Seasonal Rhythms of Floribunda Rose Development in Cultivation Conditions in the Right-Bank Forest-Steppe of Ukraine

Climate change continues to intensify globally and regionally, resulting in noticeable shifts in the phylogenetic and ontogenetic characteristics of plant growth and development. Accordingly, the study aimed to investigate the influence of abiotic factors on the growth and development characteristics of floribunda roses. Seasonal dynamics of floribunda rose development in the conditions of the Right-Bank Forest-Steppe of Ukraine were examined during 2021-2023 using standard methods. The relationship between decorative and morphometric traits was evaluated using the correlation coefficient (r). Statistical processing of the research results was carried out using dispersion and correlation analyses. Over three years (2021–2023), the vegetation period of the studied varieties typically began in the second or third ten-day period of March. For all varieties except ‘Minerva’, vegetation ended with the onset of frost. On average, floribunda roses exhibited a growing season of 245 days, with the longest period recorded for ‘Goldelse’ (250 days) and the shortest for ‘Minerva’ (217 days). The mean flowering duration was 124 days across the study years, with the longest flowering observed in ‘Pomponella’ (145 days) and the shortest in ‘Minerva’ (94 days). In 2022, flowering duration was shortest (120 days), likely due to increased temperatures and reduced precipitation during the active growth phase. In the same year, flowering breaks totaled 25 days. The results confirm the significant influence of climatic conditions, particularly air temperature and precipitation, on the duration and dynamics of floribunda rose flowering. A strong positive correlation was identified between flowering duration and both the average air temperature during the active growing season (r = 0.90) and the number of days exceeding 15°C (r = 0.84). Conversely, precipitation levels showed a strong negative correlation with the total duration of flowering breaks (r = –0.96). Thus, floribunda roses can be regarded as continuously flowering plants with a flowering period of up to 145 days, the intensity and dynamics of which depend on air temperature and precipitation. To increase flowering duration by reducing breaks, it is recommended to carry out additional irrigation and watering during dry periods. Also, given the global trends in climate change, the search for, creation, and study of drought-resistant rose genotypes is promising and may be a prospect for further research.