Yakovenko R. Principles of the productivity increase of apple- and pear-trees under the optimized fertilization

The object of the study is repeated plantings of apple and pear trees. Soil from the garden. Fertilizer systems. The purpose of the research is to ensure high productivity and quality of fruits of non-irrigated apple and pear plantations of various varieties and rootstock combinations (with repeated cultivation on dark gray podzolized soil) using an optimized fertilization system during the age periods of the trees. Research methods: field (garden), vegetation, laboratory-field , laboratory and statistical. The novelty of the work consists in the established regularities of increasing the productivity of repeated plantings of apple and pear trees of strong and medium-growing varietal rootstock combinations with optimized fertilization at different age periods and the development of measures to mitigate the effects of soil fatigue in newly planted plantations with repeated crops. A different (than apple) response of pear on quince rootstock A to soil fertility, in particular, levels of nitrogen and potassium nutrition and the need for higher availability of soil with mobile compounds of these mineral elements for plantations of this culture, was determined. The dynamics of the humus content and indicators of the physicochemical properties of the soil under optimized fertilization of repeated plantings of apple and pear trees were established, as well as the neutralizing negative effect of organic fertilization of the previous garden on soil depletion. A significant weakening of the growth of two-year-old apple trees on dark gray podzolized soil was established after growing apple trees for 84 years. A method of accelerating the morphogenesis of fruit-bearing formations of pear in plantations on vegetative rootstock with foliar feeding with a complex of nutrients in certain periods of vegetation has been developed. An effective increase in the productivity of apple and pear replantings with optimized fertilization with high annual yields of quality fruits in different age periods of the trees has been established.