Dynamics of nitrogen content in the branches of the apple trees

Abstract

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.