Duration of vegetative phases and vegetative period of sunflower hybrids of domestic and foreign breeding depending on agrocenosis density and environments of cultivation zones in Krasnodar region

The results of three-year studying conducted in three soil-climate zones of Krasnodar region: northern, central and southern-submountain are resulted. It is showed the changes in vegetative period of three sunflower hybrids Yupiter (VNIIMK, Russia), Pomar (Euralis Semans, France) and С-207 (Monsanto, USA) depending on agrocenosis density and soil-climate conditions in cultivation zones.