Grain Yield Stability of Spring Bread Wheat Under Contrasting Moisture Conditions: A Six-Year AMMI Analysis in the Non-Chernozem Zone of Russia

Grain yield stability is a key requirement for spring bread wheat (Triticum aestivum L.) in the Non-Chernozem Zone of Russia, where interannual variation in moisture and heat supply generates substantial genotype × environment interaction (G × E). Six genotypes were evaluated across six growing seasons (2019–2024) at a single site in the Moscow region. Stability analyses (AMMI, WAAS, YSI and HMRP) were applied to grain yield only; phenology, plant height and 1000-kernel weight were characterised by means, coefficients of variation and LSD values. Seasons differed markedly: vegetation-period precipitation ranged from 182.8 to 547.0 mm and the seasonal hydrothermal coefficient from 1.1 to 3.8. Mean yield ranged from 3.21 t ha−1 (Line No. 153) to 3.87 t ha−1 (Zlata), with a grand mean of 3.58 t ha−1. IPCA1 and IPCA2 explained 73.5% and 20.4% of the G × E sum of squares. Zlata had the highest mean yield, within the LSD of Line No. 178, together with the lowest YSI (3), whereas Line No. 178 showed the highest single-year yield (7.03 t ha−1) and the greatest variability (CV = 45.6%). Precipitation during emergence–heading was most closely related to the interaction gradient (r = −0.875). Exploratory marker–IPCA1 associations were partly confounded with germplasm origin and require validation in larger, multi-location datasets.