Adaptive sunflower cultivation under climate change conditions

Abstract

Sunflower is one of the leading oilseed crops in Ukraine, but its productivity is increasingly constrained by climate change, particularly drought, high temperatures, and uneven rainfall distribution. The aim of the study was to evaluate the role of resource-saving nutrition and hybrid selection in stabilizing sunflower productivity under contrasting agroecological conditions of Ukraine. Field studies were conducted in 2025 in the Southern Steppe and Northern Forest-Steppe zones. In the Southern Steppe, the response of Bastion and Forsazh hybrids to seed treatment with Mykofrend, moderate N30P15K15 mineral fertilization, and foliar applications of Organic Balance, Azotohelp, and boron was studied. In the Northern Forest-Steppe, eight sunflower hybrids were evaluated for seed yield, oil content, oil yield, thousand seed weight, and seed bulk density under drought and heat stress. The results showed that, despite severe moisture deficit in 2025, resource-saving nutrition improved sunflower yield formation. The highest yield in the Southern Steppe was obtained when seed treatment, N30P15K15, Organic Balance, Azotohelp, and boron were combined: 1.26 t/ha for Bastion and 1.30 t/ha for Forsazh. Forsazh showed a slightly better response to the studied nutrition system. In the Northern Forest-Steppe, the highest productivity was recorded for LG50635, with a seed yield of 1.70 t/ha, oil content of 44.0%, oil yield of 0.75 t/ha, thousand seed weight of 48 g, and seed bulk density of 360 g/L. ES Belfis and P64LE25 also demonstrated high adaptive capacity. The study confirms that combining resource-saving nutrition with adapted hybrid selection can reduce yield losses, improve seed quality, and increase the stability of sunflower production under climate change conditions.