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Relevance. The article presents the results of a three-year study of the economic and biological characteristics of the Stanley plum variety (growth and development of plants, the time of fruiting, productivity, yield, marketable qualities of fruits) when grown on medium-sized clonal rootstocks Evrika-99 and Druzhba, bred at the Crimean experimental breeding station named after N.I. Vavilov, in the acutely arid conditions of the Astrakhan region.Methods.The purpose of the research was to study the influence of medium-sized clonal rootstocks on the production process of the Stanley plum variety in the natural and climatic conditions of the Astrakhan region and to substantiate the possibility of their use for laying intensive plum plantations in the arid conditions of the Northern Caspian Sea.Results. In the course of the research, the influence of the rootstock genotype on the main indicators of productivity was revealed: precocity, yield, commercial qualities of fruits. The early fruiting of the variety was most influenced by the medium-sized rootstock Evrika-99, on which already in the first year of growth in the garden 60-80% of plum trees were noted to bloom. Among the studied rootstocks, the highest rates of yield increase in the Stanley variety were noted on the medium-sized rootstock Evrika-99, in combination with which the variety was characterized by the maximum values of the average yield of 7.6 t/ha, with the values of this indicator on the rootstock Druzhba — 6.7 t/ha , which is 11.8% higher. According to the marketability of the fruit, the rootstock Druzhba was noted, the average weight of which was 48.2 g, which is 18.1% more than on the stock Eureka-99 (40.8 g). In the extremely dry conditions of the Astrakhan region, the Stanley variety is recommended to be grown in an intensive garden on the rootstocks Evrika-99 and Druzhba, which ensure regular and stable yields.

The article presents the results of the influence of out-root fertilizing on the parameters of the leaf surface of varieties of domestic plums in arid conditions of light chestnut soils of the Northern Caspian. The study was conducted at the experimental site of the Caspian Agrarian Federal Scientific Center of the Russian Academy of Sciences. The pilot site was laid in 2014. Records and observations were carried out in 2019-2021. The research materials were varieties of plums Kuban early, Renclod Altana, Burbank and out-root leafy fertilizing preparations Master, Aquarin, Ultramag boron and Ultramag calcium. The leading indicators of the production process include the leaf surface area, photosynthetic capability and the net efficiency of photosynthesis, which show a close direct relationship with yield. Developing an optimal leaf surface area is an essential component of the technology and is vital for effectively absorbing light energy for photosynthesis. Analysis of the effects of micro-fertilizers Aquarin and Ultramag boron at the same time Ultramag calcium on the parameters of the leaf surface of plum trees showed that the most responsive varieties for the use of this drug were the Kuban early and Burbank varieties. The Renkloda Althana variety responded better to the action of the Master preparation. The largest leaf area formed on 1 ha, relative to the control, differed in the variant with the combined use of Aquarin, Ultramag boron and Ultramag calcium, which amounted to 3671 m2. Among the varieties, the Burbank variety was characterized by the largest leaf area formed per 1 ha, in which this indicator was 3080 m2.