Fruit Size and Main Chemical Properties of European Plums (Prunus domestica L.) as Influenced by Grafting on Seedlings of Commercial Cultivars

During three consecutive years we investigated the influence of seedlings of Myrobalan, Stanley and Green Gage as rootstocks on main fruit physical and chemical properties of four European plums (‘?a?anska Rana’, ‘?a?anska Lepotica’, ‘?a?anski ?e?er’ and ‘Stanley’) grown under ecological conditions of ?a?ak (Serbia). Results showed that significant differences in most properties such as fruit weight (FW) and its size and shape, stone weight (SW), soluble solids content (SSC), titratable acidity (TA), total sugars (TS), ripening index (RI) and sweetness index (IS) were examined among rootstocks. Influence of these rootstock on flesh rate (FRa) or flesh/stone ratio in cultivars evaluated was not significant. In the case of ‘?a?anska Lepotica’, rootstocks had not capacity to change sphericity (φ) and TA. Seedlings of Myrobalan improved only SW in ‘?a?anski ?e?er’ and TA in all cultivars. In all other cases this rootstock decreased values of evaluated traits. The best fruit physical and chemical properties of plums were achieved by seedlings of Green Gage and Stanley alone or alongside. Despite the higher TA contents in fruits on Myrobalan and its tendency to induce higher SW in some cultivars, the smaller sized fruits together with the less attractive fruit shape resulted in a non-interesting rootstock for plums in our growing conditions. Interesting and positive behavior of cultivars were found for quality parameters when grafted on seedlings of Green Gage and Stanley, respectively.