Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia septum is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G.sepium at three intervals according to age groups (three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years of age as compared to five (0.4 I) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively,, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.


BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5696-5709
Author(s):  
Ali Hassanpoor Tichi ◽  
Habibollah Khademieslam ◽  
Mojtaba Rezanezhad Divkolae

Three healthy Citrus sinensis (orange) trees in Babol, Iran, were randomly selected and cut. Two discs of 5 cm thickness were prepared along the tree (breast height and crown). In the transverse direction, the test specimens were cut 2 × 2 cm to 3 cm from the pith to the bark sequentially and examined. The biometric and physical properties were measured, and microscopic sections of wood near the bark were studied using light microscopy according to the International Association of Wood Anatomists’ (IAWA) List. Anatomical examination of the C. sinensis wood showed that the species was a diffuse porous hardwood, with indistinct growth rings, simple perforation plates, alternate intervessel pits, and banded parenchyma. The basic density and oven-dry density increased from the pith towards the tree bark and from the bottom of the tree towards the crown. There was a significant difference in both the transverse and longitudinal directions of the C. sinensis tree in terms of fiber length, fiber lumen diameter, fiber diameter, and cell wall thickness. The mean fiber length, fiber diameter, fiber lumen diameter, and cell wall thickness were 0.76 mm, 23.64 µm, 9.23 µm, and 14.41 µm, respectively.


2011 ◽  
Vol 236-238 ◽  
pp. 2449-2459
Author(s):  
Xiao Ping Fan ◽  
Zhi Feng Meng ◽  
Jia Hua Zhou ◽  
Hong Xiang

Major factors that influenced the breakage of starch bubbles during extrusion expansion such as the initial bubble radium, the initial cell wall thickness, the initial cell wall temperature, the initial cell wall moisture content, the stress strength constant of starch and the changes of failure stress of bubble wall, stress of bubble wall, bubble radium, cell wall thickness, pressure different with time were investigated and the critical breaking points for each operation parameters under certain conditions were determined. The results showed that the smaller the initial bubble radium, the higher the initial cell wall thickness, and within certain range, the lower the initial temperature, the lower the initial moisture content, and the higher the stress strength constant of starch, the lower the tendency the bubble broke.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4913
Author(s):  
Ewa Tulska ◽  
Monika Aniszewska ◽  
Arkadiusz Gendek

The objective of the study was to elucidate the kinematics of cone opening in the European larch (Larix decidua Mill.) during a four-step seed extraction process and to determine optimum process time on that basis. Each step lasted 8 h with 10 min of water immersion between the steps. The study also described the microscopic cellular structure of scales in cones with a moisture content of 5% and 20%, as well as evaluated changes in cell wall thickness. The obtained results were compared with the structural investigations of scales conducted using scanning electron microscopy (SEM) of characteristic sites on the inner and outer sides of the scales. The greatest increment in the scale opening angle was noted on the first day of the process (34°) and in scales from the middle cone segment (39°). In scales with a moisture content of 5% and 20%, the greatest changes in cell wall thickness were recorded for large cells (57%). The inner and outer structure of scales differed in terms of the presence and size of cells depending on the moisture content of the cones (5%, 10%, or 20%). The study demonstrated that the moisture content of cones was the crucial determinant of the cellular structure and opening of scales in larch cones. The scale opening angle increased with decreasing moisture content but did not differ significantly for various segments of cones or various hours of the consecutive days of the process. This finding may lead to reducing the seed extraction time for larch cones. The internal and external structure of scales differed depending on moisture content, which also determined the size and wall thickness of cells.


FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 910
Author(s):  
Elder Eloy ◽  
Rômulo Trevisan ◽  
Tainara Dos Santos Piecha ◽  
Magda Rosa Fontoura ◽  
Henrique Webber Dalla Costa ◽  
...  

Drying is an important process in the generation of wood products, as it increases the quality of the final products; however, it is influenced by various anatomical characteristics. The aim of this study was to evaluate the influence of anatomy on the drying of wood of Parapiptadenia rigida (Benth.) Brenan, Peltophorum dubium (Spreng.) Taub., Eucalyptus grandis W. Hill × Eucalyptus urophylla S.T. Blake (hybrid), and Schizolobium parahyba (Vell.) Blake trees from an agroforestry system. Three trees aged 9 years were sampled for each species. The trees were removed from the study region when their diameter at breast height (DBH) was 1.30 m from the ground. Blocks were made with dimensions of 5.0 × 5.0 × 15.0 cm for the evaluation of oven drying and 1.5 × 1.5 × 2.0 cm for anatomical features. S. parahyba has the highest value of fiber diameter (35.1 µm) and lumen diameter (27.6 µm), whereas P. dubium had the highest value of cell wall thickness (6.8 µm). The average equilibrium moisture content was 10.98% after 40 days of drying. The anatomy of the wood influenced the drying of the four species intensity, which was related to humidity during all periods. The anatomical parameters that most influenced drying were fiber diameter (Pearson correlation coefficient: 0.77), lumen diameter (0.76), and fiber cell wall thickness (0.73); the higher the values, the greater was the drying intensity.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 830
Author(s):  
Mingyue Li ◽  
Shuangbao Zhang ◽  
Yurong Wang ◽  
Haiqing Ren

Shear strength is important for the application of Larix kaempferi (Lamb) Carr. The structural difference between earlywood and latewood of Larix kaempferi affects its mechanical properties, especially shear strength. The microstructures of earlywood and latewood in Larix kaempferi, however, are different. In this study, we investigated the shear strength and shear failure mode in the RL direction of 40 Larix kaempferi specimens. The results demonstrated that the initial crack appears in any location of a growth ring, whereas shear failure is concentrated in earlywood, as well as the junction between earlywood and latewood. The destruction of earlywood is the tear destruction, whereas when the destruction happened in the junction of earlywood and latewood, one to three earlywood cells usually adhered to latewood. At the cell wall level, the shear failure of earlywood was mostly observed in the direction of the microfibril angle (MFA). When the crack occurs in latewood, the destruction of latewood also occurs in the intercellular layer and preserves the complete morphology of tracheids. When destruction occurs in the wood ray, the ray cells detach intact from the tracheids. The failure mode is determined by the microstructure of earlywood and latewood. Our research suggests that the density, cell wall thickness, and MFA have significant differences between earlywood and latewood. The earlywood was found to have an MFA of 25.4°, a cell wall thickness of 6.36 µm, and a density of 0.39 g/cm3. The MFA, cell wall thickness, and density of latewood density were 17.60°, 12.37 µm, and 0.78 g/cm3, respectively. However, there was no significant difference found in the crystallinity between the earlywood (43.97%) and latewood (42.79%). The correlation between the microstructures and shear strength showed that earlywood with a thin cell wall, large MFA, and low density had poor shear performance, while the latewood with a thicker tracheid, smaller MFA, and higher density had better shear performance. Therefore, when shear failure occurred, it occurred in earlywood. We thus deduced that the MFA, cell wall thickness, and density of earlywood synergically affect the shear strength in the RL direction of L. kaempferi.


Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 449-460 ◽  
Author(s):  
H. Mäkinen ◽  
P. Saranpää ◽  
S. Linder

Summary To study the effect of growth rate on fibre characteristics and their variations in Norway spruce, trees were sampled in a nutrient optimisation experiment in northern Sweden. Data was collected from 24 trees (40 years old) from fertilised and control plots after 12 years of annual nutrient application, as well as from older trees outside the experimental area. Fibre length, fibre diameter, cell wall thickness, lumen diameter and cell wall percentage were measured from every third annual ring at breast height and at a height of 4 m. Fibre properties, as well as their standard deviation, were closely related to ring number and distance from the pith. Intra-ring variation of fibre characteristics was high compared to their variation between trees. Fertilisation reduced fibre length and cell wall thickness, but increased fibre and lumen diameter in rings of the same age. The difference in fibre width, cell wall thickness and lumen diameter between fertilised and control trees was less apparent, but a greater difference in fibre length was found between the treatments with regard to distance from the pith. There was a similar effect of fertilisation on fibre properties in early- and latewood. The effect of enhanced growth rate was less pronounced at a height of 4 m (near the pith) than at breast height (in older rings). It was demonstrated that it is possible to model intra-tree variability of fibre characteristics using ring width and cambial age as independent variables. Models presented are, however, limited by the relatively young age of the sample trees used.


Holzforschung ◽  
2007 ◽  
Vol 61 (3) ◽  
pp. 301-310 ◽  
Author(s):  
Tuula Jaakkola ◽  
Harri Mäkinen ◽  
Pekka Saranpää

Abstract The effects of the intensity and timing of commercial thinning and fertilisation on tracheid properties and lignin content of Norway spruce [Picea abies (L.) Karst] were studied in two long-term fertilisation-thinning experiments in central and eastern Finland. The experiments consisted of three thinning and three fertilisation treatments in a randomised block design. Fertilisation levels were: unfertilised (F 0), 150 kg N ha-1 (F 1), and 300 kg N ha-1 (F 2). Thinning treatments were: delayed first thinning (T 0), normal thinning (T 1), and intensive first thinning (T 2). A total of 85 trees were sampled 26 years after treatment onset. Tracheid length was measured for 24 trees and cell wall thickness and lumen diameter for 16 trees grown under treatments F 0 T 0, F 0 T 2, F 1 T 0, and F 1 T 2. Lignin content was determined for all trees sampled (n=85) grown in all the different treatment combinations. We found only small differences in tracheid length (0–6%), cell wall thickness (1–17%) and lumen diameter (0–9%), depending on the different fertilisation and thinning conditions. We also found only slightly (1–2%) higher lignin content for fertilised (F 1 and F 2) than for unfertilised (F 0 ) trees (25.8% and 26.0% vs. 25.4%). Trees yielded 26.0% lignin content after intensive first thinning (T 2), 25.9% following normal thinning (T 1), and 25.4% after delayed first thinning (T 0). Thus, the prevailing fertilisation and thinning practice for Norway spruce stands in Finland may not cause essential changes in tracheid properties and lignin content.


Holzforschung ◽  
2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Takato Nakano

Abstract The relationship between inward and outward swelling of cell wall surfaces was examined. A formula was derived based on a cylindrical model of a wood cell. The equation clarifies that the slope of the swelling ratio of the whole wood versus moisture content is governed by a number of factors. This equation allows the examination of how the swelling direction of cell wall surfaces is determined during water adsorption. The swelling direction is given by the parameter Δh/Δr, where Δh is the increase of cell wall thickness as a result of inward and outward swelling and Δr is the outward increase.


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