Variability of Seasonal Conditions and Hybrid Influence on Sunflower (Helianthus annus L.) Productivity and Oil Content

This study examines the influence of seasonal conditions and hybrid selection on the yield-forming parameters, seed yield, and oil content of sunflower (Helianthus annuus L.). The research was carried out as a field experiment on the plots of AGRO SAP s.r.o., located in the village of Nenince, Slovakia. Four sunflower hybrids (ES Poetic, ES Electric, SY Talento, Marbelia CS) were selected to monitor the variability of the selected parameters during the growing seasons 2020-2022. The statistical analysis of the collected data confirmed a highly significant effect of the studied factors on productive traits of sunflower. Over the study period, the average yield of sunflower was 3.48 tonnes per hectare (t/ha), with an average oil content of 38.92%. Among the climatic factors analyzed, precipitation distribution had the greatest influence on oil content, while temperature fluctuations were the key factor affecting seed yield. The seasonal conditions of 2020 was the most favorable for yield-forming parameters, recording the highest head diameter (176.6 ± 0.82 mm), head weight (182.83 ± 8.46 g), and thousand seed weight (TSW) (64.58 ± 2.23 g). However, 2021 provided optimal conditions for seed yield (3.79 ± 0.24 t/ha) and oil content (40.51 ± 0.51%). Among the hybrids, Marbelia CS excelled in yield-forming traits by head diameter (168.5 ± 1.51 mm), TSW (64.33 ± 2.34 g), while ES Poetic showed the highest seed yield (3.69 ± 0.36 t/ha) and ES Electric recorded the highest oil content (39.43 ± 1.15%). These findings highlight the importance of seasonal climatic conditions and hybrid selection in sunflower cultivation, providing essential insights for optimizing yield and oil production.