The article presents the results of research on millet seeds the crop formation and the quality, depending on its varietal characteristics. It was experimentally proven that in the conditions of the Right Bank Forest-Steppe of Ukraine, the passage of phenological phases of growth and development of millet depended both on varietal characteristics (groups of varietal maturity) and on the number of effective temperatures. The crop yield and quality depended on the phenological phases of growth and development, particularly the phases of flowering and seed formation and their conditions. On average, over three years, early and late ripening varieties had signifcantly lower seed yield compared to other variety samples. Early-ripening, mid-early and mid-late varieties had signifcantly higher seed yield. The lowest productivity was in the very early sample of Dakota – 88.3 kg/ha. The yield of very late varieties – Nezalezhnist, Kanlow and Lyadivske – made 89.7, 88.3 and 99.4 kg/ha, respectively. The study on factors affecting seed yield established that the influence of the factor "variety" was the largest and amounted to 61.1 %, and the factor of "growing conditions" affected the crop less – 11.9 %. Germination energy and seed germination, as well as its yield, depended on the maturity groups of the variety samples. Very early, early-ripening and medium-ripening varieties had the highest quality indicators, no signifcant difference was found depending on varietal characteristics. The mid-late varieties had signifcantly lower quality indicators, and the lowest quality was the very late Kanlow variety. The study on factors affecting seed quality established that the influence of the "year conditions" factor on germination energy and germination was the greatest and was 37.6–48 %, and the "variety" factor was 33.8 and 30 %, respectively. It was found that the later is the variety is of the maturity group, the higher is the sum of effective temperatures it needs and, accordingly, the longer the onset of the phenological phases of growth and development of the crop, which affects the features of seed formation and ripening and, accordingly, its quality and yield. The mid-late varieties had signifcantly lower quality indicators and the lowest ones were observed in the very late variety. Mid-late, late and very late varieties do not ripen biologically, which affects the seeds quality its germination is very low.

Key words: variety samples, maturity groups, germination energy, germination, phenological phases of growth and development.