Influence of agrotechnical practices on yield qualities of seeds in F1 of the sunflower hybrid Surus

The field experiment was conducted in the experimental seed-growing farm “Berezanskoe”, Korenovsk district, Krasnodar region, on sowings of the promising sunflower hybrid Surus on leached chernozem of the Western Ciscaucasia. Plots placement is systematic, in three replications; plot square is 112 m2. The purpose of the research was to study effect of agrotechnical practices (fertilizer, chemical and biological plant protection against diseases) and seed-sowing rates (65 and 75 thousand pcs/ha) on a hybridization plot during cultivation of seeds F1 (2021) on yield and quality of commercial seeds in progeny (2022) of sunflower hybrid Surus planted with seed-sowing rates of 60 and 80 thousand pcs/ha. The agrotechnical practices applied on the hybridization plots did not influenced significantly on yield in progenies; also they did not effect the prevalence of downy mildew, rust, and bacterioses on sunflower plants. There was insignificant impact on an infection level of the sunflower plant with fusarium root rot, alternaria, and phoma rot that influence a little the crop yield. The highest yield in F1 - 3.21 t/ha - was stated in 2022 at seed-sowing rate of 60 thousand pcs/ha, in a variant where were used seeds obtained in 2021 at a seed-sowing rate of 75 thousand pcs/ha on a hybridization plot and fertilizers and chemical ways of plant protection were applied. Therefore, at sufficient water supply in soil, the seed-sowing rate of 60 thousand pcs/ha of F1 hybrid Surus considered to be scientifically proved as it allows obtaining high and stable yield and qualitative sunflower products in progenies. When fertilizers, chemical ways of plant protection and a seed-sowing rate of 75 thousand pcs/ha were applied on a hybridization plot in 2021, the highest net profit and profitability were obtained in 2022 at both seed sowing rates in F1 (60 and 80 thousand pcs/ha) - 35163 and 33933 RUR/ha, 78 and 75%, respectively.