Tyshchenko A. Theoretical aspects and practical results of increase of productivity of alfalfa on the basis of selection achievements and varietal agrotechnics in the south Ukraine

Object of research: regularities of formation of indicators of adaptability of selection samples of alfalfa with high fodder and seed productivity at different ecological gradient; establishing their manifestation by combining methods of quantitative and visual assessment; formation of seed productivity depending on technological agricultural methods. The aim of the study is to theoretically substantiate the manifestation of adaptive traits and the formation of forage and seed productivity of new alfalfa source material in different ecological gradients, selection of the best high-yielding with high adaptability, resistant to adverse abiotic environmental factors and practical implementation of scientific approaches in Ukraine. Methods - field, mathematical-statistical, computational-comparative, abstract-logical and systems analysis. Results. Differentiation of alfalfa breeding material by drought resistance on the basis of use of indices and parameters of adaptability is carried out. The populations of alfalfa for fodder use of different types of orientation were selected: variety Elegy of intensive type, population M.g. / CP-11 is plastic, populations of M.g. / PP, LR / H, Ram. d. and M.agr. / C. stable. During the research period, three varieties of alfalfa were co-authored: Angelica (2015), Elegy (2018), Louise (2020), which combine high forage and seed productivity. The novelty lies in the theoretical generalization and solution of the current scientific problem of developing the scientific basis of alfalfa breeding for high fodder and seed productivity, adaptability through the integrated use of modern methodological approaches. The scientific value of expanding the genetic diversity of alfalfa source material, scientific provisions for establishing the level of adaptive and basic economic traits, their relationships, the allocation of new sources for selection on the basis of yield, adaptability and resistance to abiotic environmental factors in southern Ukraine. Sector – agriculture.