IR Polysk

Agronomic Management of the High-Oleic Hybrid «IR Polisk»

The «IR Polisk» sunflower hybrid, registered in 2025 by the V.Ya. Yuriev Plant Production Institute, is designed for intensive farming in the Steppe and Forest-Steppe zones of Ukraine. As a mid-early maturing hybrid, it balances yield potential with efficient moisture utilization, requiring precise agronomic management.

Sowing and Stand Density

Sowing should commence when soil temperatures reach +10...+12°C at the seeding depth. To maximize the high-oleic oil content and yield, the recommended plant density at harvest is 50,000–55,000 plants per hectare in the Steppe zone and up to 60,000 plants per hectare in the Forest-Steppe. A standard 70 cm row spacing is recommended to support the plant's structural development.

Nutrient Management and Care

• Soil Requirements: The hybrid thrives in fertile chernozem soils with neutral to slightly alkaline pH. Avoid fields with high water tables or compacted subsoil.
• Fertilization: Apply phosphorus and potassium fertilizers during primary tillage to encourage deep root development. Nitrogen application should be completed by the 4-6 leaf stage to ensure vegetative vigor without promoting excessive height.
• Plant Protection: The hybrid features strong stem pubescence, which serves as a natural defense mechanism. Regular scouting is essential during the flowering stage, particularly given the large, downward-facing head structure.

Harvesting should be executed when seed moisture content drops to 7–9%. As a high-oleic variety, maintaining purity during harvest and storage is paramount to ensure the integrity of the oil's fatty acid profile, which is the primary value of this hybrid.