Stem Rot Of Oil Palm Research Articles

Evaluation of new generation fungicides against Ganoderma induced basal stem rot of oil palm

Basal stem rot (BSR), incited by Ganoderma spp. poses a significant challenge to the oil palm industry in India. A total of ten roots and basidocarps samples were taken from BSR-infected fields of Pedavegi, Andhra Pradesh, and identified as Ganoderma based on distinctive colony characters. To enhance identification accuracy, PCR with GB4 genus-specific primers, resulting in a 500 bp amplicon that confirmed the isolate affiliation with the Ganoderma genera. The efficacy of 13 fungicides against Ganoderma was evaluated through solid plate assay. Noteworthy inhibition of mycelial radial growth was observed with the eight fungicides at all tested doses, including Hexaconazole 5 per cent SC, Propiconazole 25 per cent EC, Tebuconazole 25.9 per cent EC, Tebuconazole 50% + Trifloxystrobin 25% w/w WG, Propiconazole 13.9% + Difenconazole 13.9%, Fluopyram 17.7% w/w + Tebuconazole 11.4% SC, Azoxystrobin 8.3% + Mancozeb 66.7% WDG and Pyraclostrobin 5% + Metiram 55% WG. Complete inhibition was achieved at 2000 and 4000 ppm with Triflumizole 42.14% SC and Azoxystrobin 18.2% + Difenoconazole 11.4% SC. Additionally, the liquid broth assay validated the efficacy of five fungicides in hindering mycelial dry weight. Furthermore, effective strategies against BSR, such as root feeding, stem injection and soil drenching, emerged as valuable insights for the integrated Ganoderma management in plantation crops.. KEYWORDS :Basal stem rot, fungicides, Ganoderma, management, oil palm

Basal stem rot of oil palm: Disease development in mineral and peat soils

Basal stem rot (BSR) of oil palm, caused by Ganoderma boninense, is a major disease of economic concern in Southeast Asia, especially in Indonesia and Malaysia. The disease causes palm death and the reduction in the oil palm stand, results in lower yields and serious economic losses. In Indonesia, incidence of BSR has been reported in both mineral and peat soils. To control BSR in peat and mineral soils, an understanding of disease development is necessary. Disease developmental studies were conducted at two oil palm plantations in North Sumatra, representing mineral and peat soils. Palms with mild BSR infection were recorded and disease progression monitored. After 37 months, critical symptoms of basal stem rotting were observed. The percentages of palms with advanced disease symptoms in mineral and peat soils were 62.5% and 90.6%, respectively. The observations indicated that BSR symptoms developed faster in oil palms planted in peat soil compared to those in mineral soils.

Symptomatology, Distribution and Incidence of Basal Stem Rot of Oil Palm in Côte d'Ivoire

The oil palm (Elaeis guineensis Jacq.) is a tree plant cultivated for its fruits, from which fatty substances are extracted for food and industrial uses. The oil palm sector has a positive impact on the socio-economic situation of producing countries such as Côte d’Ivoire. However, oil palm cultivation is subject to pests and pathologies, such as basal stem rot, which have been attacking Ivorian palm groves for several decade. This study was carried out to assess the spatial distribution and incidence of this pathology in the traditional oil palm cultivation area in Côte d'Ivoire. The method adopted for this study consisted of making an inventory of all the palm trees in a given plot, noting the presence or absence of symptoms of the disease and determining the incidence in each locality. The characteristic symptoms of the disease were observed: a pale appearance of the leaves, the arrows not open, the appearance of carpophore at the base of the stem or on root. Disease is present in the localities of Ehania, Eloka, Anguédédou, Boubo and Okroyo. But absent from the locality of Iboké. The incidence of the disease was between 0% Iboké and Ehania 1.15 %. This study establishes for the first time a summary map of the distribution of basal rot of the oil palm in Côte d'Ivoire

Basal Stem Rot of Oil Palm - The Pathogen, Disease Incidence, and Control Methods.

Basal stem rot of oil palm caused by Ganoderma boninense is the most serious disease of oil palm in Malaysia, Indonesia, and other oil palm producing countries. Economic losses caused by the disease can be up to USD500 million a year. For many years, basal stem rot was found to infect older palms of over 25 - 30 years. Only in the 1950s, the disease began to appear in much younger palms (10 to 15 years old) and in the last decade or so, palms as young as 1 year were infected by the disease. The highest incidence occurs in coastal areas of Southeast Asia but the disease has now infected oil palm in inland areas, mainly oil palm planted in peat soils. Disease incidence is also high in areas previously growing coconut or forest. Basal stem rot infection and spread occur through root-to-root contact, and basidiospores that colonize the roots also play a role. In the early stages of infection by G. boninense, the pathogen behaves as a biotroph and later as a necrotroph, secreting cell wall-degrading enzymes and triggering host defense responses. Genes, gene products and metabolic pathways involved in oil palm defense mechanisms against G. boninense have been identified, and these metabolites have the potential to be used as markers for early detection of the disease. Integrated disease management used to control basal stem rot includes cultural practices, chemical control, and application of biocontrol agents or fertilizers. Early detection tools have also been developed which could assist in management of basal stem rot infections. Development of resistant or tolerant oil palm is still at an early stage, so the existing integrated disease management practices remain the most appropriate methods for managing basal stem rot of oil palm.

Panoramic Over View of Advancements in the Arena of Detection and Management of Basal Stem Rot of Oil palm caused by Ganoderma sp

Panoramic Over View of Advancements in the Arena of Detection and Management of Basal Stem Rot of Oil palm caused by Ganoderma sp

Basal stem rot of oil palm incited by Ganoderma species: A review

Basal stem rot of oil palm incited by Ganoderma species: A review

Basal stem rot of oil palm revisited

AbstractBasal stem rot caused by Ganoderma boninense is the single major disease to affect oil palms in South Asia and Oceania. Although first described in commercial plantations some 90 years ago it remains a major constraint to oil palm planting, with disease occurence increasing with succesive plantings. There is a considerable volume of published research into the occurence, diagnostics and control of basal stem rot but much of this has been focused on individual plantings or local environments. In this manuscript we attempt to bring together reports from across the South Asia/Oceania regions to provide a comprehensive review of the current knowledge and to identify the key issues that still need to be addressed in order to achieve a comprehensive understanding of the disease and disease processes.

In vitro antagonistic activity of soil microbes isolated from oil palm to Ganoderma zonatum

Ganoderma zonatum is the causal agent of basal stem rot of oil palm (Elaeis guineensis Jacq) in Riau. The research objective was to explore and select soil microbial antagonists to Ganoderma zonatum. Soil samples were taken from the non/rhizosphere of 27 oil palm plants in Kampar and Siak Regency, Riau Province, Indonesia, in 2018-2019. The soil microbes were grown on Potatoes Dextrose Agar for fungus and Tryptic Soy Agar for the bacterium. The antagonist was measured by a dual culture method. The colony diameter of G. zonatum the (dual) culture was measured to assess the inhibition potency of the potential microbial antagonists. The soil microbial collected was 138 isolates, including 58 of Trichoderma spp. and 80 of bacteria. The inhibition against the isolated soil microbes to G. zonatum growth ranged from 46-74% for Trichoderma spp. and 0-86% for the bacterium. Seven isolates of Trichoderma spp and 13 of bacterial inhibited G. zonatum growth >70%, have potential as biocontrol agents. Two isolates that showed the most potential as antagonists, i.e Trichoderma harzianum (AC2, rhizosphere) and Burkholderia gladioli (N1, non-rhizosphere) could be developed for further as microbial antagonists.

Aktivitas Pelapukan Kayu Inokulum Ganoderma boninense pada Tumpangsari Bibit Kelapa Sawit dan Talas-Talasan

Basal stem rot of oil palm caused by Ganoderma boninense is difficult to be controlled due to abundance of inoculum sources in the field. This study was aimed to determined effects of taro plants viz. Belitung taro ( Xanthosoma sagittifolium ), Bogor taro ( Colocasia esculenta ), and Japanese taro ( Colocasia esculenta var. antiquorum) on decay of G. boninense inocula. Pathogen inocula as rubber wood block (RWB) colonized by G. boninense was attached with main roots of oil palm seedling and buried into soil of oil palm seedling (monoculture), mixed planting of oil palm and taro plants, or of taro plants monoculture. Burying of pathogen inocula for 3 and 6 months on taro plant resulted in 2.1 times higher decay of RWB compared than oil palm monoculture. Increasing of decay also exhibited on mixed cropping system, but it was slightly lower than on oil palm monoculture. This result suggesting the benefit of taro plants either planted under monoculture or mixed cropping to fasten decomposition of infected wood debris as an inoculum source of G. boninense .

A preliminary study to identify and distinguish southern tropical populations of Ganoderma boninense from oil palm via mating assays, sequence data, and microsatellite markers

ABSTRACT Morphological studies suggest that the major pathogen causing basal stem rot of oil palm in Papua New Guinea and Solomon Islands is Ganoderma boninense. This study presents the first evidence for conspecificity of G. boninense from four countries where basal stem rot is prevalent. Seventy-three dikaryotic isolates of Ganoderma boninense from Indonesia, Malaysia, Papua New Guinea, and Solomon Islands were studied via mating tests, analyses of nuc internal transcribed spacer ITS1-5.8S-ITS2 sequences, and microsatellite genotyping. Sequence similarity in the ITS1-5.8S-ITS2 region was >99%, and all exotic isolates successfully mated with Papua New Guinea tester strains. Transfer of nuclei during mating was also confirmed via microsatellite markers for the first time in this species. Four microsatellite primers were used to generate evidence for 33 alleles in the four populations. All isolates studied had unique genetic fingerprints but alleles were also shared, suggesting gene flow. Heterozygosities were lower than expected in Indonesian and Papua New Guinea populations, consistent with the possibility of localized inbreeding.

Current strategies and perspectives in detection and control of basal stem rot of oil palm.

The rapid expansion of oil palm (OP) has led to its emergence as a commodity of strategic global importance. Palm oil is used extensively in food and as a precursor for biodiesel. The oil generates export earnings and bolsters the economy of many countries, particularly Indonesia and Malaysia. However, oil palms are prone to basal stem rot (BSR) caused by Ganoderma boninense which is the most threatening disease of OP. The current control measures for BSR management including cultural practices, mechanical and chemical treatment have not proved satisfactory. Alternative control measures to overcome the G. boninense problem are focused on the use of biological control agents and many potential bioagents were identified with little proven practical application. Planting OP varieties resistant to G. boninense could provide the ideal long-term solution to basal stem rot. The total resistance of palms to G. boninense has not yet been reported, and few examples of partial resistances have been observed. Importantly, basidiospores are now recognized as the method by which the disease is spread, and control methods require to be revaluated because of this phenomenon. Many methods developed to prevent the spread of the disease effectively are only tested at nursery levels and are only reported in national journals inhibiting the development of useful techniques globally. The initial procedures employed by the fungus to infect the OP require consideration in terms of the physiology of the growth of the fungus and its possible control. This review assesses critically the progress that has been made in BSR development and management in OP.

Depletion of Indonesian oil palm plantations implied from modeling oil palm mortality and <i>Ganoderma boninense</i> rot under future climate

Currently there are increasing land-cover and land-management issues related to oil palm plantations. Palm oil is highly valuable and it is added to numerous commodities internationally with Indonesia being the most voluminous producer. The cultivation of oil palm affects the environment negatively, per se, threatening plantation sustainability from deforestation. Furthermore, the fungus Ganoderma boninense causes basal stem rot of oil palm, a major problem for plantation managers in Indonesia. Suitable future climate for growth of Indonesian oil palm, determined by employing the simulation programme, CLIMEX, has already been employed to create scenarios of oil palm mortality and diseases. This was achieved by combining CLIMEX with narrative models, a technique often employed in climate studies. Determinations of the percentage of oil palm that survive climate and do not have basal stem rot have also been provided. The current paper considers these scenarios for Indonesia and regions for the first time. The models assume no change in the future climate scenarios and that effective mitigation is not taken. The effects on plantation sustainability are considered. Climate will not affect the incidence of basal stem rot greatly until 2050, but the situation will deteriorate thereafter. Sumatra and Java are especially affected and plantations may be unsustainable quickly, whereas Papua and Sulawesi may be able to sustain the crop longer. However, deforestation in Papua and Sulawesi is highly undesirable. Methods to manage climate effects on oil palm and reduce basal stem rot are described. Plantation managers can use the earlier assessments herein to indicate if the later ones are accurate and plan to ameliorate the problems. Conclusions indicate that palm oil production may be unsustainable in Indonesia by 2050 from loss of plantations thus requiring action immediately.

First Report of Basal Stem Rot on Oil Palm Caused by Thielaviopsis paradoxa in Hainan, China

Oil palm (Elaeis guineensis) is one of the most widely grown and distributed oil plants in southern Asia. It is usually grown as a garden ornamental in China. A serious basal stem rot disease was observed on young oil palm (Tenera variety) during the months of October and December in 2017 in Wenchang, Hainan Provence, China, at several locations. A survey of 100 2-year-old oil palm plants revealed that the disease caused serious damage during the typhoon season of Hainan Province, with 20 to 25% incidence in plants. The leaf symptoms included wilting and necrosis, beginning with the lowest leaves in the canopy. Cross-sections revealed brown rot confined to one side of the basal stem, where the rot was spreading inward from the surface. Diseased stem tissues from six trees in two palm gardens were collected and cut into 5-mm cubes. After tissue collection, surface sterilization was performed by the immersion of the previously washed plant tissue in ethanol (75%) for 1 min and then in hypochlorite (0.1%) for 1 min; it was then rinsed with sterile distilled water and cultured on potato dextrose agar (PDA) at 25°C. A fungus was isolated from lesion margins of diseased oil palm trees. Colonies on PDA were initially white and downy, becoming black and velvety after 2 days and emitting a fruity odor. The fungus produced conidia, which were cylindrical, colorless to pale brown, and 6.1 to 13.2 × 3.4 to 5.8 μm (n = 50). Chlamydospores were terminal, in chains, obovate to oval, thick walled, brown, and 7.3 to 18.9 × 4.4 to 11.7 µm (n = 50). Conidiophores were straight, sometimes sinuous at the base, hyaline to pale brown, septated at the base, smooth, and producing a succession of conidia through the open end. The morphological characteristics and measurements of this fungal isolate matched the previous descriptions of Thielaviopsis paradoxa (De Seynes) Hohn. (Morgan-Jones 1967). For the molecular characterization, sequences of the internal transcribed spacer (ITS) regions were amplified from isolates using the primer pair ITS1/ITS4. A BLAST search of GenBank showed that the ITS (MG706124) sequences of the isolate were 99% homologous with T. paradoxa strain PG3 (GenBank accession no. KF312152). A maximum likelihood tree was generated by MEGA6.0, and isolate OPC3 clustered together with T. paradoxa strain PG3 (98% bootstrap). For a pathogenicity test, three 2-year-old healthy basal stems were wounded with a fine needle and inoculated with mycelial plugs (5-mm-diameter plugs), and another set of three basal stems were treated with pure PDA plugs as a control. All stems were placed in a growth chamber at 25°C and 90% relative humidity. The pathogenicity test was repeated three times. Two weeks after inoculation, all the inoculated rachises showed typical symptoms, and a rusty brown lesion appeared at the points of inoculation. No symptoms were observed on the controls. The fungus was reisolated from the infected tissues, fulfilling Koch’s postulates. The results obtained on morphological characteristics, pathogenicity, and molecular data corresponded with those of T. paradoxa. T. paradoxa has been reported as causing rot diseases on coconut (Yu et al. 2012), pindo palm (Tang et al. 2014), and triangle palm (Yu et al. 2016) in HaiNan. To our knowledge, this is the first report of basal stem rot of oil palm caused by T. paradoxa in China. Given its wide host range, T. paradoxa has great potential to become an economically important plant pathogen.

Basidiospores as sources of inoculum in the spread of Ganoderma boninense in oil palm plantations in Papua New Guinea

Basal and upper stem rot of oil palm is caused by the agaricomycete Ganoderma boninense. This study investigated the transmission of basal stem rot from Ganoderma‐infected oil palm stumps to young oil palm seedlings. Low seedling mortalities (2.5%) were observed in a field trial after 24 months, but G. boninense could be detected in the rachis, bole and roots of a significant proportion of seedlings that were outwardly healthy. A high level of genetic heterogeneity amongst G. boninense isolates within the trial area was revealed. Furthermore, germinated seedlings growing in close proximity to infected palms in a mature oil palm field contained multiple isolates of G. boninense indicating that colonization of roots by basidiospores and dikaryons, arising from mating between basidiospores, is a common occurrence in oil palm plantations. The probability that basidiospores are a direct source of inoculum in addition to diseased trunk tissue is discussed as a means of explaining the observed heterogeneity in populations of G. boninense on oil palm. Such a scenario presents challenges for the long‐term management of basal stem rot.

Streptomyces sanglieri which colonised and enhanced the growth of Elaeis guineensis Jacq. seedlings was antagonistic to Ganoderma boninense in in vitro studies.

Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784(T) and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 10(9) cfu/ml showed significant (P < 0.05) increase in oil palm seedlings growth when compared to the control. Streptomyces sanglieri strain AUM 00500 successfully colonised the epidermal surface of the roots of treated oil palm seedlings and it was recovered from root fragments plated on starch casein agar.

Scytalidium parasiticum sp. nov., a New Species Parasitizing on Ganoderma boninense Isolated from Oil Palm in Peninsular Malaysia

A mycoparasite, Scytalidium parasiticum sp. nov., isolated from the basidiomata of Ganoderma boninense causing basal stem rot of oil palm in Johor, Malaysia, is described and illustrated. It is distinct from other Scytalidium species in having smaller asci and ascospores (teleomorphic stage), longer arthroconidia (anamorphic stage), hyaline to yellowish chlamydospores, and producing a fluorescent pigment. The phylogenetic position of S. parasiticum was determined by sequence analyses of the internal transcribed spacers and the small-subunit ribosomal RNA gene regions. A key to identify Scytalidium species with teleomorphic stage is provided.

Ergosterol analyses of oil palm seedlings and plants infected with Ganoderma

Basal stem rot of oil palm (OP) by Ganoderma boninense is of major economic concern and it is the predominant disease of OP in SE Asia. Also, other plantation crops are affected by Ganoderma. The early detection of symptoms is crucial for control, although effective methods remain elusive. Ergosterol is the principal sterol of fungi and plays an essential role in the cell membrane and other cellular constituents. The analysis of ergosterol is useful for fungal detection in solid plant substrates. The present report compares ergosterol concentration in sound and decayed OP seedlings and mature plants using HPLC with diode array detection. The disease of OP requires to be considered as a white rot process where fungal biomass will increase from a low to high level as the infection progresses. G. boninense biomass was correlated with ergosterol concentration in vitro. Furthermore, the sterol was correlated with internal colonization (a) of inoculated seedlings, (b) of felled and standing OP and (c) to external symptoms of the disease. The compound was not detected in healthy samples. Disease treatments may be made more effective as the amounts of fungal biomass can be estimated and early detection is possible. Ergosterol quantification is a provisional diagnostic method for detection for G. boninense infection in OP which can be employed with other methods, enabling early remedial action to be taken. The method is recommended for further research involving basal stem rot of OP.

Preliminary Studies on the Development of Monoclonal Antibodies Against Mycelia of Ganoderma boninense, the Causal Pathogen of Basal Stem Rot of Oil Palm

This study aimed to raise specific MAbs against G. boninense , the causal pathogen of basal stem rot (BSR) of oil palm. Crude mycelium extract of G. boninense was used as immunogen to generate MAbs. Mycelium was harvested from liquid culture and freeze-dried followed by re-suspension in phosphate buffer saline (PBS). Two 10-week old BALB-C mice were immunized with the mycelial extract. The mice were boosted once before harvesting their spleens for fusion. The MAbs were fused with myeloma cells from BALB-C mice. Initial screening was carried out using plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) with mycelial immunogen of G. boninense . The MAbs with positive signals were verified via secondary screening and cloned for cross-reactivity test. Cross-reactivity testing was carried out with 2 other fungi namely; Trichoderma and Botrytis along with 2 different species of Ganoderma commonly found in oil palm plantations namely; G. zonatum , and G. miniatocinctum . This study found that the MAbs raised against G. boninense were not specific as the MAbs gave positive signals through the cross-reactivity test with all fungi tested in the cross-reactivity. Future work would be using these MAbs in a co-immunization program whereby the generated Ganoderma sp generic monoclonal antibody will be pre-mixed with the G. boninense mycelium immunogen to allow reduction in the potential cross-reactivity of newly generated antibodies with Ganoderma sp. Our efforts are also currently directed at optimizing the immunogen preparation for the production of MAbs specific to G. boninense .

Quantification and characterisation of Trichoderma spp. from different ecosystems

Basal stem rot of oil palm caused by Ganoderma boninense is of major economic importance. Observations of the low incidence of disease due to Ganoderma species in natural stands, suggest that the disease is kept under control by some biological means. Trichoderma spp. are saprophytic fungi with high antagonistic activities against soil-borne pathogens. However, their abundance and distribution are soil and crop specific. Trichoderma species have been found to be concentrated in the A1 (0-30 cm) and Be soil horizons (30-60 cm), although the abundance of Trichoderma was not significantly different between the oil palm and non-oil palm ecosystems. Characterisation of Trichoderma isolates based on cultural, morphological and DNA polymorphism showed that T. harzianum, T. virens, T. koningii and T. longibrachiatum made up 72, 14, 10 and 4% of the total Trichoderma isolates isolated. As Trichoderma species are present in the oil palm ecosystem, but at lower numbers and in locations different from those desired, soil augmentation with antagonistic Trichoderma spp. can be developed as a strategy towards integrated management of basal stem rot of oil palm.

Genetic structure of a population of Ganoderma boninense on oil palm

Ganoderma boninense (the causal agent of basal stem rot of oil palm in Papua New Guinea) has a tetrapolar mating system with multiple alleles. Investigations into the population structure of G. boninense, using interfertility between isolates as a marker, revealed that the population on oil palm was comprised predominantly of genetically distinct individuals, although a number of isolates were found to share single mating alleles. No direct hereditary relationship was found between isolates on neighbouring or spatially separated diseased palms, indicating that outcrossing had probably occurred over several generations in the founder population prior to colonization of oil palm. In this study, a total of 81 A and 83 B mating type alleles (factors) were detected with 18 allelic repeats at the A locus and 17 at the B locus. Alleles appeared to be randomly dispersed throughout the population in each study block, although there was a significantly (P &lt; 0·01) higher proportion of allelic repeats between estates separated by several kilometres compared to within estates. This is the first study on the population structure of this species and confirms that sexual reproduction is a significant component of the epidemiology of this disease.