Abstract:

To improve the introduction and cultivation of Rhododendron lapponicum, varieties that suitable for planting in Chengdu plain were selected. Growth index of the whole plant (crown width, plant height, ground diameter, tillering ability), branches (number of branches, longest branch length, single branch thickness, the number of leaf at the longest branch), leaf (leaf length, leaf width, leaf thickness), summer branches length and heat damage index were evaluated of 11 species of R. lapponicum introduced in this study. The results showed that the 11 varieties of R. lapponicum introduced could adapt to the summer growth in Chengdu plain to a certain extent, among which ‘Royal’ was the most suitable, the increasing of its crown width, plant height, ground diameter, the longest branch length, single branch thickness, the leaf length and the leaf width reached 131.43%, 155.07%, 53.79%, 103.65%, 26.66%, 21.51%, and 27.34%, respectively. The heat injury index of ‘Cheer’ was 0, the lowest. In addition, ‘Pink Honey’, ‘Red Overflowing’ also had good performance. Therefore, ‘Royal’, ‘Pink Honey’, ‘Red Overflowing’, and ‘Cheer’ are able to adapt to the summer growth at Chengdu plain, and could be further promoted.

Key words: Rhododendron lapponicum, summer growth, growth index, heat injury index, Chengdu plain