Evaluation of semi-erect blackberry (Rubus subgenus Rubus) cultivars grown in Serbia

The main focus of our study was to investigate differences in ripening time, standard parameters of productivity (number of fruiting branches and fruits cane^-1, yield cane^-1 and yield bush^-1) and fruit quality (fruit weight, index of fruit shape, soluble solids content - SSC and titratable acidity - TA), and also of nutritional value (total anthocyanins - TACY and total phenolic content - TPC) of two introduced semi-erect blackberry cultivars 'Loch Ness' and 'Triple Crown', and domestic cultivar 'Čačanska Bestrna' as a prevailing one in blackberry plantations in Serbia. Results from this study showed that the earliest first harvest date was observed in 'Loch Ness' (June 26), whereas 'Triple Crown' was the most late cultivar (July 16). 'Čačanska Bestrna' exhibited consistently higher values for the parameters of productivity achieving significantly higher yields (5.94 kg cane^-1) in comparison to other studied cultivars. This cultivar is also characterized by the highest average fruit weight and index of fruit shape (9.67 g and 1.27, respectively). Significantly lower average fruit weight was recorded in 'Loch Ness' (5.65 g), whereas 'Triple Crown' had the lowest index of fruit shape (1.13) corresponding to conical form. 'Triple Crown' also exhibited the highest level of SSC (13.5%), followed by 'Loch Ness' (12.3%). 'Čačanska Bestrna' had significantly higher TA (1.57%) in comparison to the other cultivars. Regarding the nutritional value of studied cultivars, 'Loch Ness' ranked the highest in TACY and TPC (69.1 mg equivalent of cyanidin-3-glucoside 100 g^-1 of fresh weight and 14.8 mg equivalent of gallic acid g^-1 of fresh weight, respectively). In general, introduced cultivars 'Loch Ness' and 'Triple Crown' demonstrated better outer and inner fruit quality traits than the cultivar 'Čačanska Bestrna'. Furthermore, these cultivars could be considered as genotypes with enhanced consumer acceptability.