Agronomic Performance and Yield Components of Second-Crop Sunflower (Helianthus annuus L.) Genotypes Under the Ecological Conditions of Mardin

Abstract

Sunflower is the primary oilseed crop of strategic importance for reducing Turkey's vegetable oil deficit. Because genotype yield performance as a second crop under the hot, semi-arid conditions of Southeastern Anatolia depends largely on the environment, identifying location-adapted genotypes is critical. This study evaluated the agronomic performance of 20 oilseed sunflower hybrids grown as a second crop after irrigated wheat at two Mardin locations (Artuklu and Kızıltepe) in 2022. Trials used a randomized complete block design with three replications per location. Genotype means ranged from 2,653 to 3,948 kg ha⁻¹ for grain yield, 37.7–42.3% for oil content, and 1,064 to 1,649 kg ha⁻¹ for oil yield. In the combined analysis of variance, the genotype × location interaction was significant for these three traits, with genotype rankings differing between locations. DERAY ranked in the highest yield group at Artuklu but the lowest at Kızıltepe, whereas SUN 2239 CL ranked highest at both. The interaction was non-significant for physiological maturity, head diameter, thousand-kernel weight, hectoliter weight, and hull percentage. These results indicate a need for location-specific rather than region-wide variety recommendations. SUN 2239 CL, DATAEM, and LG 5485 performed well at both locations.