Category Archives: 2014 Vol 26 June

The Palm Kernel Oil Ester Nanoemulsion System using Pluronic F-127 as a Polymeric Surfactant via a High Energy Emulsification Method

The study of formation of nanoemulsions by low energy emulsification method was carried out in water/surfactant/oil system. Palm kernel oil ester (PKOE) was used as the oil phase while Pluronic F-127 was chosen as the surfactant. A ternary phase diagram was constructed for the water/Pluronic F-127/PKOE system by changing the composition concentration at constant temperature. The pre-emulsions were prepared based on the constructed phase diagram via a low energy emulsification and these were characterised with respect to centrifugation force and particle size. Since the particle size formed was large, they were then subjected to high energy emulsification to reduce the particle to nano-size. Formulations with particle size from 93- 127 nm were successfully formed. Kinetic stability was assessed by measuring particle size as a function of time and storage condition. Droplet size of the formulations did not show any significant changes with 135 nm after three months. The morphology study was carried out on two formulations using low energy and high energy emulsification. Formulation using high energy emulsification showed an image with smaller and well distributed droplets compared to low energy emulsification.

Field Evaluation of Harvesting Machines for Tall Oil Palms

Harvesting is a very important activity in any agriculture business. Cheap and efficient harvesting processes are factors that ensure good returns. Efficient mechanical harvesting of oil palm fresh fruit bunch (FFB) remains an issue that needs to be addressed. The current methods of harvesting involve the use of a chisel or sickle, which require manual labour and is therefore tedious. As the country is facing a labour shortage in the plantation sector, the introduction of farm machinery would be one way of increasing labour productivity. This article describes the performance of two oil palm mechanical harvesting machines in the field as compared to a manual operation. The machines carried out cutting operations of the FFB, which were transported to the road side and unloaded either onto the mainline transport or to the ground. A time motion study during the cutting operation was carried out, and the quantity of detached loose fruits produced were recorded. Machine performance in terms of productivity and cost-effectiveness were also monitored. It was found that the productivity of the machines ranged from 3 to 6 t per day depending on various factors. This study also indicated that the loose fruits collection could be minimised by using the harvesting machine. A comparative study of the harvesting machines with and without grapple shows that the latter is slower, even though it is only used for cutting operation, without deposition of the bunches into the bucket. The productivity (man per day) of the complete harvesting machine was almost double, compared to manual harvesting that uses buffalo-carts for the evacuation of the FFB. However, the economic analysis shows that the cost per tonne for mechanical harvesting machine was slightly higher as compared to manual operation. It is envisaged that with the successful introduction of the mechanical harvester, opportunities for new technologies would open up for the development of more efficient and cheaper machines in the future.

The Use of Palm Kernel Cake in the Production of Conidia and Blastospores of Metarhizium anisopliae var. major for Control of Oryctes rhinoceros

The yield of conidia and blastospores of Metarhizium anisopliae var. major produced on maize supplemented with palm kernel cake (PKC) was estimated. In maize supplemented with 5 g and 10 g of PKC, the fungus produced 4.3 g and 5.6 g of conidia respectively. This is significantly higher than the yield of conidia produced on maize alone, which was 2.03 g. The fungus produced submerged spores termed as blastospores, in a simple liquid medium consisting of glucose and PKC. The formation of blastospores during the fermentation process was monitored. The results showed that the young blastospores are round to ovoid, with 5.0-5.5 μm in diameter and matured blastospores are commonly ellipsoid with dimensions ranging from 5.0-5.5 μm x 12.5-15.5 μm. The highest yield of the blastospores was 3.26 x 106 blastospores ml-1, produced at seven days after fermentation. The conidia and blastospores were equally effective in controlling the third instar larvae of the Oryctes rhinoceros. Sixteen days after treatment, both inocula killed 100% larvae, with infection of between 94.3% and 97.1%. The LC50 values for both inocula were almost similar, at 9.1 days for conidia and 9.5 days for blastospores. This study showed that PKC can be used as a supplement to produce conidia and blastospores of the fungus, M. anisopliae var. major, and that the blastospores are potential for the biocontrol of the rhinoceros beetle.

Population Dynamics of Oryctes rhinoceros in Decomposing Oil Palm Trunks in Areas Practising Zero Burning and Partial Burning

Zero burning concepts during oil palm – to – oil palm replanting has provided ample breeding and foraging sites for the Oryctes rhinoceros beetles. This study investigated the impact of the different techniques of residue management in oil palm replanting to the abundance of O. rhinoceros. Two types of breeding sites, zero and partial burning were selected and the beetle populations were determined between three to 18 months after felling and chipping (MAF). At the sixth MAF, different stages of O. rhinoceros were collected from chipped trunks. The results showed that a high population of O. rhinoceros was detected at the 13th MAF; no beetles were detected at the third, fourth and fifth MAF from both types of breeding sites. The third instar larvae were recorded as the dominant stage detected during the study. The females were found to be more abundant than the males, indicating better food quality and a potential for higher infestation for the coming months. There was no significant differences on the population of O. rhinoceros in both sites. The beetles population tended to increase with MAF. The results of this study suggested that the partial burning of chipped trunks did not decrease the population of O. rhinoceros apart from polluting the environment.

Rachis Nutrient Concentrations of Different Oil Palm Genotypes as Affected by Irrigation and Terrain

Four clonal oil palm materials namely AVROS, Yangambi, La Me and NIFOR, and two D×P hybrid Yangambi have been planted on terraced and non-terraced contours that are subjected to irrigated and nonirrigated conditions. Under favourable growing environment, i.e., through irrigation, and to some extent favourable terrain of undulating plain, the palms were able to retain higher rachis nutrient concentrations, and subsequently had larger petiole cross-section and exhibited higher rachis nutrient contents. There were significant differences in all rachis nutrient concentrations for all of the planting materials for both terrain and irrigation conditions except for sulphur (S) nutrient. Previous study revealed that leaf potassium (K) concentration for D×P hybrid Yangambi-DQ8 was consistently lower than AVROS-A122 by almost 15%-20% in all the growing conditions. In contrast, the rachis nutrient concentrations for both materials were comparable. In fact, D×P Yangambi-DQ8, retained higher rachis K content (by 22%) due to larger petiole cross-section (PCS) as compared to that of AVROS-A122. The poor yielding materials, appeared to contain lower nutrient concentrations particularly those of magnesium (Mg), chlorine (Cl) and calcium (Ca). The present fertiliser regime is able to sustain high yields and capable of producing more than 10.5 t ha-1 yr-1 of total economic product (TEP) without the need for additional fertiliser inputs. Therefore, the understanding of rachis nutrient behaviour on different oil palm genotypes is crucial to produce sustainable oil yield in the near future.

The Use of Mannose Selection System for Gene Transfer in Tobacco Plants (Nicotiana tabacum L.), A Model Plant for Oil Palm Transformation

A mannose selection system was evaluated for its potential application as a selectable marker in tobacco using biolistic transformation. The above system uses pmi gene isolated from Escherichia coli that helps transgenic plants expressing it to convert mannose-6-phosphate (from mannose) into a metabolisable carbon source, fructose-6-phosphate. The ability to utilise mannose allows the transformed cells to survive on the medium containing mannose as compared to the untransformed cells. This was achieved by transforming the tobacco leaf discs using a construct carrying the pmi and β-glucuronidase (gusA) genes which were driven by 35S cauliflower mosaic virus (CaMV35S) promoter. The tobacco leaf discs were cultured on medium supplemented with 30 g litre-1 mannose for callus induction, proliferation and regeneration. The presence of the pmi gene was proven by PCR analysis and β-glucuronidase (gusA) activity confirmed the expression of gusA gene. Results showed that this procedure might be efficient in tobacco and other plants. The transformation procedure presented here, PMI/mannose system for selection of transgenic plants, represents an alternative for the production of transgenic plants under conditions that are safe for human health and the environment.

Mechanical and Physical Properties of Oil Palm Trunk Core Particleboard Bonded with Different UF Resins

Rapid price increases and reduction in the supply of rubberwood has forced the particleboard manufacturers to look for new alternative raw materials. The production of particleboard from other wood species will be a good solution to the problem of depleting wood supplies. The objective of this study was to evaluate the properties of particleboard made from rubberwood and oil palm trunk pressed at different temperatures and times compared to particleboards made from single species. Two types of UF resins (E1 resin and SE0 resin) were applied in this study. The effect of surface-to-core ratio was also examined in this study. The modulus of rupture, internal bond strength and thickness swelling of the boards were evaluated based on the Japanese Industrial Standard for particleboard (JIS A 5908:2003). After evaluation, the panels produced are a potential substitute to the panels made from pure rubberwood.

Isolation and Selection of Reference Genes for Ganoderma boninense Gene Expression Study using Quantitative Real-time PCR (qPCR)

Quantitative real-time PCR (qPCR) has become a favourite method for quantification of mRNA transcripts. However, several optimisation steps must be performed to avoid misleading qPCR results. One of the steps is selection of reference genes for normalisation purpose and these genes should be stably expressed across the samples. In this study, isolation of partial-length cDNA encoding seven potential reference genes from Ganoderma boninense has been performed. These potential reference genes are α-tubulin, β-tubulin, β-actin, elongation factor 2 (eef2), glyceraldehyde 3-phosphate dehydrogenase (gapdh), 40S ribosomal (r40s) and ubiquitin C (ubc). The expression of these reference genes was studied in mycelia, white button and fruiting body tissues of G. boninense. The qPCR data were analysed using BestKeeper and geNorm algorithms and both softwares have identified β-tubulin, eEF2 and α-tubulin as the most stable reference genes and r40s and ubc as the least stable reference genes. Three reference genes with the lowest M value (eEF2, β-tubulin and α-tubulin) were recommended by the geNorm software to be used in the qPCR analysis for more accurate normalisation.

Threat from Fusarium Wilt Disease of Oil Palm to South-east Asia and Suggested Control Measures – Review Article

Fusarium wilt of oil palm caused by Fusarium oxysporum f. sp elaeidis (Foe) has in the past rendered oil palm production uneconomic in some regions of Central and West Africa, where it is endemic. It is an anomaly that the disease has not appeared in South-east Asia, where the palm lines used are susceptible to African Foe isolates and the climate should be conducive. Various evidence and speculation are offered here to explain the absence of the disease so far. Foe is a soil-borne fungus that infects intact roots, traverses the cortex to the stele to invade the xylem and systemically colonise entire palms. Yield loss and even death result from induced water stress and hormonal imbalance. Disease spread is localised and typical of a soil-borne pathogen. Breeding for resistance over several decades has markedly reduced losses and disease incidence, even though expression of resistance appears to be partial. Resistance is proving durable, probably because Foe is monophyletic and resistance is based on multiple genes. Contamination of seed and pollen by Foe, has implications for importation of oil palm breeding material from the African centre of diversity. Isolated outbreaks in South America were linked to inter-continental seed movement. Quarantine has long been enforced for imported seed and pollen imported to Malaysia. This laboratory devised a method of fungicide infiltration for eradication of Foe from seed and the method is used by some seed companies to their market advantage, and in intermediate quarantine on exported seed batches. Specific DNA, PCR-based probes for rapid detection of the oil palm pathotype has long been required to distinguish Foe from the commonly present species F. oxysporum; advanced progress based on a unique Foe virulence gene is described. This article will consider the biology, spread, impact, detection and control of this aggressive pathogen in order to enhance or maintain awareness of the disease in this region and maintain the status quo of plantations remaining free from Fusarium wilt.