CHARACTERISTICS OF GROWTH AND NUTRITION OF APPLE SEEDLINGS (THE ORLIK VARIETY) DEPENDING ON CULTIVATION METHODS AND SUBSTRATE COMPOSITION
In connection with the development program, the horticultural industry faces the challenge of increasing planting space. Solving this problem requires an increase in the production of planting material. Apple is the main fruit crop. In recent years, the production of planting material of fruit and ornamental crops in containers has been growing. In this regard, the task of developing elements of the technology of seedling production in containers has become especially urgent. The authors have studied the influence of cultivation methods and substrate composition in container cultivation on the development of seedlings and specific features of providing Orlik apple seedlings with the main nutrition elements. The authors have tested various options for the substrate to be used in containers: the Control sample (seedlings in a new open ground plantation); peat moss + sand in the ratio; peat moss + agroperlite; peat moss + sand + humus; peat moss + sand + vermicompost. All substrates have been aligned by the content of nutrients with mineral fertilizers calculated for each variant individually. The regularities of the effect of substrate composition on the growth of seedlings, and the content in leaves of nitrogen, phosphorus and potassium. The optimum composition of substrate for growing seedlings of apple trees in containers has been thus revealed. On the basis of the conducted research it has been established that the studied soil samples provide the necessary level of mineral nutrition of apple seedlings. According to the sheet diagnostics data, no significant deviations from the optimal values in the content of nutrients in tree leaves have been observed. The best development of annual amount of the growth of seedling shoots has been observed when applying a substrate consisting of peat and agroperlite in the ratio of 3:1.