Changes in physical properties of plum fruit (Prunus domestica L.) from physiological maturity to harvest maturity stage

Abstract

During 2017 differences in the physical properties of fruit at physiological and harvest maturity were evaluated in five plum cultivars (‘Čačanska Rana’, ‘Čačanska Lepotica’, ‘Čačanska Najbolja’, ‘Čačanska Rodna’ and ‘Stanley’ (control cultivar)) grown in high density planting system (HDP) under the environmental conditions of Čačak. In addition to recording the dates of the two maturity stages, the study involved measurement of fruit weight, three fruit linear dimensions (length, width, thickness) used for calculation of fruit volume and shape, and soluble solids content (SSC). Results showed that harvest maturity in the tested cultivars occurred 6.28 days after physiological maturity. The number of days from physiological maturity to harvest maturity varied from 2.5 in ‘Čačanska Rana’ to 9 in ‘Čačanska Lepotica’ and 9.5 in ‘Čačanska Najbolja’. During this period, fruit length increased by 6.94%, width by 7.93% and thickness by 7.69% on average. When analysed across cultivars, the highest increase in fruit length, width and thickness was observed in ’Čačanska Najbolja’ (13.66%; 17.75% and 16.19%, respectively). Fruit shape index did not significantly change between the maturity stages. The increase in fruit weight and volume was ranging from 11.44% and 7.50% (‘Čačanska Rodna’) to 42.68% and 30.23% (‘Čačanska Najbolja’). The lowest increase in SSC was found in ‘Čačanska Rana’ (6.26%) and the highest in ‘Stanley’ (12.32%).