Abstract:

To investigate the regulatory effects of exogenous acetoin on the growth and edible quality of spinach, a pot experiment was conducted with six treatment groups. These included root irrigation with acetoin solutions at concentrations of 0.05, 0.10, 0.15, 0.20, and 0.25 g/L, foliar spraying with acetoin solution at 0.15 g/L, and a control (CK) involving root irrigation with distilled water. Growth indices and quality parameters of spinach were systematically measured under each treatment. The results indicated that exogenous acetoin application significantly enhanced plant growth and modulated specific quality traits. The root irrigation with 0.15 g/L acetoin notably increased plant height and fresh weight yield (P<0.05), with foliar spraying demonstrating a stronger effect than root irrigation (P<0.05). Root irrigation with 0.05 g/L acetoin significantly promoted root growth (P<0.05). Regarding quality, leaf chlorophyll and vitamin C contents were highest under the 0.15 and 0.25 g/L treatments (P<0.05), whereas oxalic acid and nitrate contents were most effectively reduced by the 0.05 and 0.20 g/L treatments (P<0.05). Comparative analysis of application methods revealed that foliar spraying resulted in significantly lower chlorophyll and vitamin C levels, but higher oxalic acid and nitrate levels compared to root irrigation (P<0.05), suggesting that foliar application may be less favorable for improving edible quality. In conclusion, foliar spraying of 0.15 g/L acetoin represents an effective agronomic strategy for enhancing spinach biomass. For the purpose of improving edible quality, root irrigation is recommended. Furthermore, root irrigation with 0.05 g/L acetoin shows potential for applications aimed at promoting root development, such as in seedling cultivation or stress resistance.

Key words: acetoin, spinach, regulation, concentration effect, supplementation method