Nut crops collection of "Ustymivskyi" dentrological park

Abstract

Aim. The aim of the work is to characterize the diversity of nut crops in terms of the efficiency of introduction in the conditions of the southern forest-steppe of Ukraine. Results and Discussion. In the collection of tree and shrub species of the State Dendrological Park "Ustymivskyi" numbering 472 species, nut crops are represented by more than 120 species. These include fruit species of temperate and subtropical zones from different botanical families. The climate in the area of the park is moderately continental with unstable humidity, frequent snowless winters with sharp fluctuations in air temperature. Dry winds are 2-3 times a year. The amount of precipitation is 254-777 mm per year. In the spring-summer period, there are periods without rain (up to two to three months). As a result of the study, the species and forms promising for introduction in such conditions have been identified. These are representatives of the genus Juglans: J. mandshurica Maxim. (Manchurian walnut), J. cinerea L. (gray walnut), J. nigra L. (black walnut) and J. regia L. (walnut). Corylus colurna (bear hazelnut) showed exceptionally good growth and abundant fruiting. However, in the last 10 years, the trees have become dry top and dry. Shrub species C. avellana (its forms 'Purpurea', 'Laciniata') and C. pontica C. Koch. turned out to be more adapted to climate change. The endemic steppe species Amygdalus nana L. (steppe almond) can be recommended in crosses when breeding for winter hardiness and an increased content of the alkaloid amygdalin (up to 4.5%). A. triloba Ricker. (almond three-bladed, regular and terry forms) is used as a decorative type. However, due to excessive disease damage (cercosporosis, orange spot, curly leaves, burns), plants lose their decorative effect. Repeated attempts to introduce into the collection such species as Carya alba (L.) C. Koch. (pignut hickory), Pterocarya pterocarpa (Michx.) Kunth ex Iljinsk. (caucasian wingnut), Fagus sylvatica L. (common beech) and Castanea sativa Mill. (sowing chestnut) were unsuccessful: the plants quickly died. Success has been achieved in the introduction and distribution of Xanthoceras sorbifolium and Ginkgo biloba in the forest-steppe and steppe zones. Conclusions. It is recommended to introduce walnut crops isolated as a result of the study into the range of plants used in landscaping, to create perennial plantations on lands unsuitable for agricultural production.