Abstract: Using 15 sweet potato [Dioscorea esculenta (Lour.) Burkill] varieties as experimental materials, the main agronomic and photosynthetic traits of 15 sweet potato varieties were studied. The grey correlation method and DTOPSIS method were used to comprehensively evaluate these agronomic and photosynthetic traits of sweet potatoes. The results showed that there were differences in these traits of sweet potatoes, with a coefficient of variation ranging from 20.15% to 76.98%. The correlation analysis showed that the leaf area of sweet potatoes was significantly positively correlated with stem diameter(P<0.05), negatively correlated with the number of branches per plant(P<0.05), and highly significantly positively correlated with the longest vine length(P<0.01); there was a significant negative correlation between chlorophyll SPAD and commodity yield(P<0.05); there was a highly significant positive correlation between stem diameter and the longest vine length(P<0.01), as well as a significant positive correlation with the number of tubers per plant(P<0.05); the longest vine length was significantly positively correlated with the number of tubers per plant(P<0.05). The order of influence of agronomic and photosynthetic traits on sweet potato yield was as follows from high to low： number of branches per plant, stem diameter, dry matter rate, commodity rate, the longest vine length, net photosynthetic rate, chlorophyll SPAD value, leaf area and number of tubers per plant. The DTOPSIS method was used to comprehensively evaluate the main agronomic and photosynthetic traits of sweet potatoes. The top eight varieties in the comprehensive ranking were the same as the top eight varieties in sweet potato yield, and the order of the top two varieties was switched. The DOTPSIS method could be used as a comprehensive evaluation method for sweet potatoes, and Hami, Pushu 32, Shangshu 19, and Jishu 33 were selected as suitable for demonstration and promotion in Zhengzhou City.

Key words: sweet potato [Dioscorea esculenta (Lour.) Burkill], agronomic trait, photosynthetic trait, grey correlation analysis, DTOPSIS method