the impact of ED on the physiology and metabolism of Aragonez (syn. Tempranillo) berries along the ripening period. The experiment was set up in 2013 at a commercial vineyard located in the Lisbon winegrowing region.

Lately several works highlighted the capacity of grape cell-wall material (CWM) to interact with proanthocyanidins (PA), indicating its potential use as fining agent for red wines.1–4 However, those studies were performed by using purified PAs and very high doses of CWM (almost ten-fold higher than those used in wine industry for other commercial fining agents). The present study focuses on the applicability of CWM from Cabernet sauvignon pomace as fining agent for red wines under real winery conditions. Grapes of cultivar Cabernet sauvignon were harvested at three different maturity levels
(unripe, mature, and overripe) and used for red winemaking. The pomace of such vinifications were used as source of CWM, and applied into red wines at two different concentrations: 0.2 g/L and 2.5 g/L.

A multidisciplinary approach aiming at studying the grape-growing areas also referred as “Terroir” was initiated a few years ago in Switzerland.