Assessment of Hydraulic Conductivity of Some Nigerian Hardwood Timbers to Four Timber Treatment Chemicals through Quantitative Anatomical Studies

Aim: Hydraulic conductivity following the Hagen-Poiseuille Law is a quantitative approach to determine the treatability of wood by chemicals. The hydraulic conductivities of the ten selected Nigerian hardwood timber species to four wood treatment chemicals were estimated, using Hagen-Peiseuille equation.

Materials and Methods: Ten timber species of marketable size and age were sourced from the forestry Departments of Enugu, Anambra and Abia States of Nigeria. Maceration were carried out following standard procedures. The viscosities in centipoises (cp) of the four wood treatment chemicals were measured in a viscometer test, while the hydraulic conductivities were calculated using the Hagen-Peiseuille equation.

Results: The results obtained show that the different woods responded differently to the chemicals. Treatment with Folithion 200 showed higher conductivity in Triplochiton scleroxylon (9.01 mm-3S-1× 10-5), followed by Mansonia altissima, Milicia excelsa and Terminalia superb. The order of conductivity to treatment with Actellic 25EO was Terminalia superba > Mansonia altissima > Gmelina arborea, > Khaya ivorensis. Ceiba pentandra gave the highest conductivity of 8.58 mm-3S-1× 10-5, followed by Afzelia africana and Canarium schwenfurthii to the chemical Termitox. While Triplochiton scleroxylon gave the highest conductivity of 6.52 mm-3S-1×10-5, followed by Milicia excels and Terminalia superba to the chemical Solignum.

Conclusion: Folithion 200 would be effective on Milicia excels, Mansonia altissima and Gmelina arborea, Actellic 25 EO would be effective on Khaya ivorensis, Terminalia superb and Antiaris toxicaria while Termitox would be effective on Ceiba pentandra, Afzelia Africana and Canarium schweinfurthii.