Effects of First or Second Section Vine on Yield and Growing Character in Sweetpotato

The experimental results of first(0～25 cm with apex) or second(25～50 cm) section vine of 3 sweetpotato varieties showed that the first vine could very significantly increase the row starch content of dry slice than second vine,the first vine was beneficial to increase the rate of mini root which is good for fresh eating,the second vine was beneficial to increase the rate of bigger root.Among 3 varieties,① compare with the root number,the yield of dry slice,row starch and fresh root,the first vine of Guangshu-87 could increase 51.7%,38.7%,41.9% and 20.2% respectively than the second vine,and the first three date were significantly difference;②compare with the yield of dry slice,row starch and fresh root,the first vine of Guangshu-79 could increase 15.3%,11.9% and 20.0% respectively than the second vine;③on the contrary,compare with the fresh root weight per plant,the yield of fresh root,dry slice and row starch,the second vine of Pushu-24 could increase 12.0%,12.0%,15.7% and 11.8% respectively than the first vine.Therefore,we have to choose the first or second section vine according to the varieties character even the marketing objection.