Assessment of Growth and Development of Representatives under the Conditions of Chestnut Soils

The growth and development of woody plants allow revealing the essence of their relationship with the environment. New conditions for growing plants primarily affect their growth and development, which is associated with the amount of heat and moisture. The aim of the research was to study the dynamics of growth and development of Gleditsia under new cultivation conditions (chestnut soils of the Volgograd region). In the arid zone of Russia, a comparative analysis of the species of the Gleditsia genus: G. texana, G. cassis, G. triacanthos, growing in the cluster dendrological collections of the Federal Research Center of Agroecology of the Russian Academy of Sciences (cadastre. № 34:34:000000:122, 34:34:060061:10; cadastre no. 34: 36:0000:14:0178). The analysis of long-term phenological observations at various temperature parameters of the environment was carried out. The optimal temperature for the beginning of active growth of shoots and its intensity were revealed. It was established that under the conditions of arid climate of the Volgograd region, the species of the Gleditsia genus are characterized by a spring-summer period of shoot growth (from the first decade of May to the third decade of July). Apical shoots start to grow earlier and finish it later than the lateral ones. At the time of cessation of growth in all species, the tops of the shoots dry up together with 2–3 leaves. Then comes the process of lignification of young shoots, contributing to their resistance under winter conditions. When comparing the data on the development of shoots of different Gleditsia species, no clear differences were found. Gleditsia triacanthos has the longest growing season (195 days) compared with the rest of the studied species. During the growing season, all Gleditsia species go through a full cycle of development, which indicates the success of their introduction, proving that the Gleditsia genus is a stable plant in chestnut soils. Gleditsia has no special generative shoots. The period from the beginning of budding to flowering depends on weather conditions (an increase in temperature to 28 °C slows this process down). In hydrologically favorable years, at an average air temperature of 21.5 °C, continuous flowering of plants is observed). The obtained materials are necessary for selection for landscaping, assessment of aesthetic and sanitary-hygienic properties, development and implementation of measures to protect green spaces from pests and diseases. Phenological observations have a huge role for forest reclamation.