Abstract:
Agarwood is a highly valuable resin mainly used as incense and perfume manufacturing and
therefore a considerable foreign income can be obtained by the exports. Rubber, one of the main
foreign income generating crops in Sri Lanka faces a severe threat due to low demand at the
international market. Therefore growers are seeking for suitable short rotation species to
intercrop with rubber. Along with that, the present study investigates the potential of
intercropping three agarwood producing species; Aquilaria crassna, A. subintegra and Gyrinops
walla of family Thymalaeaceae with RRIC 121 rubber clone under full sun, 50% and 30%
shades. Those settings were made in two different planting systems, viz., double row (three
agarwood lines between two rubber rows at 18 m distance) and single row (one agarwood line
between two rubber row at 12 m distance) in 2 ha land of Rubber Research Institute, Agalawatte.
G. walla is native to Sri Lanka and two Aquilaria species were introduced from Vietnam and
Thailand respectively. Due to the fast growth rate, 50% and 30% shade settings were not applied
for both Aquilaria species. Total tree height and stem diameter (above 30 cm of the ground) were
collected from all (167) agarwood producing species in all two systems at monthly intervals.
Data were statistically analysed after three years by one-way ANOVA using Minitab software.
According to the results, both Aquilaria species grown in all systems recorded significant height
and diameter growth than G. walla. There was no significant height or diameter growth
difference between two Aquilaria species under full sun in both double row and single row
systems. There was also no significant height or diameter growth difference between G. walla
under all shades setting in all systems. Therefore the study revealed that the growth potential of
G. walla is noticeably lower than selected Aquilaria species when intercropped with rubber.
