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The aim of the conducted research was to study the dynamics of nitrogen content in various organs of apple trees (spurs, annual shoots, branch wood) in the fruit-bearing orchard in different periods of the growing season. Nitrogen content was monitored at the end of the growing season (November), during the beginning of the growing season (April) and during the period of active fruit growth (July). The research was carried out in an intensive apple orchard in the Tambov region on the next varieties: ‘Antonovka Obyknivennaya’, ‘Zhigulevskoye’, ‘Orlik’, ‘Spartan’, ‘Bogatyr’, grafted on rootstock 62-396. The nitrogen content was determined in dried and crushed plant material according to the Kjeldahl method. As a result of research, it was found that the high content of nitrogen in the wood of apple trees was recorded in the autumn period, in the future the level of nitrogen decreased and reached the minimum value by the spring. In summertime, the content of nitrogen in 2-4 and 5-6 years old wood of all studied varieties increased in comparison to autumn and spring. The largest content of nitrogen was found in wood of ‘Zhigulevskoye’ variety was 0,82 % (2-4 years old wood) and 0,86 % (5-6 years old). This is more than in autumn on 0,30 % and 0,24 %, and in spring on 0,39 % and 0,35 % respectively. Based on the data obtained, the content of this nutrient in the apple tree wood in the autumn could be corrected by the application of nitrogen fertilizers during growing season, which directly affect the accumulation of reserve substances and tissue aging. It makes a positive impact on the development of the future crop and the preparation of trees for the winter.

In the literature there is very little information about fruiting, growth activity of various hawthorn species. Therefore, a comprehensive study of hawthorns is necessary in order to improve the health and living conditions in cities, as well as to obtain the highest quality harvest of fruits with valuable traits. The article presents data on the development of phases of vegetation of elite hawthorn seedlings using natural, improved vase-like and sparse-tiered crown forms in the Central Black Earth Region. It was found that the greatest annual growth of shoots was observed in the elite seedling Michurinsky Dessertniy with an improved vase-like crown shape. The largest fruits were obtained from an improved vase-like crown shape of hawthorn trees, (Karamelka, 3.7 g; Tambovskiy Volk, 3.4 g).

This research explores the compactness of apple varieties and forms with different types of crown. Orchards on semi-vigorous rootstocks with density and high density planting systems are cost-effective in modern horticulture. For making such gardens, it is necessary to have trees with special compact crown shape. They ensure the high-quality fruits production, meeting the requirements of world standards. To date the most perspective apple varieties and forms for domestic intensive gardening from the rich gene pool of the Selection and Genetic Center of Federal State Scientific Institution «I. V. Michurin Federal Scientific Center» are identified. Varieties of folk domestic and foreign breeding took part in the creation of new genotypes. Apple varieties and promising forms (more than 160 genotypes), including from near and far abroad selection, were used as materials for crown features studying. We conducted our study by the following indicators: tree height, crown volume, “degree of compactness” and the shoot-forming ability. We found that the genotypes Sholokhovskoye, Zvezda Artemyeva, 25-7(11), 40-9(8), 36-8(21), 40-9(6), 8-7(72), 40-9(7), 36-8(17), 62-5(140) have optimal crown parameters. We recommend their use for industrial horticulture and further breeding to create restrained growth, low-volume crown, and a high degree of compactness varieties.

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