Evaluation of Sesame (Sesamum indicum L.) Genotypes for Agronomic Performance and Seed Quality Under Subtropical Australian Conditions

Sesame (Sesamum indicum L.) is an important oilseed crop valued for its oil, favourable fatty acid profile, and health-promoting phytoconstituents. However, information on the agronomic performance and seed-quality characteristics of sesame genotypes under Australian growing conditions remains limited. This study evaluated sesame genotypes under Australian conditions using complementary field evaluations at Kingaroy and Emerald, Queensland. At Kingaroy three genotypes (BLACK 2, WHITE 5, and WHITE 3) were evaluated across two growing seasons (2023/2024 and 2024/2025) to provide exploratory observations on oil yield and seed-quality characteristics. Because these genotypes were grown as single field strips and harvested seed was bulked within genotype, the Kingaroy data were treated as descriptive observations rather than statistically replicated genotype or seasonal effects. At Emerald, five genotypes (WHITE 6, BLACK 5, BLACK 2, WHITE 5, and WHITE 3) were evaluated using a randomised complete block design with four biological replicates, allowing statistical assessment of genotype effects on agronomic and seed-quality traits. Genotype significantly influenced crop establishment, first-pod height, screw-pressed oil yield, phytochemical composition, and fatty acid profile, whereas most other growth and yield traits did not differ significantly among genotypes. In the replicated Emerald experiment, final plant density ranged from 17.5 to 43.8 plants/m2, screw-pressed oil yield from 35.7 to 39.7%, total phenolic content (TPC), FRAP, and CUPRAC from 64.8 to 111.6 mg GAE/100 g DW, 87.3 to 124.8 mg TE/100 g DW, and 587.1 to 806.3 mg TE/100 g DW, respectively, and the sesamin and sesamolin from 107.9 to 281.5 mg/100 g DW and 96.6 to 138.9 mg/100 g DW, respectively. WHITE 3 generally showed high values for several phytochemical characteristics, including TPC, antioxidant capacity, and sesamin concentration. The Kingaroy evaluation showed numerical variation in oil yield and seed-quality characteristics across genotype–season combinations, providing complementary exploratory information but not statistical evidence of genotype or seasonal effects. Overall, the replicated Emerald experiment demonstrated substantial genotypic variation in several agronomic and seed-quality characteristics, highlighting the potential for genotype selection to improve sesame production and seed quality under Australian conditions. Further replicated multi-season and multi-location studies are required to assess the stability of these traits across Australian production environments.