Evaluation of primocane-fruiting raspberry ( <i>Rubus idaeus</i> L.) cultivars in Estonian climatic conditions

Abstract During the three-year period from 2022 to 2024, five primocane-fruiting raspberry cultivars (‘Delniwa’, ‘Enrosadira’, ‘Jantar’, ‘Poemat’, ‘Polka’) were evaluated at the Polli Horticultural Research Centre of the Estonian University of Life Sciences, situated in southern Estonia. This study aimed to assess the traits of yield and fruit quality indicators of these selected cultivars, as well as their resistance to abiotic stress factors (temperature fluctuations and precipitation variability) and their adaptability to Estonian climatic conditions. As a result of the study, the most suitable raspberry cultivar for cultivation in Estonian conditions was identified among these cultivars. The study revealed significant differences between cultivars. The Polish cultivar ‘Poemat’ performed most consistently and proved to be well-adapted to Estonia’s climate. In contrast, the Italian cultivar ‘Enrosadira’ had the most fluctuating yields year-to-year, implying it’s more sensitive to varying weather conditions. The low yield of ‘Polka’ in the first year of observation, which constantly decreased in successive years, showed that this cultivar is not suitable for the Estonian climate conditions. Among the cultivars tested, ‘Delniwa’ from Poland showed the highest ratio of total soluble solids to total acids in juice, indicating the best taste characteristics. The study highlights the cultivar ‘Poemat’ among the evaluated raspberry cultivars as the most promising for Estonian growers due to its stable yield and good adaptability to climatic conditions. The study results provide practical knowledge for selecting parent cultivar plants in raspberry breeding and planning plantations in the Baltic region.