Search

Paddy husk (PH) is a waste item generated from rice production that can be used as an organic fertilizer through composting. High lignin content is an issue with PH composting as it impedes the production of high-quality organic fertilizer. Improvements to the composting process can enhance the agronomic properties of compost produced from PH. The objectives of this study were to: (i) determine the ability of Bacillus spp. in enhancing the decomposition of PH and (ii) determine the ability of Bacillus spp. in increasing the macronutrient content of composted PH. Different ligninolytic active Bacillus spp. from termite gut (either singly or a cocktail) were added to 7 of 9 compost boxes containing PH compost mixtures and were allowed to decompose for a period of 60 days. Each treatment was represented by 3 samples, and the compost boxes were arranged in a completely randomized design (CRD) with 3 replications. Results showed that the addition of Bacillus spp. promoted the production of matured compost within 60 days with significantly higher amounts of phosphorus, potassium, calcium, and magnesium. Germination index (GI) of all composted PH added with Bacillus spp. ranged from 82.51 to 95.83%, suggesting that composted PH has lower phytotoxicity than compost without Bacillus spp. isolate. In general, addition of Bacillus spp. to PH waste promoted the production of PH composts with improved macronutrient availability and lower phytotoxicity levels.

Oil palm bunch moth, Tirathaba mundella Walker is a notorious bunch feeding pest typically among oil palm aged 3-7 years old planted on peat. In order to manage the pest, an economic injury level (EIL) for the pest needs to be determined which could assist in decision-making if a control tactic is justified. In order to determine the EIL, the percentage of fertile oil palm fruitlets and oil to bunch content were determined for fruit bunches with different pest infestation severity. The severity was characterised based on the mean larvae present in fruit bunches and male inflorescences. The study found that the mean larvae count was positively correlated with the economic losses and number of parthenocarpic fruitlets. The overall oil extraction rate (OER) of moderate and severely infested fruit bunches was significantly reduced as compared to clean fruit bunches. Based on average crude palm oil (CPO) market price and production per hectare, an EIL for T. mundella was able to be estimated. This study suggested the EIL at 10% of oil palms per hectare moderately or severely infested. The finding of this study would benefit future pest management practice in oil palm plantation established on peatland.

Tirathaba mundella Walker has emerged as one of the most prominent bunch feeding pests in Sarawak peat oil palm estates. Insecticides application is inevitable to prevent economic loss. However, to protect insect pollinators which cohabitat with the pest and reduce the risk of resistance development among the pest to insecticides, rotation treatments with more than one pollinator-friendly insecticides is recommended. This paper examines the effectiveness of rotating several pollinator-friendly insecticides in controlling the pest. To assess the effectiveness of different rotation combination, a field study on a seven-year-old peat estate was carried out using several insecticides combinations and application intervals, then the level of infestation post-treatment was assessed. Significantly, the results showed that only four single rounds of insecticides application in a year would yield relatively better control than nine rounds of Bacillus thuringiensis applications. Overall, there was no significant difference in clean bunches percentages obtained between five rounds of treatment compared to only four rounds per year. The result strengthens our confidence that the optimum and most cost-effective approach for one-year protection against T. mundella was two rounds of 30.0 g active ingredient of chlorantraniliprole per ha rotated with two rounds of 25.0 g active ingredient of chromafenozide. The material cost was calculated as RM 351.20 per ha per year. The findings of this study would benefit future pest management practice in oil palm plantation established on peatland.

Terung asam (Solanum lasiocarpum Dunal) is a native fruit vegetable that is gaining interest as a commercial crop in Sarawak and Malaysia. Malaysia is covered by soils that are highly weathered, acidic, and low in fertility and depend on chemical fertilisers to promote good plant growth. Alternative means to reduce dependency on chemical fertiliser, for example arbuscular mycorrhiza fungi (AMF), must be sourced. Very few research on terung asam has been documented particularly on nutrients uptake. The objectives of this research were to investigate the effect of indigenous and non-indigenous AMF on nutrient uptake by terung asam. A greenhouse experiment was conducted consisting of three treatments namely control (T1), indigenous AMF (T2), non-indigenous AMF (T3). The treatments were arranged in a complete randomised design with four subsamples and four replicates. Thirty-day-old seedlings were transplanted and measured for their heights and stem diameters for 90 days. Fresh and dry shoot and root weights were taken during harvesting. Plant nutrient analyses were conducted using Kjeldahl method for total N, single ashing for P and single ashing and double acid for K, Ca and Mg. The results revealed the addition of AMF spores at 200 spores per pot, increased plant height by 13 to 33% and stem diameter by 5 to 25% and more leaves were retained by T3 plants at harvesting. T3 recorded higher fresh shoot (11.27%) and dry shoot (14.98%) as well as fresh root (23.67%) and dry root (22.77%) weights than T1 plants. Addition of AMF in treatments T2 and T3 promoted better nutrient uptake by aboveground and belowground biomasses particularly for K, Ca and Mg. T3 was superior in terms of the nutrient uptake for most nutrients. AMF used in T3 showed better results as the AMF spores were proven effective in promoting plant growth while AMF used in T2 were obtained from the field and untested. The findings of this study showed the potential of indigenous and non-indigenous AMF in pr

Tropical mountain forests are vital components of global floristic diversity as well as the hydrological cycle but have been extensively exploited. However, the impacts of human disturbances on changes in biomass and regional forest variation are not well documented in tropical mountainous regions. This study was conducted on the Payeh Maga Highland, Sarawak, Malaysia thirty years after logging at three elevational zones namely upper dipterocarp forest (UDF), lower-montane oak-laurel forest (LOF), and upper montane forest (UMF). Stand and growth dynamics were assessed for 12 months to estimate the tree growth rate and the aboveground biomass (AGB) of logged and unlogged forests at various elevations. Significant differences between logged-over and primary plots were observed in diameter at breast height (dbh) and basal area growth in the UMF. AGB recovery in the LOF plots was significantly slower that in other plot types. After three decades, the UDF and the UMF plots had AGB values similar to those of their primary plots. This study indicated that selective logging practices need to be improved to enhance the sustainability of timber production. Long-term monitoring, along with the establishment of more plots and the measurement of additional tree-competition parameters, is needed to clarify outstanding uncertainties.

Coptotermes curvignathus is a subterranean termite species that vigorously feed on living-tree. The cellulose, hemicelluloses, lignin components in the wood are too robust for many organisms to break down and extract energy from but they serve as main carbon and energy sources for C. curvignathus. The ability of this subterranean termite thrive on wood diet may attribute by its array of laccase repertoire. Laccases are known for many functions including detoxification of plant tissues via xenobiotic pathway, and most importantly for termite is lignin modification. This paper highlighted the type of laccases produced by C. curvignathus based on transcriptomic data that were generated from 500 termites’ digestive system using Illumina HiSeq 2000. Raw data was trimmed and assembled by SOLEXAQA and Bowtie before loaded into Gene Ontology based data mining software, Blast2GO (B2G). The result showed that, C. curvignathus expressed diverse laccase genes that were phylogenetically similar to other termites’ laccases and distinctly related to fungal or bacterial laccases. Other than providing laccase genes sequences for further gene and enzyme characterization, the result of this study is the first insight into C. curvignathus laccase repertoire that is important to elucidate how C. curvignathus could digest wood efficiently from either intact or partially hydrolyzed wood.

Tirathaba mundella Walker is an important pest in many oil palm plantations especially those established on peatland. The life cycle of T. mundella has not been described in detail despite its economic importance. This study aimed to describe the bionomic characteristics of T. mundella, rearing on an artificial diet, at 25 oC. The duration of a complete metamorphosis cycle of T. mundella was about 51.63 ± 3.80 days. The incubation period was the shortest (3.33 ± 0.80 days.), The most detrimental stage of the pest to oil palm is at larval stage, which took 33.90 ± 2.60 days before pupating. The pupal period took about 5 to 11 days with a mean ± SD period of 8.53 ± 1.48 days. The average of the adult’s longevity was about 6.05 ± 1.81 days. There is no statistical difference between the duration of male and female longevity. Adult male and female moths reared in captivity feeded with 10% sucrose solution would mate readily and produce fertile eggs. The mean preoviposition period were 4 days. Successful of rearing T. mundella using artificial diet under laboratory conditions promises laboratory assessment for pesticide development which is less tedious and time consuming than conventional field experiments.

Forest restoration through enrichment planting may, in the long term, substantially enhance the soil productivity. The time for a forest to be restored depends on productivity of the tree species and treatments applied during the planting process. Throughout the forest restoration period, planted tree species growth may either positively or negatively affect the soil condition. Thus, it is essential to study the relationship between the changes in soil properties and growth rate of trees at different ontogenetic phases in a rehabilitated forest. Observation on D. beccarii showed tree height growth rate increasing rapidly at the early stage, followed by apparent bulking up in stem diameter in 9–year–old stand. The higher tree density in 14–year–old stand contributes to high LAI value. The expansion of canopy size was rapid in 20–year–old stand. Tree height showed sigmoid growth pattern, while growth rate of stem diameter, canopy size, and LAI were still constantly increasing up to 20 years. The soil pH level in all tree stands became less acidic while bulk density and soil moisture content were decreased as the tree age increased. Except for exchangeable Mg and Ca, significant reduction (P<0.05) in soil total N, available P, and exchangeable K were observed in the older stands. In 20 years, D. beccarii stand was able to reduce soil acidity as well as increase exchangeable Mg and Ca despite the loss of soil total N, available P, and exchangeable K.

Tree species composition and diversity were determined at 1,600 m Payeh Maga Highland in Lawas, Sarawak, Borneo. Five study plots (20 x 20 m) were established at five transect lines (1 ha). The study shows that the forest was represented by 40 families, 68 genera and 151 species. Fagaceae represented 26 % of the families recorded, followed by Myrtaceae (16 %) and Clusiaceae (12 %) which are a typical family of montane forest in this region. Important Value Index (IV) showed Lithocarpus urceolaris as the most important species (IV=294 %), followed by Gymnostoma sumatranum (IV=273 %) and Tristaniopsis microcarpa (IV=194 %). There are no significant differences among transects for number of species and diversity indices. This forest is important for biodiversity conservation as it is as rich as those reported for lowland forests elsewhere in this region. The continued accumulation of species is an indication that this highland could support and provide habitat for larger tree species communities.

Study on leaf properties of an endangered dipterocarp tree species, Dryobalanops beccarii, was conducted in a restored forest. The study focused on the morphology, nutrient concentration and gas exchange in well-developed leaves of D. beccarii at different ontogenetic phases. The hypothesis tested that leaf physiological and morphological changes are related to the nutrient concentration level of D. beccarii leaves in each ontogenetic phase. Seedling leaves were small and thin, whereas adult tree leaves were the large and thick. The stomata density per unit was abundant in adult tree leaves as compared to seedlings and saplings leaves. The net photosynthetic rate (Pn), transpiration rate (A) and stomatal conductance (gs) was increased from the seedling phase until the sapling phase, but decreased as the D. beccarii reached the mature phase. Scarce stomata density in seedling leaves contributed to low Pn, A and gs, while sapling leaves recorded opposite results due to abundant stomata density accompanied by highest accumulation of nitrogen (N) content per unit leaf area. The low concentration of nitrogen (N), phosphorus (P) and magnesium (Mg) detracted the gas exchange performance. Hence, changes in leaf morphology and physiology of D. beccarii were affected by the differences in resource used at each tree ontogenetic phase.

Bacteria and enzymes in the gut of termites play an important role to digest lignocellulosic material. Coptotermes curvignathus is one of the very few destructive species that can infest living plants. In this study, five bacteria isolated from C. curvignathus gut; four aerobic Bacillus spp. and an anaerobic uncultured bacterium were identified to produce endoglucanase with molecular size of 11 kDa which is significantly smaller than the endoglucanase produced by Reticulitermes speratus. Biolog reader identification showed that TG117 and N45/1 were Bacillus cereus/thuringiensis, TG111 was Bacillus pseudomycoides and TG005 was Bacillus mycoides. Endoglucanase produced by aerobic isolate NA45/1 showed promising potential as an industrial enzyme with significantly higher enzymtic activity than the commercial cellulase from Aspergillus Niger (C1184 Sigma). Endoglucanase NA45/1 displayed enzymatic activity 0.3961 U at pH 9 and 45°C. The endoglucanase TG111 acted optimally at alkaline condition with 0.2294 U whereas endoglucanase TG117 functioned best at slightly acidic condition. This study showed that the termite gut has a wide range of endoglucanase enzymes with various optimum temperatures and pH.

Land degradation and declining soil fertility challenge the productivity of forest plantations. Changes in soil properties could act as indicators for monitoring forest plantation management and productivity. This study highlights changes in soil properties and stand productivity over time (1, 3, and 5 years) in an Acacia mangium plantation in Bintulu, Sarawak, Malaysia. Soil pH, total N concentration, and available P were found to decline significantly with stand age. Significant differences were observed between soil organic C for different stand ages, with the youngest stand showing the highest C. The study showed that the current A. mangium plantation was able to store 74.9, 89.9, and 138.9 t C ha-1 in the 1-, 3-, and 5-year-old stands, respectively, and soil was the main contributor for the total C pools. All soil chemical attributes showed declining trends with stand age. These declines indicated that the present management practices are not sustainable and that management inputs are necessary.

Coptotermes curvignathus (C. curvignathus) are subterranean termites that feed on living-tree as their sole diet,which consist mainly of cellulose, hemicelluloses, lignin, plant allele chemical and other environmental residues such as insecticide. The xenobiotic compounds, plant allele chemical and insecticide are hazardous to termites health and need to be transported out of their body via xenobiotic and detoxification metabolism. This paper highlighted the potential enzymes that play vital role in the xenobiotic and detoxification metabolism. Transcriptomic data were generated from 200 termite’s digestive system using Illumina HiSeq 2000. Raw data was trimmed and assembled by SOLEXAQA and Bowtie before loaded into Gene Ontology based data mining software, Blast2GO (B2G). The result showed that, C. curvignathus contain enzymes that involved in all three biotransformation phases of xenobiotic and detoxification metabolism, which included cytochrome P450s monooxygenases, glutathione S-transferase, carboxylesterase, UDPglucuronyltransferases and N-acetyltransferase. The result of this study is the first insight into Cc xenobiotic pathway.

Coptotermes curvignathus Holmgren is capable of feeding on living trees. This ability is attributed to their effective digestive system that is furnished by the termite's own cellulolytic enzymes and cooperative enzymes produced by their gut microbes. In this study, the identity of an array of diverse microbes residing in the gut of C. curvignathus was revealed by sequencing the near-full-length 16S rRNA genes. A total of 154 bacterial phylotypes were found. The Bacteroidetes was the most abundant phylum and accounted for about 65% of the gut microbial profile. This is followed by Firmicutes, Actinobacteria, Spirochetes, Proteobacteria, TM7, Deferribacteres, Planctomycetes, Verrucomicrobia, and Termite Group 1. Based on the phylogenetic study, this symbiosis can be a result of long coevolution of gut enterotypes with the phylogenic distribution, strong selection pressure in the gut, and other speculative pressures that determine bacterial biome to follow. The phylogenetic distribution of cloned rRNA genes in the bacterial domain that was considerably different from other termite reflects the strong selection pressures in the gut where a proportional composition of gut microbiome of C. curvignathus has established. The selection pressures could be linked to the unique diet preference of C. curvignathus that profoundly feeds on living trees. The delicate gut microbiome composition may provide available nutrients to the host as well as potential protection against opportunistic pathogen.

Secondary forest is a forest regenerates in through natural processing after human disturbance. Objective of this study was to investigate growth rate of tree species in a secondary forest. This study was carried out in 10 established plots of 50 × 20 m at Nurwana Forest, a 16-year-old logged-over forest in Universiti Putra Malaysia Bintulu Sarawak Campus. In this study, tree species with 10 cm diameter breast height and above were selected. Majority of tree (78%) were found in smaller diameter class with only 0.8% having diameter more than 55 cm. The diameter growth rate in Nirwana Forest was better as compared to other reported results either in primary forest or secondary forest.

Th eeff ect of soil chemical properties on the diversity and colonization of arbuscular mycorrhiza (AM) varies among ecosystems. This study was conducted to assess and compare the abundance of AM in a rehabilitated forest and a logged-over forest soil using the most probable number and spore number methods. Glomus (71.7%-82.1%) and Acaulospora (17.4%-19.5%) were found to be abundant in both sites, while Gigaspora was found only in the loggedover forest. Th e abundance of AM in the rehabilitated forest based on the spore count was signifi cantly higher than in the logged-over forest by a 6-fold diff erence. Furthermore, root colonization in the rehabilitated forest was found to be almost 9-fold higher than in the logged-over forest. Such diff erences are linked to the soil chemical properties. The addition of organic matter during forest rehabilitation activity had created favorable conditions for AM sporulation. Soil P in both forests was positively related to the spore count (r > 0.68, P < 0.001) while the most probable number (MPN)was negatively infl uenced by soil K (r = –0.632, P <0.01). In conclusion, this study showed that soil chemical properties have a direct eff ect on the abundance of AM.

Tropical forests are fast disappearing. Available forested areas al-e inostly in degraded condition that may not be suitable for dipterocarp species to grow. Reforestation could bring back these forests. The objectives of this study were to determine the diameter growth rate and photosynthetic rate of 17-year-old Shorea pa~vlfolia and Shorea mecistopteryx established in a rehabilitated project. Although both species have similar leaf area index, diameter growth rate of S. rnecisfopferyx is higher as compared to 5'. pawijblia. Shovea mecistopteryx recorded significantly higher photosynthesis rate than S pawijblia. Pearson's Correlation Coefficient confirmed that growth rate was influenced by photosynthetic rate.

Banana (Musa spp.) is an important nutrient-rich fruit crop cultivated in the tropics and sub-tropics for local consumption and export. Targets for genetic improvement of banana range from improved fruit quality, yield, disease resistance, tolerance to biotic and abiotic stresses, and the biosynthesis of pharmaceutical compounds. Sterility has limited the success of generating new cultivars by conventional breeding. Tissue culture-based technologies that involve embryo rescue, the generation of somaclonal variation, and gene-transfer procedures are a useful adjunct to sexual hybridization, although considerable effort is required to establish robust protoplast-to-plant systems for somatic hybridization. Transformation involving Agrobacterium and biolistics- mediated gene transfer is feasible, underpinned by shoot regeneration from cultured cells and tissues. Molecular characterization of germplasm will facilitate the selection of material most relevant for incorporation into sexual and somatic genetic-improvement programs.

In Malaysia, forester roles are changing, shifting towards social and environmental conservation from traditional forestry. In order to meet such changes, emphasis are made on personal, social, interdisciplinary and problem-solving skills to help forester in dealing with human aspects of forestry and managing as well as applying multidisciplinary and participatory approaches. This paper highlights on the latest approach by Universiti Putra Malaysia in reviewing and developing a new curricula for its Diploma in Forestry Program. It traces the development of diploma program in Malaysia, its past and future direction. Discussion on changing requirements in the forestry profession especially semi-professional forester will also be discussed.

Octomeles sumatrana and Anthocephalus chinensis are two non-commercial tree species with future potential as plantation species in Malaysia. In order to understand the habitat in which such species grow, a study on the species as well as organisms related to them is crucial. The objectives of this study were to investigate the soil properties in which the two species grow and the associated mycorrhiza occurring within their rhizospheres. Results revealed that the properties of rhizosphere soils and the composition of arbuscular mycorrhiza varied with location. Based on the spore count method, the mean number of spores ranged from 45–142 per 50 g dry soil. The rhizosphere of O. sumatrana at the Niah Forestry Research Station recorded the highest number of spores. Meanwhile, the most probable number method showed values ranging from 6.5–16.0 per gram of dry soil, with the highest value recorded for O. sumatrana at the Niah National Park. A. chinensis showed the lowest values for both methods. Glomus was found to be dominant in the rhizospheres of both species followed by Acaulospora and Gigaspora. O. sumatrana was found to be a better host plant than A. chinensis in terms of supporting the sporulation of mycorrhiza. This is believed to be closely related to the ability of the root system to make the rhizosphere more suitable for reproduction and development of mycorrhiza spores, besides being affected by soil properties.

Azadirachta excelsa or sentang is one of the important tree species grown in Malaysia. Equations for the predicting stem volume, from the ground to the tip for this species, are not available and hence this paper attempts to apply and examine the suitability of the existing volume equations for the species which can be used by plantation growers in Malaysia. Furthermore, the performances of available volume equations in Malaysia are seldom investigated. Evaluation is important to determine the usefulness and increase the confidence of using a model. Three commonly used models were compared using the data derived from 36 harvested trees to fit the equations. The addition of the weight function of 1/(d2h) was used to fit the Spurr’s combined variable volume equation. Then, the performances of the models were evaluated based on R2, PRESS, bias and RMSE values. The Schumacher and Hall’s equation was found to be the most appropriate for determining the total and merchantable underbark stem volume of A. excelsa, whereas the Spurr’s equation was indicated as more suitable to determine the merchantable overbark volume.

Arbuscular mycorrhiza fungi are soil fungi that form mutualistic symbiosis with the roots of plant. The objectives of this study were to investigate the diversity of arbuscular mycorrhiza and to identify isolated spores associated with Calophyllum sp. This study was carried out in a replanted forest and a logged-over forest in Universiti Putra Malaysia Bintulu Campus (UPMBC). Samples of top soils that coexist with the selected host plant, Calophyllum sp. were collected. Total abundance of spores, species richness (S), Shannon-wiener Diversity Index (H’) and evenness (EH) were calculated. A total of 13 species of arbuscular mycorrhiza were isolated where 10 species were identified at the genus level. The replanted forest showed higher arbuscular mycorrhiza spores diversity as compared to the logged-over forest. On the other hand, the logged-over forest recorded higher evenness value as compared to the replanted forest. This was probably due to the fact that the replanted forest had the highest number of the Glomus species spores when compared to other genera. The present study suggested that proper logging practices have to be imposed in order to enhance the abundances and activities of AM fungi. The impact of harvesting on soil or site must be taken into consideration especially in maintaining soil productivity. The present study also proposed that the number of spores in the soil might act as one of the indicator to detect the level of disturbances in the forest.