Field Spraying of Cytokinin as a Potential Tool to Improve Postharvest Soybean Quality

This study evaluated the effects of cytokinin application at different phenological stages of soybean on postharvest grain quality parameters. Plants were treated during vegetative and reproductive stages, and the harvested grains were analyzed for chemical composition, thousand-grain weight, test weight, colorimetric profile, electrical conductivity, leached solids, phenolic compounds, acidity, and soluble protein. At the early reproductive stage (R1), cytokinin application increased the soluble protein, suggesting positive effects on protein metabolism and stability. Applications at intermediate vegetative stages, such as V3 and V4, promoted higher thousand-grain weight, indicating improved dry matter deposition. Overall, cytokinin modulated grain composition and quality traits depending on the phenological stage, highlighting the importance of the timing of the application.