The dissertation presents a theoretical generalization and practical solution of an important scientific problem of developing and improving the fundamentals for regulating the yield of innovative wheat varieties on the adaptive principles of crop cultivation, which will ensure stable and economically feasible production of high-quality seeds, taking into account the changing weather conditions of the central and the north-eastern part of the Forest-Steppe of Ukraine.
The innovative path of crop breeding development involves the creation and rapid implementation into production of high-yielding wheat varieties adapted to cultivation conditions with improved grain quality. One of the most unresolved issues is the effective utilization of late-harvested preceding crops; their relative part has increased because of the disruption of traditional agricultural systems. In the conditions of continuous resource growth and economic development in the post-war period, the problem of stabilizing wheat yield and grain quality will acquire significant relevance, which is what our research was aimed at, the priority and relevance of which are caused by the objectives of the institution's scientific programs.
For the first time in the conditions of the central and north-eastern parts of the Forest-Steppe of Ukraine, the specific features of productivity elements of winter wheat varieties: Triticum aestivum L. (MIP Fortuna, MIP Yuvileina, MIP Lada, Avrora Myronivska); Triticum durum Desf. (MIP Lakomka) and seed qualities were determined depending on two preceding crops (sunflower and soybean) and two sowing dates (September 25th and October 5th). The study revealed peculiarities in formation of yield and grain quality indicators of winter wheat after sunflower and soybean as preceding crops under different sowing dates. The experimental data demonstrated the influence of factors on the variation of varieties in terms of yield, grain quality indicators, seed infection, and sowing qualities. The study characterizes the part in sum square for the varieties, hydrometeorological conditions, preceding crops, sowing dates, and their interaction in formation of yield and grain quality indicators of winter wheat in two parts of the Forest-Steppe of Ukraine. The yield components and grain quality indicators primarily determined by genotype in comparison to other influencing factors were defined for the efficient winter wheat seed growing. Methodological approaches for identifying winter wheat varieties with regard to yielding capacity, yield components, grain quality indicators, seed infection of pathogens, and sowing properties of seeds were improved based on their response to preceding crops and sowing dates in the central and north-eastern parts of the Forest-Steppe. The positions regarding a significant increase in the realization of the genetic potential of innovative varieties of Myronivka breeding through the studied elements of cropping practices and hydrometeorological conditions and their influence on the formation of yield, grain quality indicators, seed sowing properties, and seed infection in two parts of the Forest-Steppe of Ukraine were elaborated. The economic efficiency of seed production technology for varieties sown at optimal and optimal late dates after sunflower and soybean preceding crops was justified. The best optimal sowing dates after sunflower and soybean preceding crops to achieve maximum yield in combination with superior grain quality indicators, seed sowing qualities, and grain infection development were identified in the conditions of the central and north-eastern parts of the Forest-Steppe.
