Behaviour of Japanese Plums in Atypical Environmental Conditions of Serbia: Tree Growth, Productivity and Fruit Quality Attributes

Abstract

Vegetative growth, yield, fruit quality attributes and antioxidant activity of ‘Angeleno’, ‘T.C. Sun’ and ‘Black Amber’ Japanese plum cultivars were studied over a 7‑year period after planting. The experiment was performed in the Prislonica village (Čačak, Serbia), on a sandy-loam and acidic soil and moderate climate. The cultivars were grafted on Myrobalan rootstock and grown under a high density planting system with 1250 trees ha−1. Significant differences in parameters evaluated such as tree vigour, productivity, fruit physical traits, chemical composition and antioxidant activity were examined between cultivars. The highest tree vigour (TCSA) was observed in ‘Angeleno’, final yield per tree in ‘Black Amber’ and cumulative yield and yield efficiency in ‘T.C. Sun’. In general, the best physical properties were found in ‘Black Amber’ and ‘T.C. Sun’. ‘Angeleno’ showed the highest soluble solids content (SSC), whereas ‘Black Amber’ had the highest titratable acidity (TA). ‘Angeleno’ and ‘T.C. Sun’ had similar and better ripening index than ‘Black Amber’. However, ‘Black Amber’ was the cultivar with the statistically higher total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (TAC) compared to the other two plums. The flesh rate (FRa) significantly and positively correlated with TA and TAC, whereas negative correlation was observed between SSC and TFC. The most important variables integrated in the first principal component (PC1) were yield per tree, FRa, flesh firmness, SSC, TA, ripening index, TPC, TFC and TAC, whereas PC2 explains TCSA, fruit weight and fruit shape index (sphericity).