Treatability indices of some plant species of fabaceae in Nigeria
The hydraulic conductance as estimated by Hagen Poiseuille equation was tested on five Nigerian timber species: Brachystegia nigerica, Afzelia africana, Periscopsis elata, Erythrophleum suaveolens, and Daniella oliveri using spent-engine oil (SAE 40), diesel, kerosene and solignum. The wood of Brachystegia nigerica and Afzelia africana gave more conductance (penetrability) to kerosene, diesel, solignum and spent-engine oil than the other three. The wood of Brachystegia nigerica and Afzelia africana gave the highest vessel lumen radius of 0.18±0.06 mm and 0.12±0.01 mm respectively, while Daniella oliveri, Erythrophleum suaveolens and Pericopsis elata gave the lowest vessel lumen radius 0.09 ± 0.01 mm, 0.07±0.01 mm and 0.05±0.002 mm respectively. The less viscous oils: kerosene, solignum and diesel with viscosities 0.015, 0.019, and 0.043 centipoises respectively at 28°C showed more penetrability than the more viscous spent-engine oil of 2.92 centipoises. There is a positive correlation between the vessel lumen radius and hydraulic conductivities of the four treatment fluids (P ≥ 0.05).