Development of high-yielding varieties of soft winter wheat in the conditions of the southeastern Steppe of Ukraine

Topicality. One of the conditions to increase stably the soft winter wheat yield is plant breeding with high plasticity and resistance to adverse environmental factors, pests and diseases. Issues. Development of new high-yielding varieties with higher resistance to adverse weather conditions is important to increase crop produc-tivity. Aim. To create the initial material and high-yielding varieties of soft winter wheat in conditions of insuffi-cient soil moisture in the southeastern Steppe of Ukraine. Materials and methods. The research was conducted according to B. Dospekhov's method of field experience. The research was conducted in the 2017–2020 on the SE Research Farm Zaboishchyk of Donetsk State Agricultural Research Station NAAS at the Rozlyv village, Volnovakha district, Donetsk region. The field trials were conducted in the selective crop rotation of the Donetsk State Agricultural Research Station. The predecessors were black fallow and corn for grain. Research methods: hybridological, field, laboratory, mathematical and statistical methods. Results. According to the research results, it was found that the 77 numbers selected from hybrid combinations were left in the control nursery for further study. Among them were three numbers hk 363, hk 353, hk 403 which largest exceeded the standard by 14.1–19.7%. There are 42 numbers studied in a small competitive variety trial. It was determined that 15 hybrid combinations were the best than the standard (Donetska 48 variety) by 0.03–1.57 t/ha. In the competitive variety trial, 21 winter wheat cultivars after black fallow, and 25 cultivars after maize for silage were studied. According to yield, the best hybrid combinations after fallow were hk 4, hk 863/2, hk 716/1, which exceeded the standard Donetsk 48 by 0.41–0.51 t/ha, and after maize for silage, the best hybrid combinations were hk 321, hk 363, hk 318, in which the increase to the standard yield was 0.39-0.47 t/ha. According to the grain yield, the best varieties in the ecological variety trial were Bohynia, Popeliushka, Dyvo donetske, Oberih Myronivskyi, Yuzovska, Ihrysta, Peremoha, Patriotka, which exceeded the Donetsk 48 standard variety by 0.35-0.68 t/ha. Conclusions. It was determined that the development of new high-yielding varieties of soft winter wheat will increase productivity due to their adaptability for growing conditions in the southeastern Steppe of Ukraine. According to the analysis of the research results, the steppe ecotype varieties demonstrate a significant advantage on all the studied indicators; they better realize their genetic potential in specific soil and climatic conditions. Key words: breeding, winter wheat, hybridization, variety, yield.