Category Archives: 2020 Vol 32 Sept

THE EFFECT OF PLANT VOLATILES ON PLANT PREFERENCE BY THE PREDATORY INSECT, Sycanus dichotomus STAL. (Hemiptera: Reduviidae) IN OIL PALM PLANTATION

A study of choice test and no-choice test was conducted to test plant volatiles response to adult orientation behaviour and performance of predatory insect, Sycanus dichotomus on three beneficial plants (Turnera subulata, Antigonon leptopus and Cassia cobanensis) and three ground vegetation covers (Asystasia gangetica, Euphorbia heterophylla and Ageratum conyzoides). Gas chromatography-mass spectrometry (GC-MS) was used to determine the number of volatile compounds in the beneficial plants extracts, namely Trimethyl-3,4-methylenedioxychromane, Phenol,4,6-di(1,1-dimethylethyl)-2-methyl, 2H-1-Benzopyran,6,7-dimethoxy-2,2-dimethyl-, n-Hexadecanoic acid, Dodecanoic acid, 3-hydroxy-, Octadecanoic acid, and 2-(2-hydroxyethoxy) ethyl ester and to confirm the most preferred plant by the predatory insect. We recommend further investigation on the efficiency of various beneficial plants in relation to the activities of S. dichotomus.

MPOB OIL PALM (Elaeis guineensis Jacq.) GERMPLASMS LINKED TO COMPACT TRAIT FOR HIGH DENSITY PLANTING

The compact trait in oil palm was evaluated amongst the 11 germplasms collected from Nigeria, Cameroon, Zaire (now known as the Democratic Republic of Congo), Tanzania, Madagascar, Angola, Senegal, Gambia, Sierra Leone, Guinea and Ghana. The evaluation was based on the shortness of the rachis and a low height increment (HTi). However, priority was given to selection for short rachis length (RL). The MPOB-Madagascar germplasm showed the shortest RL and was significantly different from other germplasms for dura (RL = 3.22 m, HTi = 0.21 m yr-1). As for tenera, the shortest RL was found in MPOB-Tanzania germplasm (RL = 4.44 m, HTi = 0.19 m yr-1) but not significantly different from MPOBGuinea (RL = 4.49 m, HTi = 0.39 m yr-1). The coefficient of variation (CV) for both dura and tenera accessions were considerably low with most germplasm showing CV of less than 20%. The highest RL CV among duras was noted in MPOB-Madagascar germplasm (CV = 18.09%), while among teneras, high variation was observed in MPOB-Guinea germplasm (CV = 13.72%). Broad-sense heritability estimate of RL for MPOB-Madagascar was highest for dura (h2B = 100%) while that for MPOB-Zaire was highest for tenera (h2B = 100%). Phenotypic correlations were moderately positive between RL and HTi for most germplasms providing the possibility of developing compact palms suitable for higher density planting which consequently would result in increased oil palm yield per hectare. In summary, MPOB-Tanzania germplasm showed good potential for further introgression into advanced breeding populations for the generation of future compact planting materials

DETRIMENTAL EFFECTS OF COMMONLY USED INSECTICIDES IN OIL PALM TO POLLINATING WEEVIL, Elaeidobius kamerunicus FAUST. (Coleoptera: Curculionidae)

Elaeidobius kamerunicus is the main insect pollinator of oil palm in Malaysia. It has improved oil palm pollination, thus leading to a better yield. The lethal concentrations (LC50) of four currently used oil palm commercial insecticides, namely cypermethrin, trichlorfon, fipronil and Bacillus thuringiensis on E. kamerunicus were determined using residual film, topical spray and oral bioassays. The weevil mortality was recorded at 24, 48 and 72 hr after treatment. Probit analysis was used to determine LC50. The result showed that male weevils were more susceptible to trichlorfon and fipronil than female weevils. However, there was no difference between sexes in terms of susceptibility towards cypermethrin. Among the tested insecticides, fipronil had higher lethality on weevil whereas B. thuringiensis was less harmful to weevil mortality by <20% even when treated at the highest concentration (0.26% product). Regardless of the type of insecticides and exposure time, the weevil was less sensitive to the insecticide applied via spray method as compared to oral and residual film. The study findings provide useful information in determining the less harmful insecticides to this pollinating weevils with various mode of actions.

QUANTIFYING SPATIAL VARIABILITY OF SOIL AND LEAF NITROGEN, PHOSPHOROUS AND POTASSIUM OF BASAL STEM ROT INFECTED OIL PALMS USING GEOSPATIAL INFORMATION SYSTEM

Basal stem rot disease (BSR) is known to be responsible for yield losses in oil palm plantations in Southeast Asia. A balance nutrient in soil and leaf is known to improve the plant health and disease resistance. In order to observe how nitrogen (N), potassium (P) and phosphorus (K) content in soil and leaf affect the BSR occurrence, a field study was conducted in infected blocks of oil palms at two different ages. Nutrients variability (N, P and K) were obtained, analysed and mapped using classical statistics and geospatial method. Correlated to BSR disease, total N and available P in soil were found to be high in both blocks. However, exchangeable K exhibited low level. Total N and available P in soil of Blocks 1 and 2, and N and P in leaves of Block 1 showed a significant association with the disease (p<0.01). The generated variability map and significant correlations revealed that imbalanced nutrient content occurred in the study area. This would be one of the causes that lead to the disease outbreak.

REVERSE TRANSCRIPTION LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (RT-LAMP) FOR DETECTION OF COCONUT CADANG-CADANG VIROID (CCCVd) VARIANTS IN OIL PALM

The coconut cadang-cadang viroid (CCCVd) is the causal agent of orange spotting (OS) disease in commercial oil palm (Elaeis guineensis) plantations in Malaysia. At present, the methods used to detect OS are time-consuming and can be inaccurate. Here, we describe the development of a rapid, sensitive and specific method of detecting CCCVd variants in oil palm leaves using a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. RT-LAMP detected CCCVd variants at a concentration of 2 ng μl-1 in less than 1 hr at 63°C using total ribonucleic acid (RNA) of leaf extracts; whereas a minimum of 20 ng μl-1 was required to detect CCCVd using conventional polymerase chain reaction (PCR). The utility of RT-LAMP as OS detection in plantations was evaluated using symptomatic and asymptomatic oil palm leaf samples from nurseries and field sites. RT-LAMP successfully detected CCCVd in OS-infected samples. Leaves with OS-like symptoms caused by nutrient deficiencies or leaf spot disease other than OS produced a negative result. The RT-LAMP results were confirmed by conventional PCR, indicating that RT-LAMP is a valuable tool, sensitive and rapid method of diagnosing OS in oil palm plantations that could be performed by plantation personnel for OS disease management in oil palm plantations.

PRODUCTION AND PROPERTIES OF SOLID BIOCHAR FROM OIL PALM TRUNK WASTE USING SUB-CRITICAL WATER TECHNOLOGY

Sub-critical water (sub-CW) technology was utilised to produce solid biochar (SB) from oil palm trunk (OPT). This study evaluated the production of SB from sub-CW treatment of the top and bottom parts of 21- and 35-year old OPT. The SB production and its properties were assessed by means of higher heating values, elemental analysis, scanning electron microscopy, and particle size distribution. Treatment of the OPT21T at 300°C for 5 min produced a high yield of SB at 0.18 kg kg-dry OPT-1. The highest higher heating value (HHV) of SB was 32.4 MJ kg-1 from the treatment of OPT21B at 340°C for 5 min. The SB had higher HHV than petroleum coke but was within the range of general-purpose coal. Elemental analysis of SB revealed the occurrence of carbonisation and the extent of pyrolysis reaction judging from increasing the carbon value of SB with increasing temperature. The particle size distribution of SB at 370°C and 5 min reaction time was in the range between 8 and 10 μm. Consequently, sub-CW is a promising technology to convert waste oil palm trunks into micro-particle SB with high HHV for possible use as alternative fuel and for improving soil productivity.

OCCURRENCE, DISTRIBUTION AND FARMERS’ KNOWLEDGE ON THE MANAGEMENT OF Fusarium WILT OF OIL PALM AMONG SMALLHOLDERS IN KALANGALA, UGANDA

Fusarium wilt of oil palm is caused by Fusarium oxysporum f. sp. elaeidis and is particularly prevalent in Africa. This study was conducted in Kalangala district, the commercial oil palm cradleland in Uganda and it involved undertaking a survey among smallholder farmers to assess the occurrence, distribution, farmers’ knowledge and management level of Fusarium wilt of oil palm. This was achieved by taking an inventory of all the plants in a given plot, noting the presence or absence of symptoms of Fusarium wilt and calculating the incidence in each given plot. This is the first time Fusarium is identified in oil palm plantations in Uganda and the results showed that infected trees were mainly found in Mugoye sub-county, Kagulube block. The highest average severity (3) was observed in Kagulube as compared to all other blocks (severity score 2). The highest percentage incidence (15%) was noted in Kagulube and the least (5%) in Bbeta East, Bbeta West and Bujjumba blocks. Despite the widespread occurrence of Fusarium wilt in Kalangala, management of the disease among farmers was inadequate. Urgent measures need to be undertaken to prevent spread of Fusarium wilt within and among farmers’ fields.

BACTERIAL DIVERSITY IN LOGGED OVER FOREST OF MINERAL SOIL BEFORE DEVELOPMENT OF OIL PALM PLANTATION IN BELAGA, SARAWAK

Tropical forests are major reservoirs of biodiversity. Soil microbes play important roles in soil fertility. Microbes are sensitive to changes in agricultural activities occurring in the soil, thus they can be used as an indicator for soil quality. This study was conducted to analyse soil microbial biodiversity at logged over forest on mineral soil before development to oil palm plantation, by using denaturing gradient gel electrophoresis combined with 16S rDNA polymerase chain reaction (PCR-DGGE). The average number of bands from PCR-DGGE profiles indicated strip 2 was significantly less diversified than the rest of the sites at α=0.05. Shannon-Weaver biodiversity index and Berger-Parker Dominance Index, showed highest diversity in area cultivable for oil palm, followed by the biodiversity strip areas. Bacterial communities were dominated by unclassified bacteria, Acidobacteria, Actinobacteria and α-Proteobacteria groups in all types of forest soils. Acidobacteria group was absent in strip 3 where the soil pH was least acidic. Common species found for all sites were, uncultured Acidobacteria bacterium (Acidobacteria), uncultured Actinobacterium clones (Actinobacteria) and uncultured Rhodoplanes sp. (α-Proteobacteria).

OIL PALM ETHYLENE RECEPTOR GENE FAMILY: IDENTIFICATION, CHARACTERISATION AND EXPRESSION ANALYSIS

The ethylene receptor family is the first component of the ethylene signaling pathway to trigger the plant’s response towards ethylene and consequently affect plant growth and developmental processes. In oil palm (Elaeis guineensis Jacq.), an ethylene receptor gene has been isolated and characterised. However, the full information about the gene family is unavailable. Thus, in this study, we focused on the identification, isolation and characterisation of the ethylene receptor gene family from oil palm. A total of seven genes were identified, isolated and characterised using a combination of in silico bioinformatics tools and experimental insights. Structural comparison and phylogenetic analyses showed the genes are classified into two subfamilies. Subfamily I consists of three members whereas subfamily II has four members. Expression analyses of the ethylene receptors in various oil palm tissues suggested multiple roles of the ethylene receptors in regulating many processes in oil palm growth and development such as fruit growth, ripening and abscission and flower development. Therefore, all together, these results will be beneficial to further investigate the functions of ethylene and the potential use of the genes to manipulate ethylene responses in oil palm for yield improvement.

ECONOMIC FEASIBILITY OF CLONAL OIL PALM PLANTING MATERIAL

Tissue culture-derived planting materials have been proven to outperform the standard dura x pisifera (DxP) materials, in which most clones have reportedly surpassed the standard DxP performance by at least 20% on average in terms of fresh fruit bunch (FFB) yield on a per hectare basis. This advantage seems to benefit the industry players as higher productivity will lead to higher income. However, the cost of producing clonal materials is considered as one of the major bottle-necks in the large scale usage of clonal planting materials in the oil palm industry. This article aims to evaluate the economic feasibility of clonal oil palm planting materials using a cost-benefit analysis. Among the financial parameters used to measure the feasibility are namely the Net Present Value (NPV), Internal Rate of Return (IRR) and payback period. Based on these parameters, the study suggests that the clonal planting material is a viable venture and worth the investment as it provides better yield, both in terms of FFB and oil yield, which translates into better returns for the industry players despite the premium price of clonal materials as compared to that of the seedderived standard DxP.

ASSESSMENT ON VORACITY AND PREDATION BY PREDATOR, Sycanus dichotomus STAL. (Hemiptera: Reduviidae) TO OIL PALM BAGWORM, Pteroma pendula

Sycanus dichotomus Stal. (Hemiptera: Reduviidae) is a generalist predator with a wide prey spectrum that commonly preys on bagworms and nettle caterpillars in oil palm plantations in Malaysia. The voracity of fifth instar nymphs and adults (males and females) of S. dichotomus using Pteroma pendula Joannis (Lepidoptera: Psychidae) third instar larvae as prey was evaluated in the laboratory, as well as its relationship with the development stage and exposure time on the voracity and predation rate. The number of preys consumed by predators was recorded at every 3, 24 and 48 hr intervals. The maximum voracity and predation rates were always greater in adults. The adult females displayed the highest prey consumption (1.0- 4.33 bagworms) followed by adult males (0.67-4.17 bagworms), and fifth instar nymphs (0.5-3.0 bagworms) at all time intervals. Although the fifth instar nymphs were able to kill the prey offered, the differences in predation potential indicated that the adult males and females were more vigorous and voracious in capturing and killing prey compared to the fifth instar nymphs. Results showed that the overall effect of the developmental stages of S. dichotomus on voracity and predation rate was highly significant (F = 10.420; df = 2; P <0.001). Similarly, the time intervals also exhibited a highly significant effect on the voracity and predation rate of S. dichotomus (F = 95.267; df = 2; P <0.001). However, the relationship between the predator developmental stages and exposure times was not significant (F = 2.444; df = 4; P = 0.300). This finding indicates the potential of the adults’ stage of S. dichotomus to be released in the field, aiming for greater bagworm reduction in subsequent generation. In future research, it is necessary to assess the dynamic features of preypredator system in an actual oil palm field.

SUSTAINABILITY OF PALM OIL AND ITS ACCEPTANCE IN THE EU – Review Article

Palm oil is highly controversial within the European Union (EU) as is illustrated by regular items in public media and decisions by the European institutions, such as the European Parliament. Producing countries are hardly engaging in these public and political debates but their participation is essential to develop an effective sustainable palm oil strategy. This article reviews the recent and current debates within the EU on palm oil use for biofuels and for food and other purposes. It proves important to distinguish between these two different goals because their governance dynamics within the EU are completely different. The biofuels market is dominated by government institutions while the market for food and industrial goods is dominated by private companies and private governance initiatives. Engagement of producing countries is likely to have little impact on the EU’s biofuels policy. More opportunities exist in the market for food and other purposes, provided attention is being paid to legitimacy and accountability of producing countries’ engagement.

OXIDATIVE STABILITY AND PHYSICOCHEMICAL PROPERTIES OF PALM OLEIN

Oxidised oil has been emerged as a root for many chronic diseases. The study was aimed to evaluate the effects of heating on oxidative stability and physicochemical properties of palm olein. Palm olein was heated to 80°C (P80) and 120°C (P120) up to 12 hr. The positional distribution of fatty acids, fatty acid composition (FAC) and iodine value (IV) were analysed using proton-Nuclear Magnetic Resonance (1H-NMR) and carbon- Nuclear Magnetic Resonance (13C-NMR). The slip melting point (SMP), peroxide value (PV), cloud point (CP) and free fatty acid (FFA) contents of the oil were determined according to MPOB Test Methods. Results implied that the regiospecificity of fatty acids in palm olein, FAC, IV and SMP remained unchanged (p>0.05) after both heating treatments for 12 hr. The FFA of P80 and P120 were gradually increased, even so, their FFA were within the acceptance level under prolonged heating for ≤ 10 hr. The CP of P80 and P120 were gradually increased due to an increase in the amount of FFA in the oils. In general, palm olein exhibited good oxidative stability after being heated for up to 2 hr at 80°C and 120°C beyond which the oil deteriorated. Overall, this study revealed that palm olein – as a cooking oil – was thermally and oxidatively stable under normal cooking environment.

DEVELOPMENT OF NEW OIL PALM CULTIVARS IN MALAYSIA

At the beginning of the oil palm industry at the turn of the 20th century, commercial plantations utilised the thick-shell thin-mesocarp dura planting materials. The breeds were unconsciously and informally selected from the ‘best-looking’ palms and fruits in the African palm groves or in subsequent decorative avenues elsewhere. Discovery of the single gene inheritance for shell thickness led to the use of the thinner- shell thicker oil-bearing mesocarp dura x pisifera (DxP) cultivated variety (cultivar). However, oil palm breeding populations had been derived from few ancestral palms, which hindered selection progress. The basic population of the maternal line in breeding programmes is almost exclusively the Deli dura. Improvements of tenera/pisifera paternal lines were mainly the AVROS, La Me and Yangambi populations. Malaysian oil palm breeders widely practiced the modified recurrent selection (MRS) in improvement programmes. Subsequent parental inbred lines developed in recurrent selections, crossed and progeny tested exploiting heterosis had boosted bunch and oil yields. The MRS allows incorporation of new genes into the parental lines; and coupled with the need to widen the genetic pool, wild Elaeis guineensis and E. oleifera germplasms were prospected in centres of origin and diversity in Africa and Latin America, respectively. Besides breeding for bunch and oil yields, secondary traits such as dwarfism, oil quality and phytonutrient contents are incorporated in developing PS series new varieties for niche purposes. A notable cultivar is PS1 characterised by short palm height. It takes more than 20 years from collection in the wild to the release of new cultivar. To speed up selection and release of cultivar, the preliminarily selected breeding materials are shared among local industry breeders for further breeding and improvements. In addition to quantitative genetics, further strides in cultivar development are supported by tissue culture, biotechnology and genomics. New varieties are registered based on the Test Guidelines for new, distinct, uniform and stable (DUS) of the International Union for the Protection of New Varieties of Plants (UPOV). Commercial production and sale of oil palm planting materials in Malaysia are regulated by law. Oil palm seed producers must be a registered company, financially sound and has a competent breeder. Seeds and seedlings for commercial sale must fulfill the requirements of Malaysian Standard MS157 (seeds) or MS2099 (clones) and subscribe to relevant certification schemes. Companies must obtain the license to produce, store, shipping and handling of the planting materials. Field performance of commercial oil palm planting materials are regularly evaluated in comparative trials.

ANALYSIS OF MULTISPECTRAL IMAGERY FROM UNMANNED AERIAL VEHICLE (UAV) USING OBJECT-BASED IMAGE ANALYSIS FOR DETECTION OF Ganoderma DISEASE IN OIL PALM

Ganoderma disease that affects oil palms has caused huge losses to the palm oil industry in Malaysia. To curb widespread infection and mitigate further losses, attempts have been made to detect infected oil palms automatically so that they can be treated or destroyed. The multispectral remote sensing technology can be employed to this effect efficiently. From the aerial images, infected oil palms can be detected and classified according to the Ganoderma Disease Severity Index (GDSI). In this study, object-based image analysis (OBIA) was performed to classify oil palms in a selected area into three classes namely; healthy (T0), moderately infected (T2) and severely infected (T3). It would be desirable if lightly infected oil palms could also be categorised as a class. However, it was extremely difficult to discriminate lightly infected oil palms from the healthy ones just by analysing the aerial images since symptoms of early infection were not evident in the fronds yet. Images of each individual band as well as those obtained by combining two, three or four bands of the available spectra were analysed. The OBIA was conducted using example-based feature extraction procedure and various OBIA settings were tested to achieve a number of classification results. The accuracies of the results are quantified by comparing the results with the ground truth data. The results suggest that the combination of Edge-based segmentation and merge algorithm using Full-Lambda Schedule (FLS), Support Vector Machine (SVM) classifier and three-band data of (G_R_NIR) scores the highest accuracy of (91.8%). When data of individual bands were tested using the same algorithm and classifier, they obtained moderate accuracies ranging from 65.5%-76.2%. However, when data of two, three and four bands were combined, better results with classification accuracies from 70%-90% were recorded. These results show that the OBIA can be used to analyse multispectral images of oil palms to detect moderate and severe infection of Ganoderma disease. Detection of early infection of Ganoderma is feasible if more advanced algorithms and classifiers can be used with multispectral and hyperspectral aerial images.

INDICATION OF OIL PALM (Elaeis guineensis Jacq.) RESISTANCE TO Curvularia LEAF SPOT DISEASE BY PR-PROTEINS PRODUCING ABILITY

Curvularia leaf spot disease of oil palm seedlings caused by Curvularia oryzae is an important disease and widespread in South-east Asia. In this study, the resistance of oil palm C. oryzae was indicated after treatment with 106 spores ml-1 of C. oryzae NK1. The PR-proteins (chitinase and β-1,3-glucanase) were detected within 24 hr. From the inoculated oil palm seedlings, lines 129 and 187 were indicated as susceptible and resistant lines, respectively based on activities of the pathogenesis-related (PR)-proteins. The chitinase and β-1,3-glucanase activities of line 187 were 14.03 ± 0.87 and 13.51 ± 1.04 U ml-1, while the respective activities of line 129 were much lower at 3.76 ± 0.41 and 4.31 ± 0.83 U ml-1 and not significantly different from control plant. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed accumulation of 22, 25 and 33 kDa in inoculated line 187, whereas protein bands of line 129 were not visible. The disease symptoms in the susceptible line appeared approximately on 10% of the leaf area after 72 hr of fungal inoculation while no leaf spot symptoms were visible in the resistant line. Thus, the resistance of oil palm against Curvularia leaf spot disease was successfully indicated based on PR-protein producing ability, prior to testing with inoculation.

TRANSCRIPTOME ANALYSIS ACROSS VARIOUS MESOCARP DEVELOPMENTAL STAGES OF MPOB-ANGOLA Dura

Angolan germplasm materials are being evaluated for their potential use in oil palm breeding programmes. Large fruits characteristic of some Angola dura palms have provided breeders with a source of favourable traits for introgression into the current planting materials. With the aim of understanding molecular regulation during mesocarp development, maturation and ripening of Angola dura palms, efforts were initiated to profile the expression of transcripts across nine different developmental stages of mesocarp tissues. A 36 675 total gene set was identified from ribonucleic acid (RNA)-Sequencing with 24 226 transcripts successfully annotated with the Plant Reference Sequence (RefSeq) Database using BLASTX, while 12 449 transcripts had no hit to any known genes. Pairwise T-test was performed using TIGR Multiexperiment Viewer and a total of 21 261 transcripts were identified as significant across all the pairwise comparisons. BLAST2GO analysis resulted in the annotation of 13 996 unigenes with various gene ontology (GO) terms. Transcripts associated with lipid metabolic process were highly expressed during lag phase preceding the lipid biosynthesis [10 to 12 weeks after anthesis (WAA)] and fruit maturation (18 to 20 WAA) stages. Further annotation of the unigenes with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway resulted in the identification of 279, 757 and 142 transcripts related to lipid metabolism, carbohydrate metabolism and hormone metabolism, respectively. Detailed analysis of the expression data revealed that certain transcripts such as KAS I, FATA, DGAT, WRI1 and bZIP showed unique expression profiles in the MPOB-Angola dura as compared to the published data. The availability of these transcriptome datasets gives an insight into the transcriptional mechanisms controlling the Angolan dura fruit development, maturation and ripening.