Influence of agricultural practices on the sowing properties of seeds of different fractions of the sunflower maternal line

This work was focused on the study of the effect of calibration on the sowing properties of seeds of the maternal form of sunflower VK1-klp A, obtained in different variants of the field experiment on the breeding plot. The study was carried out in 2023 at the farm "Urupskoye" in the Novokubansky district of the Krasnodar region on the ordinary chernozem of the Western Ciscaucasia. The best indicators of seed quality were in variants with the use of fertilizers, as well as the complex application of fertilizers and chemical plant protection against diseases. The total amount of full seeds of the medium and large fractions at seeding rates of 65 and 75 thousand pcs/ha was 84.9 and 80.3 %, respectively. The thousand-seed weight in the experimental variants was 68.5–70.5 g in the large fraction, 56.5–58.7 g in the medium fraction and 42.9–43.8 g in the small fraction. The variation of the indicator values was minimal: in the large fraction – 2.0 g, medium – 2.2 g and small – 0.9 g. The values of the volume weight between the seed fractions varied between 397–409 g/l in the large fraction, 400–413 g/l in the medium fraction and 399–410 g/l in the small fraction. The uniformity of the index within each fraction was also positive. Seed germination and disease infestation were studied in 2024. The seeds obtained were characterized by a high laboratory germination of 92-100% and a low degree of infection with pathogens of fungal and bacterial etiology. In the large fraction of seeds, the highest number of non-germinating seeds was observed – 5.5 %, including those destroyed by dry rot – 4.0 % and bacterial blight – 0.7 %. Seeds damaged by dry rot (1.1 % and 0.4 %) and bacterial blight (0.4 %) were less common in the medium and small fractions.