Agronomic variability of the most important Croatian red cultivar Plavac mali (Vitis vinifera L.)

Representative samples of old mother vines (30-140 years old) of cv. 'Plavac mali' (Vitis vinifera L.) have been collected from the whole Dalmatian area based on their phenotypic diversity. More than 100 samples were planted into a homogeneous plantation and characterised based on ampelographic characteristics in order to identify their agronomic variability. The most important agronomic traits were evaluated during two years of vegetation on 63 clonal lines (clone offspring of six vines from each selected vine) that were planted in the homogeneous vineyard (ex situ collection). Significant variability was observed in the yield components, dimensions of bunches (shape, density, length, width and mass), and composition of the must (sugar, total acidity, pH, total polyphenols and total anthocyanins). The results show a significant degree of variability of the agronomic traits of cv. 'Plavac mali' and the possibility of their improvement by individual clonal selection.