Growth response of Michelia mediocris Dandy planted under different levels of canopy openness and different types of fertilisers

Abstract

Michelia mediocris Dandy. is a native-tree, evergreen broadleaf species. Growth responses of M. mediocris seedlings to different light conditions were tested by planting under different canopy openness levels of mixed Pinus massoniana and Acacia mangium plantation in Chi Lang, Lang Son and under degraded natural forest in Hoanh Bo, Quang Ninh. The effect of different types of fertiliser on seedling growth was also tested in Hoanh Bo, Quang Ninh. Results showed that, diameter and height growth were significantly higher in the treatment of 0.25 - 0.45 canopy openness, which suggested that the species is shade-tolerant in the seedling stage. However, at age 3 years, the demand for light become higher which was shown by better growth rates of both diameter and height in the canopy openness of 0.0 - 0.25. At age 4 years, the saplings grew best in the treatment of 0.0 canopy openess which indecated that the species become light demander at
this age. For fertiliser, seedling growth was significantly higher in the treatment of fertilising with 1kg compost of chicken waste/seedling and 0.2kg Song Gianh micro-organic fertiliser/seedling in comparison with the treatment of 0.1kg NPK (5 : 10 : 3) and the control. Shading is important
for early establishment and growth of M. mediocris seedlings, but adjustment of shading level when tree grow up is needed to facilitate seedling growth. Organic fertilisers are suitable for fertilising M. mediocris seedlings.