Studies On Potassium Absorption And Accumulation Chararcteristics And Potassium Effciency Of Varieties Of Sweet Potato

Sweet potato prefers potassium (K) and K deficiency leads to decrease in production, quality decline, infectious virus and a series of problems. It’s a very important to improve K use efficiency by the efficient management of K by using and breeding K high-efficiency varieties of sweet potato. The present studies have shown that the capacity of uptake and use of K of different sweet potato varieties is very distinctive. So the use and breeding of K-efficient sweet potato, and the tapping of sweet potato’s genetic potential are efficient measures to increase the efficiency of K fertilizer and to reduce the effects of K deficiency to sweet potato development and production. In this study, a field experiment and an indoor pot experiment were conducted to study the K accumulative characteristics and the K use efficiency of different varieties of sweet potato. Main results were as follows:The pot experiment has shown that biomass of sweet potato and the K accumulation value were increased gradually up to the reproductive period along with the advancement of growth process and reached maximum at booming phase and then decreased at the harvest stage due to the reduction in aboveground biomass and K accumulation. At the same time, K fertilization obviously increased the accumulation of underground part’s biomass. The results of K contents of different underground parts of sweat potato showed that two varieties N88 and J22 showed that petiole has the highest concentration of K followed by leaf, while stem showed the lowest K concentration. Later with the growth of sweet potato, leaf showed the most accumulation of K, followed by petiole and stem. The K accumulation was not high at the tips of leaf and stalk, but it was high in the upper part followed by middle part and declined. The stem showed different results and the K was reached maximum at the top, and then gradually decreased. The result also showed that with the application of K fertilizer, the accumulation of K from plant’s top to bottom varies in a smaller range compared with control where K fertilizer was not applied.Total 17 sweet potato varieties were tested for underground biomass and K uptake efficiency and three K high-uptake-efficiency varieties, SU17, SU11 and JIhei1 and three K low-uptake-efficiency varieties, Ji22 Xu083228, Q37-2 and R43-5 were selected. While three sweet potato varieties Ning6-10, Q37-2 and Su17 showed K high-utilization-efficiency and three varieties Xu082909, Wanshu5 and Xu085919 showed K low-utilization-efficiency.The field experiment of the K efficiency of 16 sweet potato varieties has shown that under different K-fertilization conditions, the biomass of different varieties of sweet potato showed differences especially the underground part. There were great differences of K concentration and accumulation in vine and tuberous root of different varieties of sweet potato.After experiments, the varieties showed K high-uptake-efficiency:XU 082909, NAN88 and Q37-2; K low-uptake-efficiency:JIHEI 1, Ningzi1 and XU085919; K high-utilization-efficiency:Wanshu5, Su17 and Q37-2 and K low-utilization-efficiency:Ji22, Wanshu6 and Xu085919 were selected.The pot experiments results compared with the field results showed that pot experiments just paly a helpful role need to test in field experiments. The field and pot experiments results showed a preliminary selection of K high-efficiency varieties; SU17 and Q37-2 and; Wanshu6 and Xu085919.