Authors : K. Okunomo , F.O. Achoja , O.M. Agbogidi and A.T. Onosode
Abstract: The conversion efficiency and the estimation of plank yield of three wood species (Danta, Alstonia and Obeche), were investigated using quantitative techniques. Ten logs of each of the three species, making a total of 30 logs were surveyed in ten sawmills in Delta State, Nigeria. Log length (m) lumber volume before miling (V1) and after milling (V2) were determined. Plank yield was determined to be (V2), while, volume of residue (waste) was determine by subtracting V2 from V1. Data collected were analyzed using quantitative techniques. The findings showed that Danta has the highest conversion efficiency of 59.08%, while, Obeche was the least in conversion efficiency of 50.89%. The result also revealed that the estimation equation for the three timber species performed well based on the values of R2 and R2 (adj.) of the multiple regression model. The result further revealed that there is negative and significant relationship between plank yield per log and the residue (waste) generated in the three species of timber surveyed. The study showed that though there is positive relationship between log size and plank yield per log, such correlation is not significant in the three models. Hence, log size is not a reliable estimator of plank yield per log. This could be due to the possibility of log deformities. On the basis of the findings, it was recommended that the rate of residue generation and deformities which tend to reduce plank yield per log should be the major factors to be considered in determining the quality and prices of logs of Danta, Alstonia and Obeche.
K. Okunomo , F.O. Achoja , O.M. Agbogidi and A.T. Onosode , 2007. Economics of Wood Conversion Efficiency and Plank Yield Estimation among Different Wood Species . Agricultural Journal, 2: 726-730.