This paper aimed to study the adaptation of a crop to the specific climatic conditions of southern Romania, Pitești-Mărăcineni, Romania, in terms of the phenology of two chokeberry (Aronia melanocarpa) cultivars (‘Melrom’ and ‘Nero’). The BBCH (Biologische Bundesantalt, Bundessortenamt and Chemische Industrie) scale was used for phenological observations. The recorded data were statistically processed, calculating the average onset time and duration of fruiting phenophases and dormancy duration, average air temperatures, total solar radiation, and the cold and heat accumulation. Bud swelling was registered between 28 January and 8 February, budburst occurred starting on 3 March, while flowering began in stages, between 15 April and 1 May, and was completed between 27 April and 14 May. During the 154 days of 53–87 BBCH, the average air temperature, 16.1 °C, ranged between the extremes of −6.1 and 36.8 °C. The onset data and spring–summer phenophases were mainly related to the minimum air-temperature oscillations. The flowering timing shortened as the maximum temperature and total solar radiation increased. The relation between the environmental factors and the flowering strategy indicates the A. melanocarpa as a species adapted to the temperate continental climate of southern Romania.

Biochemical changes that undergo during the harvest season in 2020 (between 28 July and 11 September) were evaluated by a comparative study of two Aronia cultivars. The experiment was conducted at the Research Institute for Fruit Growing Pitesti, Arges County, Romania, on ‘Melrom’ and ‘Nero’ cultivars. Dry matter, total soluble content, pH, vitamin C, and biologically active components such as anthocyanins and phenolics variations were assessed from 28 July to 11 September 2020, for berries harvested every five days. ‘Melrom’ cultivar berries had significantly higher dry weight content, 251.43 g kg-1. ‘Nero’ showed a significantly higher vitamin C (1.87 g /kg-1 DW), total anthocyanins content (29.71 g cyanidin 3 – glucoside kg-1 DW), and juice pH (3.87). As harvest time main effect over the two cultivars taken together, dry weight, anthocyanins, total soluble content, and juice pH content increased significantly during the harvest season with 43.32%, 54.10%, 36.33%, and 17.98%, respectively, whereas significant losses of vitamin C, by 26.21%, and total phenolics compounds, by 27.90%, were recorded. Overall, early harvested fruits contained higher levels of moisture, vitamin C, and phenolics compounds, although the last crops provided less acidic fruits, with higher total soluble solids and anthocyanins content.