Evaluation of yield components and grain quality of maize in China: Relationships with grain filling characteristics and meteorological factors

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Optimizing maize production and quality under climate change requires a systematic understanding of how yield components and grain quality respond to meteorological factors across different cropping systems. This study analyzed data from a multi-region, interval-sowing experiment conducted across China’s major maize-producing areas from 2018 to 2020. Yield components, grain quality traits, and their relationships with grain filling characteristics and post-flowering meteorological factors were evaluated for spring and summer maize using Analysis of Variance (ANOVA), Principal Component Analysis (PCA), and regression. To reduce genotypic confounding, spring and summer maize were analyzed separately, without explicitly considering varietal differences within each system, focusing instead on meteorological associations. In this study, spring maize showed higher values than summer maize in most yield-related traits and protein content. However, the two cropping systems exhibited different responses to meteorological factors. For spring maize, location accounted for the largest share of variance in key traits such as hundred-grain weight and stem diameter (η² up to 84.2%), whereas sowing date main effects were smaller under the conditions studied. High relative humidity during the post-flowering period was positively correlated with hundred-grain weight and protein content. Amino acid accumulation in spring maize was primarily temperature-sensitive, with higher quality observed in Northeast China. For summer maize, accumulated temperature was positively correlated with hundred-grain weight, stem diameter, stem weight, ear diameter, and starch content. Protein content was negatively correlated with the average diurnal temperature range, while starch content was negatively correlated with average soil temperature at 5 cm depth, and crude fiber content was positively correlated with precipitation. Unlike spring maize, amino acid accumulation in summer maize was correlated with precipitation. The normal sowing date (T2) had the highest hundred-grain weight, but sowing date adjustments showed limited differences in other traits. Quality traits showed no significant variation with location or sowing date in either system. Grain filling characteristics were correlated with stem, ear, and grain traits that contribute to yield and quality. These findings offer a descriptive basis for understanding yield components and grain quality variation in spring and summer maize in relation to environmental factors, and may serve as a reference for future studies on yield and quality improvement and climate resource utilization.