Characteristics Of Absorption, Utilization Of Different Varieties And Fertilization By Apple

The experiment using fifteen-year-old"Fuji"apple trees(Malus domestica Borkh. cv. Red Fuji/ M. hupenensis Rhed) and eight-year-old"Gala"apple trees('Gala'apple Malus domestica/ Malus hupehensis) in the field as main materials was carried out in Yiyuan and Yantai apple orchard of Shandong from 2008 to 2009. It mainly studied the characterrstics of¹⁵N absorption,drstribution and utilization of different varieties of Fuji apple before germination under the condition of field cultivation and that of the"Gala"apple under the different fertilize depths and different frequencies treament by using tracer technique of¹⁵N. The main results are as follows:1. The characteristics of absorption, distribution and utilization of soil applied¹⁵N-urea in spring under the condition of field cultivation by using fifteen-year-old spur-type and common-type'Fuji'apple trees (Malus domestica Borkh. cv. Red Fuji/ M. hupenensis Rhed) were studied. The results showed that the Ndff of fine root was the highest in both spur-type and common-type at full-bloom stage, which were 0.41% and 0.29% respectively ,and the Ndff of spur-type was significantly higher than that of common-type; At new shoot growing and flower bud differentiation stage,¹⁵N absorbed by root was preferential distributed to the new vegetative organs, and the Ndff of all organs in spur-type were higher than that of the common-type except leaf; At fruit rapid-swelling and fruit maturity stage, the Ndff of fruit in spur-type and common-type was the highest, but the Ndff of spur-type was higher than that of common-type; After harvest, the Ndff of thick root was the highest in both spur-type and common-type, which were 0.91% and 0.79%, but the Ndff of spur-type was higher than that of common-type. The distribution ratio of¹⁵N in various organs of spur-type and common-type was different in different phenological periods, at full-bloom stage, the content of 15N was the highest in storage organs, and there was not significantly difference between the two varieties;At new shoot growing and flower bud differentiation stage, the distribution ratio of¹⁵N in storage organs of spur-type and common-type declined,15N was mainly distributed to the vegetative organs, the distribution ratio in spur-type was lower than that in common-type; At fruit rapid-swelling and fruit maturity stage, reproductive organs in spur-type and common-type were changed into growth center, the distribution ratio of spur-type was significantly higher than that of common-type; After harvest, 15N backfluxed and accumulated in storage organ, and the content of spur-type was higher than that of common-type, with the process of growth. The ratio of utilization of¹⁵N-urea increased gradually in spur-type and common-type by Fuji¹⁵N-labelled urea via soil in early spring, and reached the highest after harvest, which were 24.64% and 16.31% respectively; the ratio of utilization of¹⁵N in spur-type was general higher than common-type during the whole growth stage.2. The characteristics of¹⁵N absorption,distribution and utilization of eight-year-old"Gala"apple trees under the treatment of soil applied¹⁵N-urea in different depth were studied.The result showed that the difference of Ndff was significantly in different organs of apple trees with the different fertilizing depth.The Ndff in different organs of apple trees with fertilizing in middle dpeth(20cm) was obviously higher than that of deep fertilization(40cm) and surface fertilization (0cm) .The Ndff of thin root was the highest in these three fertilization type at full-bloom stage, and the second was thick root. At new shoot growing and fruit rapid-swelling stage,¹⁵N absorbed by root was preferentially distributed to the new vegetative organs.,The Ndff of fruit was the highest at fruit maturity stage,and the Ndff of the new organs was generally higher than that of storage organs. After harvest,the Ndff of¹⁵N in the roots was the highest,and was higher than that of in storage organs above ground.The Ndff in the new vegetative organs descended to relatively lower level.¹⁵N ccumulated in apple trees began to backfluxed and accumulate into storage organs.The distribution ratio of¹⁵N was different in various organs at different phenological stages, but there was not significantly difference in different depth.With the process of growth,the ratio of¹⁵N utilization of apple trees under different treatment of soil fertilize¹⁵N-urea increased gradually and reached to the highest after harvest, which were 20.06%,28.15% and 13.39% respectively,and the value when fertilizing in middle was general higher than that in deep and on surface.3. The characteristics of absorption,distribution and utilization of eight-year-old"Gala"apple trees under the treatment of different fertilization times was studied. The results showed that the Ndff in different organs of apple trees wae obviously different with different ways of fertilization at the fruit maturity stage,and the Ndff of the organs is generally higher when using split application than that of disposable fertilization.The Ndff of fruit was the highest under both treatments, and the value was 3.22% and 2.81% respectively,followed by long shoot leaves, short shoots and long shoots.The Ndff of fruits and roots,which are treated by split application at the new shoot growing stage and the fruit rapid-swelling stage is lower than that of the disposable fertilization, but the Ndff exceeded it during the fruit maturity stage.At the fruit maturity stage,the distribution ratio of Ndff in reproductive organs is the highest,and the value treatmented with split application was relatively higher than that of disposable fertilization, reached to 60.22% and 57.35%,respectively,but the ratio of¹⁵N in vegetative and storage organs treatmented with disposable fertilization was higher than Split application Spit application can significantly increase the ratio of¹⁵N utilization, and the value increased by 27.52% compared with that of disposable fertilization.