Fatemeh Samadzadeh

Sesame (Sesamum indicum L.) is a globally significant oilseed crop valued for its high-quality oil, rich in unsaturated fatty acids and antioxidants, yet its production faces challenges such as low yield, shattering losses, and variable oil quality, particularly in semi-arid regions like Iran where domestic demand necessitates enhanced local cultivation. This study aimed to investigate how row spacing (30, 45, 60 cm) and plant density (5, 8, 11, 14 cm) affect oil yield and fatty acid composition in the non-shattering sesame cultivar. Conducted in 2020 at the Moghan Agricultural Research Station in Northwest Iran, the experiment utilized a strip plot design based on a completely randomized block design with four replications. Treatments combined row spacings and plant densities, with oil content and fatty acid profiles analyzed via gas chromatography, and data evaluated using ANOVA, LSD and regression tests. Results revealed that a row spacing of 45 cm with plant spacings of 8–11 cm (20–28 plants/m²) maximized oil content at 55.45% and optimized fatty acid profiles, particularly increasing linoleic acid (up to 48.31%) while maintaining oleic acid levels (up to 40.85%), with significant RS × PS interactions (P < 0.01) highlighting their combined influence. These findings provide practical recommendations for Iranian farmers to enhance sesame oil quality and yield, contributing to sustainable production systems in semi-arid regions and reducing reliance on imported edible oils, while suggesting further multi-year studies to address environmental variability in fatty acid biosynthesis.