Phenological traits, yield and fruit quality of plum cultivars created at the Fruit Research Institute in Čačak, Serbia

Phenological traits, yield and fruit characteristics of ten plum cultivars bred at the Fruit Research Institute in Čačak were studied in the region of Belgrade in the period of four years (2012-2015). Average time of flowering of tested cultivars was in the first half of April. The earliest flowering was recorded in ‘Čačanska Rana’ and ‘Valerija’, at the latest in ‘Zlatka’. The range of fruit maturity was about 2.5 months, from June 24 (‘Boranka’) to September 6 (‘Pozna Plava’). The average yield per tree was the lowest in ‘Boranka’ (7.8 kg) and the highest in ‘Čačanska Najbolja’ (23.6 kg). The cultivars ‘Čačanska Rodna’, ‘Nada’ and ‘Valerija’ stand out for high cumulative yield efficiency (0.34 to 0.36 kg/cm2). Fruit weight was the lowest in the cultivar ‘Mildora’ (23.9 g), and the highest in the cultivar ‘Čačanska Rana’ (51.3 g). The cultivar ‘Zlatka’ is distinguished by a small stone (weight of 0.83 g and the share in a fruit weight of 3.1%). The cultivars ‘Mildora’, ‘Pozna Plava’ and ‘Čačanska Rodna’ are characterized by high soluble solids content (19.8-21.0%), while the cultivars ‘Mildora’ and ‘Nada’ are characterized by low acid content (0.47-0.48%) and a very sweet taste. The highest scores for fruit appearance obtained the cultivars ‘Čačanska Najbolja’, ‘Čačanska Rana’ and ‘Nada’, and for taste the cultivars ‘Nada’, ‘Mildora’ and ‘Čačanska Rodna’