Yield modeling in sawing logs of Manilkara spp. (Sapotaceae) in sawmill in the state of Roraima, Brazil

Abstract

The aim of this study was to estimate the yield of sawing Manilkara spp. logs, to quantify the wood by products generated, to evaluate differences in the yield between the diameter classes and to adjust models to estimate the yield in lumber and to estimate the volume of the hollow part of the logs. Seventy-one logs were sampled and grouped into diameter classes. Log volumes were determined by the Smalian method and the volume of lumber was calculated to determine the yield. Twelve models were tested to estimate the sawn lumber and twelve models to estimate the volume of the hollow logs. The choice of the best models was made based on the highest adjusted coefficient of determination (Rajust2), lowest standard error of estimate (Syx%) and homogeneous distribution of the residues. The average yield was 30.1% and showed no statistical differences in yield between the diameter classes and between hollow logs and non-hollow logs. Class 5 (70<79,9 cm) was the one that presented the best yield. To estimate the yield, the best equation was the number seven. To estimate the volume of the hollow part of the logs, the best equations were number two, three and ten.