Ecological Plasticity, Yield, and Grain Quality of Different Soybean Varieties under Conditions of Kursk Oblast

The purpose of the research was to select the most promising soybean varieties for the conditions of Kursk oblast on the basis of the results of the assessment of their environmental stability and plasticity, the yield, and grain quality. The research was performed in a field experiment on typical heavy-loamy chernozem (Kursk oblast, Kursk raion) in 2020–2022. The authors studied 26 soybean varieties from five breeding centers. The HTC in the growing seasons of soybeans was 0.78 in 2020, 1.20 in 2021, and 1.33 in 2022. The ecological plasticity was the greatest (b_i=2.01–2.91) for the varieties Farta, Kioto, Avanta, Sparta, Kofu, Zusha, Shatilovskaya 17, and Kassidi with the yield of 2.17–2.64 t/ha and the lowest for the variety Bara (b_i = 0.44) with the yield of 1.90 t/ha. All the studied varieties were characterized by high ecological stability under conditions of Kursk oblast ( \(S_{i}^{2}\) = 0.01–0.65), and the varieties Elana and Arleta were the most stable ( \(S_{i}^{2}\) = 0.01). The best homeostaticity was typical for the varieties Bara (Hom = 14.29), Opus (Hom = 10.70), Irbis (Hom = 8.58), and Barguzin (Hom = 7.65). According to the parameter of agronomic stability, all the studied varieties were suitable for growing under the conditions of Kursk oblast (As > 70%). The varieties Bara, Opus, Irbis, and Barguzin were characterized by the greatest agronomic stability (As = 98.7–97.1%). The mean yield over the years of research was the highest for Nordika (2.54 t/ha) and the lowest for Kazachka (1.93 t/ha) among early-ripening varieties. Among the middle-early varieties, the grain yield was the highest for the variety Kofu (2.61 t/ha). The yield of the other varieties of this group of ripeness (Zusha, Slaviya, Kioto, Kassidi, and Amadeus) was lower than that of Kofu by 0.19–0.48 t/ha. The highest protein content in grain was recorded for Khana (45.9%) among early varieties and for Amadeus (45.6%) among middle-early varieties. Early varieties Nordika, Khana, Opus, and Osmon’ (the yield was 2.34–2.54 t/ha), middle-early varieties Kioto and Kofu (2.42–2.61 t/ha), and ultraearly ripening variety Bara of early harvesting may be recommended for the conditions of Kursk oblast.