Effect of light intensity and nitrogen level on growth and biomass of Rauvolfia vomitoria Effect of Paclobutrazol on Photosynthesis and Chlorophyll Fluorescence Under Different Fertilization Rates in Potatoes Effects of planting density and fertilization on growth characters and artemisinin of Artemisia annua L. FATE OF FERTILIZER NITROGEN IN SOIL PLANT SYSTEM UNDER IRRIGATING CONDITION Ⅰ. EFFECT OF NITROGEN LEVEL Effects of alternate partial root-zone irrigation on physiological characteristics and water use of maize under different water and fertilizer conditions