Effects of Different Nitrogen and Phosphorus Application Ratios on Leaf Growth and Physiological Characteristics of Passiflora edulis Sims

By studying the effects of different nitrogen and phosphorus application ratios on the growth and physiological characteristics of Passiflora edulis Sims leaves, it can provide a reference for the scientific fertilization during the vegetative growth period of Passiflora edulis Sims. The pot experiment was carried out, and no fertilization (T1) was set as the control. The ratios of nitrogen to phosphorus were set as 5 treatments, and T2-T6 were 1∶1 (T2), 1.5∶1 (T3), 2∶1 (T4), 1∶1.5 (T5), 1∶2 (T6), respectively. Then, the changes of fresh weight and physiological indexes of Passiflora edulis Sims leaves were analyzed. The results showed that: the fresh weight of leaves was significantly increased under T4 treatment at 100 days after fertilization treatment compared with T1, T2, T3 and T5; the content of superoxide anion in leaves under T4 treatment was significantly lower than that in T1, T3 and T5 treatments on the 25th, 75th and 100th day; the APX activity in leaves under T4 treatment was significantly higher than that in the other five treatments; the MDA content of leaves under T4 treatment was significantly lower than that in T1 and T2 treatments, and the soluble sugar content of leaves was significantly higher than that of the control and other treatments; the proline content of leaves under T4 treatment was significantly higher than that in T1, T2, T5 and T6 treatments on the 75th and 100th day after the treatment. According to the comprehensive analysis, the application ratio (2 ∶ 1) of nitrogen and phosphorus in the vegetative growth period of Passiflora edulis Sims was the appropriate fertilization ratio to promote the growth of Passiflora edulis Sims leaves and improve the physiological characteristics.