Abstract
<jats:p>Abstract. The results of research on the development of tree crown constructions of domestic breeding apple varieties in combination with a system for the use of biostimulants are presented. Research period: 2020-2025. Russians spindle crown training system has been improved with modifications of the Russian spindle with elongated shoots and the Russian spindle with shortened shoots in combination with green operations. In these unsupported training systems, the illumination of the crowns was the same in all tiers, which contributed to an even distribution of fruits and an increase in their yield by 11-13 %. The use of improved apple tree crown training systems in combination with a system of using amino acid-based biostimulators contributed to an increase in yield. More apple fruits were obtained from Orfey variety trees, the increase compared to the traditional Russian spindle training system was 68 %, from Margo variety trees was 52 %. An increase in the average fruit weight of the studied apple varieties during treatment with biostimulators was noted up to 32 %. The system of using biostimulators against the background of modified crown training systems contributed to the formation of a larger volume of fruits of the highest grade. The system of non-root treatments with a biopreparation based on amino acids Izabion on an Orfey apple tree was found to be the most effective. The volume of apples of the highest grade in the variant with treatment with Izabion at a dose of 4 l/ha against the background of a modified formation with elongated shoots was 86 %, 67 % was noted in the control variant of high-quality fruits. The developed agrotechnological practices for managing the productivity of apple trees of domestic varieties have influenced an increase in the content of vitamins C and P in apples, especially Orfey varieties. Keywords: apple tree varieties of domestic breeding, unsupported technologies, variety-oriented crown formations, crown illumination, non-root treatments with biostimulators, fruit crop productivity, yield</jats:p>