Forestry- Department of wood science

The study revealed significant variation in physical and mechanical properties of wood of shisham (Dalbegia sissoo) collected from different timber market sites. The maximum moisture content (20.170%) was observed in the wood samples of Nalagarh site. Highest specific gravity of (0.644) was observed in Dattowal and lowest (0.748) in Nalagarh site. Maximum vessel diameter (0.126 mm), fibre diameter (0.020 mm) and fibre length (1.66 mm) was found in the wood samples from Ghumarwin, Dattowal and Ghumarwin respectively.

The study shows the variation in the chemical properties of jackfruit wood in which the properties like cold water solubility, hot water solubility, alcohol benzene extractives, cellulose, hemicellulose, holocellulose, klason lignin, NaOH soluble extractives and ash content are being determined. The quality and utility of the woods obtained from different zones are thus being analysed and the data can further be used for utilization of jackfruit wood.

The study physical properties of jack wood plays an important role providing its strength and durability and also for its utilization in various aspects. The properties like the colour parameters (L* value, a* value and b* value), texture, moisture content, green specific gravity, oven dry specific gravity and shrinkage (volumetric, tangential and radial) were taken into account. The analysis revealed significant differences between the zones for shrinkage (volumetric, tangential and radial) between three zones while rest of the properties showed non-significant results between the three zones and girth classes within these zones. The strength and durability of the woods obtained from different zones are thus being analysed and the data could be further used for utilization of jack wood.

The present research entitled “Wood property variation in jack trees (Artocarpus heterophyllus Lam.) grown in Thrissur district, Kerala" was carried out in the Department of Forest Products and Utilization, College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, during 2017-2020. The species belonging to the family Moraceae and popularly known as jackfruit tree, is one of the important timber species commonly found in the home gardens of Kerala. The objective of this study was to assess the variation in physical, chemical, anatomical and mechanical properties of Jack wood (Artocarpus heterophyllus Lam.) between different altitudinal zones (Lowland, Midland and Highland) and girth classes within these altitudinal zones of Thrissur district, Kerala.
Samples of Jack wood were collected from the three altitudinal zones (Lowland, Midland and Highland) of Thrissur district belonging to three girth classes viz., 30 cm - 60 cm, 60 cm - 90 cm. and 90 cm -120 cm, following stratified random sampling techniques.  In the case of physical properties such as color, moisture content, green specific gravity, oven dry specific gravity, volumetric shrinkage, tangential shrinkage and radial shrinkage, analysis showed variation between the zones for the all the three types of shrinkages. Chemical analysis of the wood for water soluble and chemically soluble extractives showed significant variation in the case of alcohol benzene soluble extractives and for NaOH soluble extractives. Rest of the parameters such as cold-water soluble extractives, hot water-soluble extractives, holocellulose content, klason lignin content, cellulose content, hemicellulose content and ash content showed no significant variation. Jack wood is diffuse porous with aliform parenchyma surrounding solitary vessels, sometimes forming bands and broad to finely arranged rays.  The anatomical parameters when analyzed, showed significant variation for ray morphological characteristics whereas vessel morphology, fibre morphology and ecoanatomical properties showed no significant variation. The mechanical parameters studied which includes static bending, tension, compression and its sub parameters showed no significant variation except for Modulus of elasticity compression perpendicular to grain.
Simple correlation coefficients obtained between physical and chemical parameters, four were found to be positive and significant at 1% level of significance, two were found to be positive and significant at 5% level of significance whereas, one was reported as negatively correlated and significant at 1% and one was reported as negatively correlated and significant at 5% level of significance. The simple correlation coefficients obtained between physical and anatomical parameters, three were found to be positive and significant at 1% level of significance, two were found to be positive and significant at 5% level of significance whereas, one was reported as negatively correlated and significant at 1% and one was reported as negatively correlated and significant at 5% level of significance. Simple correlation coefficients obtained between physical and mechanical parameters, twenty were found to be positive and significant at 1% level of significance, ten were found to be positive and significant at 5% level of significance whereas, one was reported as negatively correlated and significant at 1%. The simple correlation coefficients obtained between chemical and anatomical parameters, one was found to be positive and significant at 5% level of significance, one was found to be negative and significant at 5% level of significance whereas, one was reported as negatively correlated and significant at 1%. Simple correlation coefficients obtained between chemical and mechanical parameters, eleven were found to be positive and significant at 1% level of significance, nine were found to be positive and significant at 5% level of significance whereas, one was reported as negatively correlated and significant at 5%. The simple correlation coefficients obtained between anatomical and mechanical parameters, eight were found to be positive and significant at 1% level of significance, three were found to be positive and significant at 5% level of significance whereas, three was reported as negatively correlated and significant at 5%. Coefficient of determination (R2) was observed to be more than 0.70 for oven dry specific gravity, tangential shrinkage and radial shrinkage when regressed with physical and chemical parameters. When regressed between physical and anatomical parameters R2 was observed to be more than 0.70 for green specific gravity, tangential shrinkage, radial shrinkage and volumetric shrinkage. Coefficient of determination (R2) was observed to be more than 0.70 for green specific gravity, tangential shrinkage, radial shrinkage and volumetric shrinkage when regressed with physical and mechanical parameters.

The interrelationships between different wood properties were carried out to check the dependence of one character over the other which defines the overall quality and performance of the jack wood Highly significant and positive correlation was noticed for a*value with ash content; volumetric shrinkage with green specific gravity; tangential shrinkage with radial shrinkage; holocellulose content with hemicellulose content. The negative and significant correlation has been recorded for L*value with a*value; green specific gravity with NaOH soluble extractives content. Highly significant and positive correlation was noticed for volumetric shrinkage with tangential shrinkage and radial shrinkage; tangential shrinkage with radial shrinkage; oven dry specific gravity with vessel area and ray width. The negative and significant correlation has been recorded for L*value with a*value, tangential shrinkage with fibre diameter. Highly significant and positive correlation was noticed for parameters related to physical and mechanical wood parameters except for The negative and significant correlation has been recorded for L*value with a*value, tangential shrinkage with fibre diameter. Regression studies also showed considerable relationships between the physical, chemical, anatomical and mechanical properties.

Attempt was made to evaluate the wood variation in Dalbergia sissoo (shisham) from the local markets of Himachal Pradesh. The highest moisture content (20.17%) was observed in the wood samples of Nalagarh site. Highest specific gravity of 0.644 was observed in Dattowal and lowest (0.748) in Nalagarh site. Significant variation in mechanical properties was observed for all the studied parameters. The maximum bending strength was recorded in Baroh and Sundernagar site (0.006 kN/mm2) and maximum tensile strength (0.094 kN/mm2) was noticed in the wood samples from Baroh site. The maximum compressive strength parallel to grain (0.069 kN/mm2) was observed in Kangu site and maximum compressive strength perpendicular to grain (0.038 kN/mm2) was found in Baroh site. The maximum modulus of elasticity parallel to grain (0.231 kN/mm2) was recorded in Ghumarwin and maximum modulus of elasticity perpendicular to grain (1.653 kN/mm2) was noticed in wood samples of Galore site. The greater modulus ...