Improvement of the seed qualities of the sunflower hybrid sums as a result of applying a set of agronomic practices at the hybridization plot

When organizing seed production of new sunflower hybrids, there is a need to develop agronomic practices aimed at increasing the volume of production and quality of seeds. The work is focused on the study of opportunities to improve the sowing and yield qualities of the seeds of an interline sunflower hybrid Sums and the development of a set of agronomic practices implementing this improvement for their use at hybridization plots. The research was carried out in two stages. The first one was conducted in 2021 at the hybridization plot. We studied the effect of different agronomic practices (seeding rate, the use of fertilizers, crop protection chemicals and biological preparations against diseases and pests) on improving the sowing and yield properties of the seeds formed on the plants of the female parent of sunflower hybrid (CMS VK1-sur A). We found that the sowing of seeds of the parental forms of Surus at the hybridization plot with the complex of fertilizers (N23P60K60 at sowing and foliar application of microfertilizers Biostim maslichny (1.0 l/ha) + Ultramag bor (0.5 l/ha) at the stage of 6-8 true leaves and budding) has the highest positive effect on the mass of seeds in the head. The second stage was carried out in 2022 to determine the effect of agrotechnical backgrounds used at the hybridization plot on the biological properties of seeds (laboratory and field germination of seeds) formed in 2021. We established that the biological properties of the seeds formed at the hybridization plot of the hybrid Surus differed to some extent between individual indicators, and by variants of experiment. We noted high field germination (2-13 % higher than in other variants of the experiment) under application of biological plant protection against pests and diseases with microbiological fertilizers at the hybridization plot. The increase in field germination allowed reducing losses in the formation of scientifically justified plant density of the hybrid Surus.