Experiment on the Planting Depth of Grafting Union of Seedlings of Camellia oleifera Clones

In December 2017, 2-year bare-rooted Camellia oleifera ‘Changlin No 4’ seedlings were planted in C. oleifera stand, cut-over land of Cunninghamia lanceolata, harvested Ipomoea batatas land and C. sinensis plantation in 4 towns of Suichang, Zhejiang province. They were experimented with 4 depth of the grafting union for comparison. In December 2018, investigation was made on survival rate and current shoot growth. The result demonstrated that survival rate of planted seedlings was over than 82%, the highest (95.81%) was planted with depth of grafting union of 5-10 cm. The current shoot growth of planted seedlings had evident positive correlation with depth of 0-10 cm, but negative with that of 11-15 cm, with R2= 0.856. The experiment showed that the optimal planting depth of grafting union was 5-10 cm.