INFLUENCE OF PROVENANCE VARIATION ON WOOD PROPERTIES OF TEAK FROM THE WESTERN GHAT REGION IN INDIA

The three major teak provenances of the Western Ghats in India were characterised in terms of mechanical and anatomical wood properties. Within the same age of 21-year-old plantations, teak from the North Kanara provenance, generally known to display slow growth, had the lower values of static bending (modulus of rupture and modulus of elasticity) and longitudinal compressive stresses than the Malabar provenance (Nilambur). The weaker timber of North Kanara provenance was attributed to its relatively high percentage of parenchyma and low percentage of fibres in the narrower rings, probably as an adaptation to nutrient-rich soil condition. Observations of 65-year-old plantations reveal that there was a trend for bending stiffness (modulus of elasticity) and maximum stress (modulus of rupture) of the timber to be highest towards the southernmost geographic location (Konni) within the latitudinal range of 9° to15° S with a greater percentage of cell wall (with higher lignification) despite the slower growth rate and well defined ring-porosity with wider bands of earlywood parenchyma tissue. The study thus underlines the need to recognise the provenance source of variation to explain the varied growth-structure-property relationships of teak and to utilise the Indian genetic resources to the optimum in future teak improvement programmes.