Influence of weather conditions on the expression of economically valuable characteristics of alfalfa variety Vega 87

A comparative evaluation was conducted of the original samples of Medicago varia of the Vega 87 variety, whose seeds were grown in seed preservation nurseries, in years differing in moisture and temperature availability. The growing season in 2010 was hot and arid, hydrothermic coefficient (GTK) is equal to 0.49; 2011 was not humid enough, GTK 0.92. Weather conditions in 2007, 2012, 2016 and 2017 were close to the annual average, GTK 1.09–1.50. It was found that the average productivity of the herbage grown from these seeds, on average over three years of use (2023–2025), was 1.63± 0.15 kg/m2, the specific values of individual samples ranged from 1.57–1.73 kg/m2. In the "beginning of flowering" phase, the average foliage of alfalfa plants was 47.1±1.0% with fluctuations in individual samples from 46.3 to 49.4%. During this phase of development, the average crude protein content was 19.29±0.63%, and for individual samples it was 18.56–20.73%. In the "beginning of budding" phase, foliage was in the range of 48.8–51.3%, with an average value of 50.0±0.8 %. At this time, the crude protein content reached 23.27–24.54%, with an average value of 23.76±0.47%. The differences between the particular values of foliage, crude protein content and the average values of these indicators were not significant. Alfalfa of the Vega 87 variety, having a relatively low foliage in the "beginning of budding" phase, increased the crude protein content to 23.20–24.54% in conditions of increased heat supply. Consequently, the variable alfalfa Vega 87 variety is a valuable source material for creating new varieties with stable preservation of varietal qualities during seed propagation in different weather conditions.