Ecological plasticity, stability, and nitrogen-fixing capacity of edible bean cultivars in the Forest-Steppe of Ukraine

The purpose of this study was to investigate the influence of climatic conditions of the research years on changes in productivity and environmental plasticity and stability of edible bean cultivars. Furthermore, the study investigated the nitrogen-fixing potential of edible bean cultivars for the biologisation of agriculture. The study was conducted in the conditions of the educational and production department of the Uman National University of Horticulture during 2020-2022, using nine cultivars of edible beans. Standard methods of statistical analysis were used to study the parameters of adaptive variability. As a result of the comparative study, the characteristics of various parameters of the adaptive potential of edible bean cultivars were established by the following traits: the onset of the technical ripeness phase: Bianco and Extra Grano Violetto – 78 days. The cultivars Windsor Broad (16.42 t/ha), Bianco (13.73 t/ha), and Svitiaz (11.51 t/ha) stood out in terms of yield and adaptability in the technical ripeness phase, the cultivars Bacchus (1.92 t/ha) and Svitiaz (1.90 t/ha) – in terms of yield and adaptability in the biological ripeness phase; cultivars with high protein content in immature grain: Karmazin (12.77 g/100 g), Windsor Broad (13.51 g/100 g), Bianco (14.30 g/100 g), and Green lowland (14.43 g/100 g); cultivars with high nitrogen-fixing capacity: Ukrainian Sloboda (67.7 kg/ha), Windsor Broad (71.0 kg/ha), and Extra Grano Violetto (75.7 kg/ha). The results of the statistical analysis showed a significant influence of environmental conditions on the formation of productivity indicators of edible bean cultivars and a greater dependence on environmental conditions (CVA = 10.40-82.7%) than on the genetic component (CVG = 5.76-39.7%). The data suggest a tendency for yields to be inversely related to yield stability, with low-yielding cultivars showing stability and high-yielding cultivars showing instability. The presented findings suggest an idea of the change in the productivity parameters of edible beans under contrasting weather conditions, which makes it possible to identify cultivars with high productivity for food purposes and with a higher proportion of high-protein and energy-rich consumer products. Cultivars with increased nitrogen-fixing capacity were identified, which will help reduce the use of synthetic fertilisers