Multi‐Environment Assessment Reveals Yield Performance, Stability, and Quality Attributes of Flue‐Cured Tobacco Lines With Potential for Cultivar Development in Southern Vietnam

Flue‐cured tobacco is an important cash crop in Vietnam, but climate variability and disease pressure threaten production. This study evaluated four F 8 breeding lines (2017, 2024, 2030, and 2031) and three check cultivars (Sp225, K326, and K346) for agronomic performance, yield, quality, field disease incidence, and stability. Field trials were conducted during the 2022–2023 and 2023–2024 growing seasons at Gia Lai and Tay Ninh provinces using a randomized complete block design with three replicates. Genotype effects were significant for growth and yield traits but not for quality traits. Lines 2024 and 2031 had the highest mean dry yields (3.55 and 3.49 t ha −1 , respectively). Stability analysis showed that line 2017 had the lowest average sum of ranks (ASR = 2.0) for dry‐yield stability. Line 2031 provided the balance between yield and stability (ASR = 2.2), while line 2024 had the highest yield with intermediate stability (ASR = 3.9). AMMI partitioning attributed 42.7% of dry‐yield variation to genotype, 37.1% to environment, and 20.2% to genotype × environment interaction (GEI), with the first two principal components explaining 90.4% of G × E. In the GGE biplot, PC1 and PC2 explained 90.7% of G + GE variation. Tay Ninh 2022–2023 was the most discriminating, while Gia Lai 2022–2023 the most representative environment for dry yield. Line 2031 was closest to the ideal genotype, followed by line 2024. Both lines showed low field disease incidences. The results support lines 2031 and 2024 for continued multi‐environment testing and potential release in southern Vietnam.