Studies On Charactritics Of The Absorption, Distribution And Utilization Of Foliar Application Of ～(15)N-Urea In 'Hongdeng' Sweet Cherry

The experiment using the stable isotope 15N-labelled urea was carried out in orchard in Yuanzhuang ,Shandong Taian from 2004 to 2005. The characteristics of absorption, distribution and utilization after 15N-urea daubing on the leaf of different branches in different fertilizer stages and the effect of foliar spray of urea on the horticultural characters under the condition of field cultivation by using seven-year-old'Hongdeng'sweet cherry (Prunus.avium L. var. Hongdeng/Daqingye) were studied. The main results were as follows:1. 15N-urea daubed on the leaf after full blossom, 15N traslocation in'Hongdeng'sweet cherry was in accordance with the rule of N nutrition distribution in deciduous fruit trees, and 15N was transported with the growth centre transporting. The 15N-urea absorbed by the leaf of different branches in different stage have the different characteristics of traslocation. When analyzed at fruit core-hardening phases, the 15N absorbed was distributed preferentially into the fruit.The leaf of branches have the stronger ability of transporting 15N than the leaf of spur. And analyzed at fruit mature stage, 15N absorbed by the leaf of branches was transported and used to the construction of new organs; but 15N absorbed by the leaf of spur was distributed preferentially into the fruit. And analyzed at balloon phase the next year, Ndff% in the leaf of branches was highest (0.362%) in the treatment of 15N daubing on the leaf of branch. Ndff% in fruit was highest (0.405%) in the treatment of 15N daubing on the leaf of spur. This improved that 15N absorbed by the leaf during growth season has the characteristic of store and recycling. The 15N absorbed by the leaf of long branches and spur was transported by the different direction: The was transported medially in the next year balloon phase, but 15N absorbed by the leaf of long shoot leaf display the characteristic the polar assignment.2. The leaf of branch and spur had a higher ability of absorbing 15N after applying high concentration of 15N-urea to leaf of sweet cherry trees, NDFF% reached 8.115%, 12.932% respectively, 15N utilization rate was about 80%, and 15N absorbed can be transported to each part of tree body, thus foliar...