The ampelographic and physicochemical characteristics of Muskatell and Marsusa Sewda grapevine varieties

Abstract

This study investigated the ampelographic and physicochemical characteristics of three Vitis vinifera L. varieties cultivated at the National Viticulture and Oenology Centre in Buskett, Malta: Muskatell, Marsusa Sewda 1, and Marsusa Sewda 2. A total number of twenty-four grapevine samples were analysed over two consecutive growing seasons (2024–2025). Morphological characterisation followed International Organisation of Vine and Wine (OIV) descriptors, with weekly observations recorded from pruning to harvest. Cumulative Growing Degree Days (GDD) were calculated to assess phenological development, with Muskatell, Marsusa Sewda 1, and Marsusa Sewda 2 reaching maturity at approximately 1,799, 1,910, and 1,929 °C.day, respectively. Muskatell produced compact clusters (OIV 204: 9) and globose green-yellow berries (OIV 223: 2) reaching 22.3 °Brix at harvest. Marsusa Sewda 1 bore dense blue-black clusters (OIV 204: 9) with broad-ellipsoid berries achieving 21.2 °Brix, while Marsusa Sewda 2 exhibited looser clusters (OIV 204: 3) and heavier seeds (OIV 242: 7), indicating improved aeration and fertility. Spectrophotometric and MP-AES analyses revealed total polyphenol contents ranging between 60–120 µg GAE/ml and dominant mineral elements of potassium, calcium, and magnesium across varieties, with minor iron and sodium concentrations. Statistical analyses (ANOVA, p < 0.05; PCA) confirmed significant varietal differentiation in cluster compactness, berry morphology, sugar, and polyphenolic accumulation. The integration of OIV descriptors, GDD progression, and biochemical data provides a robust framework for identifying, conserving, and valorising indigenous Maltese grapevine germplasm within Mediterranean viticulture.