Seed yield and quality of confectionary sunflower varieties depending on plant populations

We studied reaction of six sunflower confectionary varieties SPK, Lakomla, Oreshek, Krupnyak, Dzhinn, Belochka on plat population equal 20, 30, 40, 50 thousand plants per ha on leached black soils of the Krasodar region in 2015-2017. We stated the maximal yield of a seed fraction 38+ was obtained at plant population 30 thousand plants per ha: 2.79-2.80 t per ha for Oreshek and Lakomka, 2.84 t per ha for Krupnyak, 3.03-3.08 t per ha for SPK, Belochka, Dzhinn. Increase of plant population from 20 to 50 thousand plants per ha leads to decreasing of head diameter from 24.8 to 18.0 cm, amount of formed seeds per head - from 1264-1418 to 822-926 seeds, output of the main seed fraction 38+ - from 91-94 to 69-74%, 1000 seeds weight - from 121-130 to 93-97 g, output of seed fraction 38+ with achene length 12 mm - from 69-72 to 32-39%. Increasing of plant population also leads to increase of seed volume weight from 342-346 to 354-360 g per liter.