THE STUDY OF THE MOTORS AFFECTING THE NATURAL RESISTANCE OF THE WOOD OF TERMINALIA IVORENSIS AGAINST TERMITE ATTACK

ABSTRACT

The natural Radial and axial variations in the resistance

of the wood of Termihalia ivorensis A* Chev, against

damage by subterranean termites were investigated for two

trees from the same locality- The damage was studied in

relation to specific gravity, the modulus of elasticity,

the cross-sectional area of vessels in the wood,, and the

water soluble extractives. The correlation between termite

damage and these physical, mechanical and anatomical

properties have been reported.

It was found that the termite resistance of the wood

varied significantly in the radial direction. The outerheartwood

was less susceptible to damage than the sapwood

and the inner-heartwood, The sapwood was less resistant

to damage than the inner-heartwood. The termite resistance

of the inner-heartwood increased near the top of the tree.

Axial variations in the intensity of termite damage were

not very pronounced.

Termite damage to the wood was inversely correlated

with the specific gravity and cross-sectional area of the

vessels generally. The susceptibility to damage by termites

generally increased with the modulus of elasticity.

The specific gravity, modulus of elasticity and the crosssectional

area of the vessels were inter-correlated and no

one of them could be used alone to predict the termite

resistance of T, ivorensis, The water soluble extractives

appeared not to improve on the resistance of the wood.

The two trees tested showed significant differences

in their resistance to termite attack. This means that

naturally growing trees of T„ ivorensis obtained from

different Forest Reserves in Ghana could be expected to

vary widely in their resistance against attack by subterranean

termites.