Study on biomass and nutrient accumulation of Zizyphus jujube tree under dwarfing and high density culture Effects of fertilization on growth and seasonal dynamic of leaf nutrients of close planting pear-jujube trees STORAGE AND RECYCLING UTILIZATION OF LEAF-NITROGEN OF JUJUBE TREE SELECTION OF RESISTANT VARIETIES AND INDIVIDUALS OF JUJUBE TREES TO JUJUBE WITCHES-BROOM DISEASE Spatial pattern of root systems of dense jujube plantation with jujube age in the semiarid loess hilly region of China Response of upland jujube tree trunk diameter to different ecological factors Studies on insect community characteristics and time dynamics of juju be tree in greenhouse