Effects of Soil Improvement and Shading on the Growth of Bletilla striata Tissue Culture Seedlings under Phoebe zhennan Forest

In order to explore the suitable growth model of Bletilla striata tissue culture seedlings under the Phoebe forest in hilly areas of central Sichuan, the survival and growth of Bletilla striata tissue culture seedlings under the forest were studied using pine needle earth and shading methods. The results showed that: (1) The survival rate of Bletilla striata tissue culture seedlings was significantly improved after half a year of soil improvement with pine needle earth. After one year of soil improvement, the main growth traits of Bletilla striata were all higher than those of the original soil, and the best way was adding 60 kg/m² pine needle earth. (2) From the end of June to the beginning of October, shading treatment was beneficial for the normal growth of Bletilla striata in forest gaps, among which the shade net with 1.5 m horizontal hanging height and 60% shading rate was the best, and the seedling height, average leaf number and average pseudobulb diameter were significantly higher than those of arched shed shading and control.