Keywords: 
• nutrient solution concentration /
• hydroponics /
• vegetable sweetpotato /
• vegetable value /
• ornamental value

Abstract: In order to study the effect of nutrient solution concentration on the vegetable value and ornamental value of hydroponic vegetable sweetpotato, the vegetable sweetpotato ‘Haida 7791’ was used for hydroponic culture with Japanese garden formula as the basic nutrient solution formula, and clear water as the control. Seven treatments were designed: control treatment（CK） and treatments T1, T2, T3, T4, T5 and T6, in which ‘Haida 7791’ was treated with 0, 0.25, 0.5, 1, 1.5, 2, and 2.5 times the concentration of the basic nutrient solution,respectively, to study the effects of different nutrient solution concentrations on its vegetable value and ornamental value. The results show that an increase in the concentration of the basic nutrient solution within a certain range significantly promoted plant growth and increased the dry and fresh weight of the aboveground part.The yield increased gradually with the nutrient solution concentration. The yield and total yield of the three harvests showed that the treatments T4-T6 yielded higher. In terms of vegetable quality, CK had the best vitamin C and soluble sugar content, and the lowest nitrate nitrogen content. T4 was the highest in chlorophyll content,and CK was the highest in root activity. In terms of top heart leaf color, treatments with low concentrations of the basic nutrient solution was more conducive to the accumulation of anthocyanin, among which CK was the highest in relative content of anthocyanin. The total content of chlorophyll in top heart leaf was the highest in T4. The leaf color parameters was consistent with the relative content of anthocyanin and chlorophyll content. In summary, in terms of vegetable value, T4 had high biomass and high yield, while CK was the highest in soluble sugar content and vitamin C content, the lowest in nitrate nitrogen content and hence the best in nutritional quality. Combined with the performance of yield and quality, it can be considered to use 1.5 times the concentration of the basic nutrient solution at the early and middle stages of growth, and change to clear water at the late stage of growth（before harvest）. In terms of ornamental value, CK was the highest in anthocyanin content and reddest in top heart leaf vein, and T4 was the highest in chlorophyll content. Consumers can choose freely vegetable sweetpotato plants cultured in CK and T4 according to their preferences for red or green.