Agrobiological assessment of green bean varieties by adaptability, productivity, and nitrogen fixation

Beans should be studied as an ecological object that can be used to replenish the reserves of nitrogen compounds in the soil and increase its biological activity. The goal was to conduct scientifically based zoning of varieties and assess their adaptive and productive potential in terms of productivity and nitrogen fixation. The study was conducted in the training and production department of the Uman National University of Horticulture during 2020-2022, using six varieties common in production. Standard methods of genetic and statistical analysis were used to investigate the parameters of adaptive variability. The study of phenological changes showed that, depending on the variety, it takes from 54 to 67 days before the onset of technical ripeness, and the variation of this trait is 8%. The shortest period before harvesting green beans was characterised by the varieties Zorenka and Casablanca. The variation of the growing season before the onset of biological ripeness was in the range of 90-108 days (CV=6%). According to the indicator of attachment of the lower bean, suitable varieties for mechanised harvesting were identified – Zorenka and Casablanca. Analysing the parameters of adaptability of the “bean weight” and “yield” indicators, a stable variety was found – Fruidor and highly productive varieties of intensive type Paloma, Laura, Zorenka, and Casablanca. The most productive variety was Zorenkya – 12.7 t/ha, and the least productive – Fruidor – 1.9 t/ha. In terms of seed yield, the varieties Purpurova Koroleva, Zorenka, and Casablanca stood out, the yield of which was at the level of 2.22-2.89 t/ha, which is 30.8- 70.6% more than the standard. Analysing the dependence of the growth and development parameters of green bean plants, it can be seen that these traits depend more on the conditions (CVA, %) in which they were formed than on the genotypic component (CVG, %). The results obtained provide useful information on commercial and seed production, productivity and the nitrogen-fixing ability for introduction into industrial production or further breeding practice and prove that green bean varieties are suitable for both vegetable production and high-quality seeds, as well as for biologisation of production through the use of biologically fixed nitrogen