Effect Of Potassium Application Methods On The Accumulation And Distribution Of Photosynthates And The Yield Of Sweet Potato

Regulating the Potassium application methods stage on the accumulation and distribution of photosynthates and the yield of sweet potato by using two different yield potential level of sweet potato varieties are Beijing 553 and Hongxiangjiao in Agronomy Experimental Station of Shandong Agricultural University. The main results were as follows: 1 Potassium application methods stage on fresh yield and yield compentsPotassium fertilizer application could increase the storage root yield of sweet potato, the increase rate is different between the different varieties. Application potassium as basal of two varieties can best improve production potential yield, Application potassium as basal not only improved the single chips but also raised the potato number per. The treaments as T3, T4 reduced the sweet potato plant potato number per plant, the increased production is mainly improved the single chips. Compared with the control treatment, the application potassium of two varieties increase the storage root yield not only improve the biological yield also increased the economic coefficient; between application potassium treatments, increase root yield is mainly due to the improvement of economic coefficient, not the biomass. 2 Potassium application methods stage on accumulation of photosynthatesHongxiangjiao,s photosynthetic rate is higher than Beijing 553; application potassium can an improve the sweet potato photosynthesis and the photosynthetic potential; at the early growth time application potassium as basal can grow significantly stomatal conductance, net assimilation rate. Before stem leaf growth peak, Hongxiangjiao,s biological yield higher than tBeijing 553, at the harvest time Beijing 553,s biological yield is higher than red banana; Compared with Beijing 553, Hongxiangjiao has a larger production potential(K) root fresh weight, root swelled the initial potential(C0), the average accumulation rate of theHongxiangjiao(Vmean), peak time and its root expands rate, so the Hongxiangjiao root formed early and expands quickly. Application potassium of two varieties production potential(K) root fresh weight and root swelled(C0) is significantly higher than the control treatment, application potassium as basal improve the most significant; At the same time(T2) can ahead the time of rate peak came and can prolong root duration. Application potassium as basal promote root rapid enlargement, as soon as possible the base potassium application handle the early potatoes and enlargement, accumulation of high accurate to start, fast to form a certain capacity of metabolic library, laid the foundation for obtaining high yield; Potash fertilizer topdressing late or without potassium, action time is shorter, miss the sweet potato biggest expands applied period. 3 Potassium application methods stage on distribution of photosynthatesThe T/R ratio of Hongxiangjiao is significantly lower than the Beijing 553; at the harvest time the Beijing 553 rate of root dry weight is lower than Hongxiangjiao, while the rate of stems dry weight Of Beijing 553,is higher than Hongxiangjiao.At the top cover fertiler time, the application potassium as basal can significantly reduce the T/R ratio, and at the harvest time can significantly reduce the stem dry weight, so in the early growth the photosynthetic products can transported to the root, promote root expends. During early bulking stage,applying potassium as basal(T2) significantly increased dismater of stem,reduced the starch content of top of stem, increased the sucrose and soluble sugar content, while reducing starch, soluble sugar and sucrose content in the stem base. At the bulking stage, applying potassium as basal(T2) significantly shorten the distance of source to libraries,reduced starch content of stem top and sucrose and starch content of stem base at the late bulking stage. 13 Clabeled by the plants showed that: 13 C of Hongxiang jiao shoots organ allocation rate, at the late bulking the photosynthate allocation of stage leaf and growing points of collateral of Hongxiang jiao is less. Compared with the control treatment, applying potassium as basal(T2) significantly increased allocation ratio of assimilate in the upper roots and reduced allocation ratio of assimilate in upper organ; significantly increased ratio of tuber dry matter before the bulking stage station the harvest accumulation. 4 Potassium application methods stage on nutrition of the plant’s absorobCompared with the control treatment, in the main growing period potassium treatments enhanced potassium content of leaf petiole, decreased nitrogen content of stem, root and decreased N / K ratio of various organs; Application potassium as basal(T2) reduce the most significant. Compared with the control treatment, application potassium treatments of two sweet potato varieties could significantly improve accumulation and absorption and utilization of plant potassium, the application potassium as basal(T2) is highest. Compared to three applying potassium treatments, physiological efficiency of application potassium as basal(T2) of the Beingjing 553 is highest, but application potassium as dressing(T3) of Hongxiangjiao is best; potassium of harvest indexof two varieties are application potassium as basal(T2) highest.