EFFECTS OF TOP DRESSING FERTILIZING AND LIGHT REGIME TO GROWTH OF CINAMOMUM OBTUSIFOLIUM IN NURSERY

Abstract

Cinnamomum obtusifolium A. Chev is a native tree species, evergreen broadleaf with high economic,
social and environmental values. Recently, it becomes one of the main tree species for forest planting in
many locations in Vietnam. However, it has not been planted on large forest areas as inadequate of
scientific basis on physiological, ecological characteristics as well as nursery and planting techniques.
Therefore, it is essential to study on fundamental physiological and ecological characteristics of the
seedling in nursery period, especially demand for fertilizers and light regime. Research results showed
that top dressing by fertilizer NPK (5:10:3) dissolved in water at concentration of 5% exposed higher
survival rate, tree base diameter and height growth than top dressing by watering dilute dissolved
manure or non top dressing. In the first 2 months after sowing, shading 50% showed the highest survival
rate and growth. However, from the 3
rd
month to the 6
th
month, shading 25% is the most suitable light
regime for survival rate and growth. After 6
th
months, it is necessary to remove shade net and expose the
seedlings to natural sunlight before transplanting out.