Growth Performance of Agarwood Resin Producing Gyrinops walla Gaertn under Different Shade Conditions

Performance of Gyrinops walla under different shade levels

Abstract

Gyrinops walla Gaertn is the only agarwood resin producing species naturally growing in Sri Lanka, which thrives well in home gardens and forested areas of the wet zone under different light conditions. Due to the scientific discovery of its ability to produce commercially valuable agarwood resin in this species in 2012, G. walla became popular among many sectors. Since then, growers and investors were searching for necessary information for G. walla plantation establishment and sustainably managing them. Due to lack of such information, the present study aimed at finding the performance of G. walla under different light levels. For this reason, 60 G. walla seedlings were planted in the Rubber Research Institute premises in Agalawatte, Sri Lanka in 2015. After 12 months, six plants were provided with 50% shade, and another six plants were provided with 30% shade. The rest of the plants were kept under full sun. After another 14 months, height and diameter of all plants were measured at monthly intervals. Leaf area and leaf chlorophyll content were measured at three month intervals for six plants in each shade level. Lean nitrogen, phosphorus, potassium, and magnesium contents were analyzed at six month intervals covering both wet and dry periods for six replicates under each shade level. According to the results, height and leaf area of G. walla grown under full sun was significantly lower than those under 50% and 30% shade levels. Stem diameter and leaf chlorophyll contents of G. wall grown under different shade levels were not significant. Further, leaf nitrogen, phosphorus, potassium, and magnesium contents did not significantly vary between wet and dry seasons or between shade levels. The survival rate of the plants after 54 weeks after planting as 88%. The results suggest that, G. walla plantations can be successfully established in the low country wet zone of Sri Lanka, and plants grown initially under shade perform better than those grown under full sun.