EFFECT OF SOME PLUM CULTIVARS ON PRODUCTIVITY, COLOUR AND BIOCHEMICAL PARAMETERS ON THESE CULTURE IN NORTHERN REGION OF THE COUNTRY

Rezumat

The study aimed to evaluate the yield, fruit colour and biochemical characteristics of six plum cultivars grown in the north of the Republic of Moldova, under the conditions of the year 2026. The research was carried out in the ‘Agrofields’ enterprise plantation on the cultivars ‘Piteștean’, ‘Cacanska Najbolia’, ‘Empresso’, ‘Stanley’ (control), ‘Blue Free’ and ‘President’.
The trees were grafted onto Prunus cerasifera rootstock, planted at a distance of 5.0 × 3.0 m and trained into a high-volume mixed pyramid shape. The experiment included four replicates of eight trees each for every variety. The following parameters were determined: yield, average fruit weight, CIELAB colour coordinates (L*, a*, b*), soluble solids content (SSC), titratable acidity (TA), the SSC/TA ratio and vitamin C content. The average fruit weight ranged from 40.9 g for ‘Stanley’ to 58.7 g for ‘Empresso’. The ‘Cacanska Najbolia’ variety recorded the lowest number of fruits and the lowest yield (207 fruits/tree; 7.81 t/ha), and ‘Blue Free’ the highest values (728 fruits/tree; 23.39 t/ha). Negative values for the b* coordinate indicated a
blue component in the skin colour, whilst the pulp had a predominantly yellow component. SSC ranged from 15.91 to 20.64 %, TA from 0.79 to 1.51 %, the SSC/TA ratio from 12.41 to 23.11, and vitamin C from 9.32 to 12.47 mg per 100 g fresh weight. The results highlight distinct profiles of the cultivars in terms of fruit yield and composition. Under the studied conditions, ‘Blue Free’ had the highest yield, ‘Empresso’ had the highest average fruit weight and the highest vitamin C content, and ‘Stanley’ had the highest SSC/TA ratio.