Value of Hordeum vulgare L. genotypes in terms of yield and its stability
Our purpose was to determine the value of spring barley (Hordeum vulgare L.) cultivars and lines in terms of yield and its stability. The GGE biplot analysis of competitive cultivar trial data was used. Due to the GGE biplot, the relationships between the barley cultivars and lines under investigation with the environment (years of their cultivation) were visualised. The mega-environment of 2018 and 2020 was the most optimal one for yields from the cultivars, especially Grace, Amil, Troian and Talisman Myronivskyi, while the 2019 environment for Avhur, Margret and Khors. The GGE biplot ranking graphically described the genotypes by average yield and its stability over the three years: Grace, Margret, Amil, Troian, Datcha, Avhur, Khors, Ahrarii, Talisman Myronivskyi and Herkules were high-yielding cultivars; naked cultivars Merlin, Gatunok and Akhiles gave the lowest yields; Grace, Gladys, Gatunok, Yavir, Kontrast and Khors were highly stable cultivars; Amil, Avhur, KWS Bambina and Rezerv were low stable. Of the high-yielding cultivars, Grace and Khors were the most stable ones. The GGE biplot also visualised the comparison of the genotypes with the hypothetical ‘ideal’ genotype by the highest ‘breeding value’: Grace was the best (5.43 t ha–1), Troian was the second best (5.31 t ha–1), followed by Margret (5.27 t ha–1), Avhur, Ahrarii, Krechet and Herkules (5.00–5.22 t ha–1). As a conclusion of the identified patterns, we established the practical and breeding value of the high-yielding and stable cultivars, Grace (5.43 t ha–1) and Khors (5.22 t ha–1), for conditions of different years, as well as the high-yielding and highly responsive cultivars, Amil (5.37 t ha–1) and Avhur (5.22 t ha–1), for the most optimal growing conditions.