Influence of cultivation conditions on growth and water use efficiency of zucchini seedlings

With the rapid advancement of facility agriculture, traditional methods of zucchini seedling cultivation face increasing challenges in meeting modern demands for quality and resource efficiency. To address this, a series of experiments were conducted to optimize cultivation conditions aimed at enhancing seedling quality and water use efficiency (WUE). Using the ‘Technology No.1’ zucchini variety as a model, the study evaluated five substrate formulations, four tray specifications, and five concentrations of an alginate composite agent (ACA) under controlled irrigation based on evapotranspiration data. Key physiological parameters, including plant height, stem diameter, dry matter accumulation, root vitality, and WUE, were measured. The results revealed that a substrate mixture of peat, perlite, and vermiculite (0.7:0.2:0.1) significantly improved plant height (+17.0%), stem diameter (+41.9%), dry matter accumulation (+53.2%), and WUE (+40.6%) compared to the peat-only control. The 50-cell tray configuration provided the most effective balance between root development and spatial efficiency, enhancing root vitality by 8.3%. Among ACA treatments, 150 mg L-1 yielded the highest WUE (44.3%) and biomass production, with significantly better performance than both lower and higher concentrations. These findings suggest that the integration of an optimized substrate, tray design, and ACA concentration (peat- perlite - vermiculite substrate + 50-cell tray + 150 mg L-1 ACA) can synergistically improve zucchini seedling quality and water efficiency. This study offers a valuable theoretical foundation for the advancement of intensive and efficient seedling cultivation technologies in facility-based zucchini production.