Assessment of introduction prospects of David Austin’s roses to the conditions of the Right Bank Forest-Steppe Zone of Ukraine

Abstract

Aims. The theoretical and experimental substantiation of the introduction of the roses originated by David Austin to the environmental conditions of the Right Bank Forest-Steppe Zone of Ukraine. Methods. Biometrical, comparative-morphological, and statistical ones. Results. Viability, growth, and development indices as well as ornamental qualities (tolerance for winter conditions, frost hardiness, drought resistance, complex disease and pest resistance, habit maintenance, flowering, coloration, shape of flowers, etc.) were analyzed for 18 rose cultivars of breeding by David Austin. The cultivars belong to the English Old Rose Hybrids, Leander Hybrids, and Leander Hybrids groups. The investigations were conducted between 2015–2021 on the introduction and exhibition plots of the NDP “Sofiyivka”. Evaluation of the prospects of introduction showed that 50% of the studied cultivars have a score of 41–43 points of 50, and they are totally promising for the introduction to the conditions of the Right-Bank Forest-Steppe Zone of Ukraine. The other 50% of cultivars have a score of 35 to 40 and may be considered promising ones. The average score was close in all three groups of cultivars and amounted to 39.0–40.2 points. The acclimatization number for 50% of the studied cultivars was 80–85 points out of 100 which means the good adaptation of the plants in the conditions of the Right-Bank Forest-Steppe Zone of Ukraine. For the other 50% of cultivars, the figure ranged from 65 to 75 points, which means a satisfactory adaptation of these plants. The average acclimatization number was 73.8 points for English Old Rose Hybrids, 78.0 points for English Musk Hybrids, and 80.0 points for Leander Hybrids. The total evaluation of ornamental qualities of David Austin’s English roses made 81–89 points of 100. The average value of this index was close in all three groups of cultivars and amounted to 85.3–85.6 points. Conclusions. The garden roses of breeding by David Austin grown in the environmental conditions of the Right-Bank Forest-Steppe Zone of Ukraine are adapted well in the introduction region and deserve to be introduced to production.