Effects of Potassium and Manganese Fertilizers on Photosynthesis,Antioxidant Enzyme Activities and Quality of Ningqi 10

Through a single factor pot experiment, the 4-year-old seedlings of Ningqi 10 were used as the experimental materials, and a total of 10 treatments were set up, including without fertilization（CK）, T₁（480 mg/L K）, T₂（960 mg/L K）, T₃（1920 mg/L K）, T₄（25 mg/L Mn）, T₅（50 mg/L Mn）, T₆（100 mg/L Mn）, T₇（480 mg/L K+25 mg/L Mn）, T₈（960 mg/L K+50 mg/L Mn）, and T₉（1920 mg/L K+100 mg/L Mn）. The effects of different potassium, manganese and potassium-manganese combinations on leaf photosynthesis, antioxidant enzyme activity and fruit quality of the main wolfberry variety Ningqi 10 in Ningxia Hui Autonomous Region were studied. The results showed that compared with CK, the application of potassium fertilizer and manganese fertilizer had a significant effect on the photosynthesis of Lycium barbarum, and the SPAD value, G_s, P_n, T_r and WUE of Lycium barbarum were significantly improved. T₈ treatment had the most significant effect on the photosynthesis of Lycium barbarum. At different growth stages, with the increase of potassium, manganese and potassium-manganese combined concentrations, Pro, SOD and POD in Lycium barbarum leaves showed a trend of first increasing and then decreasing, and the enzyme activity of T₈ treatment was significantly higher than that of other treatments, while MDA was the opposite. The combined application of potassium fertilizer and manganese fertilizer can significantly improve the quality of wolfberry fruits. Under the T₈ treatment, the longitudinal diameter, Vc content, soluble sugar and soluble solids of wolfberry fruits are the best among all treatments.