Ecobiological features of the Actinidia (Actinidia arguta (Siebold & Zucc.) Planch. ex Miq.) cultivars plants development in the conditions of the Northern Steppe of the Black Sea region

Abstract

Aims. Theoretical and experimental substantiation of the introduction of Actinidia plants to the natural and climatic conditions of the northern steppe of the Black Sea region of Ukraine. Methods. Biometric, comparative morphological, and statistical. Results. Three-year studies established the dates of the phenological phases of two forms: female and male French and domestic selection. In general, the onset of the main phenological phases of plant forms (cultivars) of Actinidia and their development in the process of organogenesis depended on the weather conditions at the beginning of the growing season. According to observations of the duration of phenological phases of plants, it was determined that female forms begin flowering 7 days earlier than male forms and bloom three days longer. Actinidia plants react negatively to low air temperatures in the early stages of organogenesis. Thus, the temperature at night on April 2, 2020, dropped from -2 to -5 ^oC and on the night of April 21, 2021, to minus 1 ^oC, which led to the freezing of young shoots and flower buds of both plant forms and to crop losses in these years. It was established that the biological maturity of the fruits of the studied culture begins in the second decade of September. Their full ripening was recorded at the end of the second decade — at the beginning of the third decade of the specified month. The duration of the growing season depended on the weather conditions of the year, as did the productivity of the plants. Berries in all years of research were characterized by high taste qualities, which were at the level of 8 points in the tasting evaluation. The resistance of plants of both forms and cultivars to pests and diseases in the 2020–2022 seasons was high, which is probably due to their absence in the new environment. Conclusions. Cultivars of Actinidia plants, grown in the natural and climatic conditions of the northern steppe of the Black Sea region of Ukraine, are adapted to the area of introduction and deserve further introduction into production.