Effect of copper stress on photosynthesis of navel orange seedlings The Effects of Drip Fertigation on Tree Growth and Fruiting of Trovita Sweet Orange(Citrus sinensis Osbeck)in Calcareous Purple Soil in Chongqing of China Relationship between Boron Deficiency Occurrence and Annual Changes inContents of Boron and Sugar of Newhall Navel Orange Relationship between Boron Deficiency Occurrence and Annual Changes inContents of Boron and Sugar of Newhall Navel Orange Relationship Between Boron Deficiency Occurrence and Changes in Contents of Different Boron Forms in Leaves of Newhall Navel Orange During Fruit Development Relationship Between Boron Deficiency Occurrence and Changes in Contents of Different Boron Forms in Leaves of Newhall Navel Orange During Fruit Development Studies on 45S rDNA-FISH of Natural Polyploids in Citrus sinensis Osbeck.‘Hongjiangcheng’ Effects of Two Kinds of Rootstocks on the Growth of Navel Orange (Citrus sinensis Osbeck)Young Tree and the Annual Changes in the Contents of Carbohydrates in Leaves