South Africa Wine Research Projects

2. VITICULTURE RESEARCH NEW PROJECT

IN-FIELD QUANTIFICATION OF GRAPEVINE KEY ANALYTES USING PORTABLE INFRARED SPECTROSCOPY DEVICES

SAGWRI JT 24-01 Dr Jose Luis Aleixandre-Tudo, South African Grape and Wine Research Institute, Stellenbosch University Start date: 2024

AIM AND INDUSTRY RELEVANCE: Knowledge of key analyte levels in the grapevine growing season is hindered by analytical limitations such as time-consuming protocols, expensive analytical procedures, and limitations of the technology for direct measurement in grapevine tissue. Furthermore, spectroscopy calibrations are not optimised for in-field conditions. This project aims to supply optimised prediction calibrations for in-field direct quantification of important analytes from grapevine organs, such as shoots, leaves and berries. The target analytes are carbohydrates, nitrogen and amino acids. Ambient variability will also be incorporated into the models to optimise prediction accuracies. The Chenin blanc vineyard, which is part of the research project “Premium and profitable Chenin blanc wines,” and the Flagship Project 3 vineyard will be the sources used to acquire the required variability for calibration optimisation. Three different experiments will be conducted under this objective. • The Flagship Project 3 vineyard’s nutrient content will be monitored and assessed during a growing season using optimised calibrations. • Amino acid development will be monitored in the Chenin blanc experimental vineyard during grape ripening. • Lastly, the effect of the nutrient content on the take percentage of grafting material will be assessed. In this instance, a sample set containing materials with varying nutrient content levels will be utilised to demonstrate the concept. If successful, the project’s outcome will benefit the nursery industry’s supply chain due to the potential optimisation of plant material. Overall, it will improve the quality of the plant material, grapevine development and grape and wine quality.

SOUTH AFRICA WINE RESEARCH 2024

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