Effects of Shading and Fertilization on the Growth and Photosynthetic Physiological Characteristics of Transplanted Heptacodium miconioides Cuttings

In order to investigate the effects of shading and fertilization on the growth and carbohydrate content of Heptacodium miconioides cuttings after field planting, two-year-old rooted cutting were used as the experimental material. A two-factor completely randomized block design was adopted, with 2 light environments and 3 fertilizer treatments applied. The study examined the effects of different treatments on the photosynthetic pigments, photosynthetic characteristics, chlorophyll fluorescence parameters, non-structural carbohydrates and growth of the transplanted cuttings. The results showed that the net photosynthetic rate (P_n), minimum fluorescence under light (F_o'), effective photochemical quantum yield of PSII (F_v'/F_m'), photochemical quenching coefficient (q_P), soluble sugar content, starch content, NSC and ground diameter growth of L₁ treatment were significantly lower than those of L₀ treatment. The P_n of the 2 fertilization treatments groups was higher than that of the N₀ treatment, and the soluble sugar content, starch content, NSC and ground diameter growth of leaves were significantly higher than those of the N₀ treatment. The P_n, NSC and ground diameter growth of N₁₉ treatment were 17.87 % and 13.06 %, 21.93 % and 22.35 %, 25.59 % and 24.48 % higher than those of N₀ treatment in L₀ and L₁ light environments, respectively. In conclusion, under the experimental conditions of this study, 60% shading intensity was unfavorable for the growth of transplanted H. miconioides cuttings. Fertilization partially alleviated the adverse effects of shading, with the N₁₉ treatment exhibiting superior growth-promoting effects. Therefore, ambient shading should preferably be maintained below 60%. For fertilizer application, compound fertilizer with higher potassium content is more suitable.