Nitrogen isotope ratio (δ15N) as a tool to trace the major nitrogen source in vineyards

Yeasts serve as highly versatile tools in oenology. They do more than just perform alcoholic fermentation. Nowadays, yeasts from various species, naturally present in grapes, are selected for specific non-fermentative applications. For example, the use of selected non-saccharomyces at the early stage of winemaking has become a common practice to limit the growth of unwanted microorganisms. When inactivated, yeasts can be fractionated into soluble and insoluble fractions providing a wide range of benefits related to structural components or specific metabolites.

In this study macro and micro nutrients of plants (N = NH4 + NO3 , P, K, Ca, Na, Zn, Mn, Fe and Cu) were determined both in soil solution and bleeding sap and compared each other. Bleeding sap was collected from the nine varieties of grapevine Cvs. grafted on 5BB rootstock and grown in different soil conditions. For all varieties, plant nutrients content in bleeding sap as higher than in soil solution except for Ca and Na. While in soil solution Ca content was found at 10209 ppm, this value in bleeding sap was 49.20 ppm (Kozak Beyazy), 55.38 ppm (Trakya Ylkeren), 50.37 (Cardinal) and 74.27 ppm (Tekirdaô Çekirdeksizi) respectively. For the same varieties the Na values were as follows : 7.16 ppm (in soil solution) : 4.8, 3.23, 4.21,4.58 ppm (in bleeding sap) respectively. K content in bleeding sap was higher than in soil solution for a few varieties, and lower in some varieties. Traces of Fe and Cu were found in both media.

In the context of climate change, excessive bitterness and astringency in wines have become increasingly prevalent. While variety selection and viticultural practices offer long-term solutions, they require considerable time before yielding practical results. In contrast, fining remains an accessible and immediate tool for winemakers.

The content of 3-sulfanyl-1-hexanol and its acetate ester in wine is affected by a number of factors, including the concentration of its precursors S-3-(hexan-1-ol)-L-glutathione (G-3SH),

It is fundamental for wineries to know the potential yield of their vineyards as soon as possible for future planning of winery logistics. As such, non-invasive image-based methods are being investigated for early yield prediction. Many of these techniques have limitations that make it difficult to implement for practical use commercially. The aim of this study was to assess whether yield can be estimated using images taken in-field with a smartphone at different phenological stages. The accuracy of the method for predicting bunch weight at different phenological stages was assessed for seven different varieties.