Solid hardwood flooring resistance to termites (Coptotermes curvignathus) under laboratory condition

Hardwood flooring is generally manufactured using solid timbers because they can withstand harsh weather conditions and are more resistant to pest attack. In Malaysia, a major pest to timber structures is the subterranean termites. To prevent wood degradation by termites, chemical preservatives have been applied to wood. However, this practice is not environmentally friendly and may be hazardous to humans, thus creating the demand for naturally durable wood. In this study, the durability of six local and three foreign tropical hardwoods against Coptotermes curvignathus were tested in the laboratory. Untreated solid hardwoods were each cut into replicate test wafers of 25 mm square by 6 mm in the radial direction and were exposed to 400 termites (360 workers and 40 soldiers) in culture bottles following AWPA El-97 protocols. After four weeks, visual rating, mass loss of each sample and termite mortality were determined. All the test samples subjected to C. curvignathus had 100% mortality rate, sample weight losses of 3.30-8.52%, and a minimum visual rating of 9.0 at the end of a 4-week test. There was a weak correlation between specific gravity and mean mass loss of the samples. Our results suggest that local hardwood species 'bids' (Madhuca utilis) and 'kekatong' (Cynometra malaccensis), and a foreign species 'pyinkado' (Xylia dolabriformis) are highly resistant to C. curvignathus attack and could be used as flooring materials without chemical treatment

Trends in Seaweed Research

This is a letter on the evolution of trends in seaweed research with respect to the development of technology and generation of knowledge, as well as difficulties and future perspectives in seaweed research

Evaluation of Trichoderma asperellum as a potential biocontrol agent against Rigidoporus microporus Hevea brasiliensis

White root disease caused by Rigidoporus microporus is the most devastating disease in majority of the rubber growing countries, including Malaysia. This study aimed to screen and decipher the mechanisms involved in the biocontrol agents responsible for the inhibition of R. microporus. Among 16 fungal isolates, Trichoderma spp. showed promising results with the highest percent of inhibition shown by Trichoderma asperellum (80.54%). Scanning electron microscopy study revealed coiling of hyphae by Trichoderma species against R. microporus. T. asperellum has demonstrated a maximum inhibition in both volatile and non-volatile metabolite tests with its 75% culture filtrate on PDA plate was observed to cause abnormal morphological character in R. microporus. All Trichoderma species were shown to produce hydrolytic enzymes (chitinase, cellulase and β-1,3-glucanase) and they were active siderophore producers. Present study demonstrated the possible mechanisms involved and responsible for successful inhibition of R. microporus under in vitro condition especially by T. asperellum

Effect of post-thermal treatment on the density profile of rubberwood particleboard and its relation to mechanical properties

The objective of the study was to investigate the effect of heat treatment on the changes in density profile of rubberwood particleboard samples. The relationship between density profile and mechanical properties of particleboard samples was determined using regression analysis. Single layer particleboard made from rubberwood particles with dimensions of 340 mm × 340 mm × 12 mm and targeted density of 700 kg m-3 was heat-treated using oven and hot press at three different temperature levels, namely, 100, 150 and 200 °C for 30 min. All density profile attributes were significantly affected by heat treatment. Bending properties, internal bond strength and hardness were influenced by treatment temperature. However, samples treated using hot press had better mechanical properties compared with those treated using oven. Mean and peak densities exerted profound effects on mechanical properties of the samples

Valorization of waste oil palm (Elaeis guineensis Jacq.) biomass through furfurylation

Malaysia is the biggest producer of palm oil in the world. The production generates large amounts of waste trunks which should be considered a valuable bio-feedstock rather than waste. An approach for valorization of waste oil palm biomass – especially that of low density hardly applicable in industry – through furfurylation was investigated. Furfuryl alcohol treatment resulted in great improvement in the properties of the material: 200% density gain, water absorption and thickness swelling reduced by 50% and 74%, respectively, hardness increased by 400%, as well as 3.5-fold and 7.4-fold increase, respectively, in bending strength and modulus of elasticity was observed. Alternations in physical and mechanical properties of oil palm trunk combined with aesthetic changes due to material darkening may be considered an effective approach for conversion of waste biomass to novel materials of enhanced technical value

Oil palm (Elaeis guineensis) trunk as a resource of starch and other sugars

Large quantities of oil palm trunks are available annually during the replanting activities when the oil palm tree passed their economic age, on an average after 25 years are replace with young trees. Basically the oil palm trunks contains about 18- 21% of lignin, 65-80% of holocellulose (a-cellulose and hemicellulose) and quite significant amount starch. This work is aimed to determine the total extractable starch and sugars content from oil palm trunks by using steeping method and dilute acid hydrolysis. The effect of different oil palm trunk powder size on starch, xylose and glucose yield was evaluated. The effect of extraction parameter for each extraction method on the yield of starch and sugars were studied. The highest starch yield was obtained when steeped in the presence of lactic acid, while the highest xylose yield was obtained by 60 min hydrolysis of 60 mesh of oil palm powder with 2% sulfuric acid. For glucose yield, hydrolysis efficiency of 82% was obtained for conversion of oil palm trunk to glucose using two-stage concentrated sulfuric acid hydrolysis. Conclusively oil palm trunk can be considered as a resource of substantial amounts of starch and sugars

Compost feedstock characteristics and ratio modelling for organic waste materials co-composting in Malaysia

In Malaysia, large amounts of organic materials, which lead to disposal problems, are generated from agricultural residues especially from palm oil industries. Increasing landfill costs and regulations, which limit many types of waste accepted at landfills, have increased the interest in composting as a component of waste management. The objectives of this study were to characterize compost feedstock properties of common organic waste materials available in Malaysia. Thus, a ratio modelling of matching ingredients for empty fruit bunches (EFBs) co-composting using different organic materials in Malaysia was done. Organic waste materials with a C/N ratio of<30 can be applied as a nitrogen source in EFB co-composting. The outcome of this study suggested that the percentage of EFB ranged between 50% and 60%, which is considered as the ideal mixing ratio in EFB co-composting. Conclusively, EFB can be utilized in composting if appropriate feedstock in term of physical and chemical characteristics is coordinated in the co-composting process

Effect of using agro-fertilizers and N-fixing Azotobacter enhanced biofertilizers on the growth and yield of corn

Corn is an important crop and is grown widely around the world. Corn is a food source for human as well as animal and processed into industrial product such as ethanol. Corn is one of the important productions of Malaysia as the climate is suitable for corn growth. In this study, organic fertilizers such as biofertilizer, N-fixing Azotobacter enhanced biofertilizers and compost were added to the soil to determine best practice in using organic fertilizers for higher corn yield and growth. The study was conducted in plot experiment with five replications based on randomized block design in the summer of 2012. All plots were manually harvested and yield was adjusted to 15% moisture. Grain yield (total corn harvested) at maturity was determined by harvesting the two central rows of each plot. Statistical analysis was performed on the effect of fertilizer treatments on plant growth, corn yield and nitrogen, phosphorous and potassium contents of plant materials. The means were compared according to Duncan multiple range test. The results showed that organic fertilizers in the form of N-fixing Azotobacter enhanced biofertilizer increased yield with positive effects on measured plant height, weight and leaf index. Given the significant enhancement in growth and yield of corn taking place mainly with N-fixing Azotobacter fertilizers under organic condition, the mechanism for this beneficial effect could be due to the more balanced nutrition and improved absorption of nitrogen and other mineral nutrients by the corn

Properties of particleboard with oil palm trunk as core layer in comparison to three-layer rubberwood particleboard

Compaction ratio is highly dependent on the density of the wood materials used in the production of particleboard. Lower density wood materials will produce particleboard with higher compaction ratio and is believed to give better properties. The objective of this study was to evaluate the properties of threelayer particleboard made from rubberwood and oil palm trunk with different bulk density as the core layer, while the rubberwood fine particles served as surface layers for both types of particleboard. This study also investigated the effect of shelling ratios on the mechanical and physical properties of the threelayer particleboard. Melamine-fortified urea formaldehyde (UF) resin was used as the binder. The modulus of rupture (MOR), internal bond strength (IB) and thickness swelling (TS) of the particleboards were evaluated based on the Japanese Industrial Standard for particleboard (JIS A 5908:2003). The results showed that both species and shelling ratios are variables that influenced the mechanical and physical properties of the particleboard. Despite its lower compaction ratio, particleboard made from rubberwood alone had better strength properties and dimensional stability than particleboard made from a mixture of rubberwood and oil palm trunk