SHARMA, KULWANT RAIM S, DEEPA2019-11-022019-11-022019-08http://krishikosh.egranth.ac.in/handle/1/5810133832ABSTRACT The present research entitled “Vertical variation in wood properties of Acrocarpus fraxinifolius Wight & Arn.” was carried out in the Department of Forest Products, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan (HP). Twenty-nine year old Acrocarpus fraxinifolius’ tree, felled and divdid into 10 logs of total bole height to investigate the physical, chemical and strength properties of the wood. It showed significant variation along the bole height. The values of diameter, bark percentage, sapwood percentage and heartwood percentage were ranged between 19.70 cm to 34.44 cm (from 90% to base), 1.16 per cent (90%) to 2.20 per cent (base), 47.46 per cent (base) to 34.71 per cent (top), 51.38 per cent (90%) to 63.08 per cent (base), respectively. In sapwood moisture content was maximum at 90 per cent (92.6%) and minimum was recorded at base (66.79%) and for specific gravity maximum was recordrd from base (0.578) and minimum was recorded from 90 per cent (0.487). The maximum fibre length was recorded at base (1.18 mm) and minimum at 90 per cent (1.02 mm) of total bole height. In heartwood moisture content, specific gravity and fibre length ranged between 45.58 per cent (base) to 67.18 per cent, 0.596 (90%) to 0.718 (base) and 1.16 mm (base) to 0.99 mm (90%), respectively. In sapwood, the coldwater extractives, hotwater extractives, Alcohol-Benzene extractives, holocellulose content, lignin content and ash content ranged between 3.94 per cent (90%) to 4.7 per cent (base), 6.12 per cent (90%) to 6.7 per cent (base), 8.53 per cent (90%) to 11.17 per cent (base), 68.06 per cent (base) to 73.21 per cent (90%), 21.32 per cent (90%) to 26.03 per cent (base) and 0.75 per cent (base) to 1.21 per cent (90%) of total bole height, respectively. In heartwood, the coldwater extractives, hotwater extractives, AlcoholBenzene extractives, holocellulose content, ligin content and ash content were ranged between 4.42 per cent (90%) to 4.85 per cent (base), 7.32 per cent (90%) to 7.92 per cent (base), 11.08 per cent (90%) to 12.24 per cent (base), 67.91 (base) to 70.42 per cent (90%), 25.92 per cent (90 %) to 28.80 per cent (base) and 0.6 (base) to 0.96 per cent (90%) of total bole height, respectively. The tensile strength, bending strength, compressive strength parallel to grain, compression strength perpendicular to grain, bending modulus of rupture, modulus elasticity in tensile strength, modulus of elasticity in bending strength, modulus of elasticity compression parallel to grain, modulus of elasticity compression perpendicular to grain were ranged between 0.044 kN/mm2 (90%) to 0.069 kN/mm2 (base), 0.0087 kN/mm2 (80%) to 0.013 kN/mm2 (base), 0.0147 kN/mm2 (50%) to 0.075 kN/mm2 (60%), 0.183 kN/mm2 (base) to 0.220 kN/mm2 (80%), 0.724 kN/mm2 (30%) to 2.294 kN/mm2 (10%), 5.577 kN/mm2 (90%) to 8.978 kN/mm2 (base), 0.620 kN/mm2 (10%) to 0.359 kN/mm2 (60%), 0.081 kN/mm2 (10%) to 0.022 kN/mm2 (50%).ennullThesis