| Satsuma is one of the citrus varieties the most widely cultivated in the world. Rough fruit has many problems, such as thick and rough peel, low TSS, less flavor, which lead to difficulty sale and lower price. This has become an outstanding problem in satsuma industry. The investigation has showed that rough fruit mainly produced in the tree or the branch which has less fruit. The alternate year bearing technology is to divide the Satsuma mandarin into bearing year and non-bearing year. Through high yield, in bearing year fruit tree can reduce rough fruit incidence and achieve good quality fruit. However, if non-bearing could restore vigor and achieve high yield next year remains to be proved.In this study, the materials were Citrus unshiu Marc.cv.Kamei NO.25which planted by interlacing alternate bearing technology in YiChang citrus producing areas and conventional bearing tree that remained stable yield is control. The nutrients were compared between bearing tree and non-bearing tree, in order to provide the basis for alternate bearing extension. The main results were as follows:1. Nutrient content at flower bud differentiation stageSatsuma implemented alternate year bearing in2012, K was the highest content of the non-bearing tree that was2.46%, N was the highest content of bearing tree that was2.58%, and content of P, K in non-bearing tree was significantly higher than bearing tree, the content of N was opposite; the content of Ca, Mg was2.34%,0.35%in non-bearing tree and2.79%,0.45%in bearing tree, nonbearing tree was significantly lower than bearing tree. On the other hand, the starch and the soluble sugar content of non-bearing tree are also significant higher than bearing tree.2. The annual change of mineral nutrient content in the leafFrom April to next January, N, P, K, Fe, Zn content of the leaf on spring shoot showed the trend of decline, Ca, Mg, Mn content was on the rise. The change of Nã€P content was great in April to July, the change of Mgã€K is great in the year. In April N, P, K content of non-bearing tree was lower than bearing tree, however, with the develop of the fruit tree, the content of non-bearing tree was gradually higher than bearing tree. The difference was significant from July to the next January. In the period, Ca, Mg content of bearing tree is highest, the difference between bearing tree and non-bearing tree is significant from May to next January, the difference of Mg content was significant from July to next January.3. The annual change of carbohydrate contentThe soluble sugar content was on the rise. In April the content of non-bearing tree was significant lower than the bearing tree, however, its content gradually exceeded the bearing tree with the growth and development of the fruit tree. In May, July and October the difference reached significance level. Before fruit mature the starch content of non-bearing tree was lower than bearing. After September the tendency was opposite. Even the difference between non-bearing tree and bearing tree is significant in October and January. |
