| A field examination was conducted to study the regulatory effects under different nutrient losses on the photosynthetic characteristics and yield of Jun jujube in Akesu area. The results show that nitrogen deficiency had played a significant role in affecting leaf SPAD value, net photosynthetic rate, stomatal conductance, water effect, maximum conversion efficiency of light energy utilization rate and yield, reaching a significant level at 0.05. Also, it was found that potassium deficiency had the minimal impact. In addition, compared with no fertilization treatments, under no shortage of fertilizer treatments (NPK), leaf SPAD value of red dates, cell carbon dioxide concentrations (Ci), net photosynthetic rate (Pn), stomatal conductance (Gs), water use efficiency (WUE), the maximum conversion efficiency of light energy (Fv/Fm) and yield had increased dramatically, resulting in increases in each index at 12.7%, 50%, 100.5%, 48.8%, 5.4% and 53.3%, respectively. However, none of the treatments had no significant influences on jujube leaf transpiration rate (Tr) and the initial fluorescence (F0). Moreover, correlation analysis showed that yield had significantly positive correlations with leaf SPAD values, net photosynthetic rate, stomatal conductance and water use efficiency (P＜0.01). |