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Teak (Tectona grandis) is one of the highly demanded timber spe-
| cies in Sri Lanka. When buying teak logs, customers assess their quality by
p visual appraisal of surface characteristics such as visible defects. Hence, the
p buyers’ preference for logs with desired attributes is reflected by the price
s achieved in the market. In this study, we examined the influence of visually
I observable quality attributes of plantation grown teak logs on their market
| price. A set of 650 randomly selected teak logs were assessed for dimen-
| sions, shape defects, surface defects and end-defects. Length of the log,
p mid-circumference (under bark), diameter at top-end and butt-end, number
I of knots per meter, average diameter of the knots, bend fraction, percentage
I of heartwood, shape of the log, presence of buttress, position of the hollows,
1 presence of felling damages, splits and heart rot were recorded using standI
" aid methods. Selling prices of logs were obtained from the records of log
storing facilities. By using the multiple linear regressions, a price-quality
model was developed to explain the impact of quality attributes on selling
price. The regression model achieved a strong coefficient of determination
(R!) of 0.87. Accordingly, the length, mid-circumference, number of knots
per meter, bend fraction, hollow position, presence of buttresses and presence of heart rot were found to have a significant influence on the price.
The relative price reduction due to presence of a specific log defect was
further examined using the derived price-quality model. The presence of
high number of knots had the highest detrimental impact on price, followed
by the higher bend fraction, presence of hollows at top end and/or middle of
the log, presence of heart rot and presence of buttresses respectively. These
findings have implications in the improved management of teak plantations.
