SCREENING THE POTENTIAL OF ENDOPHYTIC TRICHODERMA ASPERELLUM M103 AND T. HARZIANUM M108 AGAINST GANODERMA BASAL STEM ROT DISEASE IN OIL PALM SEEDLINGS BY SEED COATING TECHNIQUE

Basal Stem Rot (BSR) disease is a main constrain in oil palm cultivation. Ganoderma boninense is known as a causal agent of this disease. The intensity of BSR disease continues to increase in both the vegetative and generative phases of oil palm plantations and causes significant losses. Biological control is one of the BSR disease control techniques and is believed to be able to support sustainable oil palm cultivation. Trichoderma spp. is a group of fungal biological agents commonly used to control BSR disease. This study aims to obtain Trichoderma spp. isolates to be developed further as biocontrol agents for BSR disease. The research stages included isolation, morphology-based identification, antagonist potency testing, characterization, and identification with molecular technique. The results in this research obtained one isolate of Trichoderma strain TSU from oil palm plantation at Pematang Siantar Regency, and one isolate of Trichoderma strain TGLP from oil palm plantation at Musi Banyu Asin Regency, which inhibited the growth of G. boninense was 90.9 and 93.9% respectively through dual culture test. Inhibition tests by volatile compounds showed growth inhibition of G. boninense by both isolates were 55.2 and 70.6%. Both Trichoderma strains have the characteristics of producing chitinase, glucanase, and indole acetic acid. Furthermore, molecular identification showed that the Trichoderma strain TSU was similar to the Trichoderma yunnanense strain CBS121219 with an identity percentage of 99.11%, and Trichoderma TGLP as Trichoderma asperellum strain 1A4 with a percent identity of 99.65%. With their antagonistic ability and characteristics, the two Trichoderma spp. isolates have the potential to be further developed as biological agents for controlling BSR caused by G. boninense.

Basal stem rot (BSR) disease caused by Ganoderma boninense basidiomycetous fungus is the most economically important disease in oil palms in South East Asia. Unfortunately, there is no single most effective control measure available. Tremendous efforts have been directed in incorporation of environmentally friendly biocontrol approaches in minimizing BSR disease. This study investigated the performance of two potential biocontrol agents (BCAs), AAT0115 and AAB0114 strains recovered from oil palm on suppression of BSR in planta, and also assessed their plant-growth-promoting (PGP) performance. ITS rRNA-sequence phylogeny discriminated the two ascomycetous Talaromyces apiculatus (Ta) AT0115 and Clonostachys rosea (Cr) AAB0114 biocontrol species with PGP characteristics. In vitro studies have demonstrated both Ta and Cr are capable of reducing linear mycelial growth of G. boninense. Inoculation of individual Cr and Ta—as well as Cr+Ta consortium—induced a significant increment in leaf area and bole girth of oil-palm seedlings five months post-inoculation (MPI) under nursery conditions. At five months post-inoculation, shoot and root biomass, and nutrient contents (nitrogen, phosphorus, potassium, calcium, magnesium and boron) were significantly higher in Ta-inoculated seedlings compared to control treated with non-Ta-inoculated maize. Chlorophyll and carotenoids contents in rapidly growing oil-palm seedlings challenged with Cr, Ta or a combination of both were not negatively affected. Cr, Ta and Cr+Ta consortium treated seedlings had 4.9–60% BSR disease reduction compared to the untreated control. Co-inoculation of Cr and Ta resulted in increased BSR control efficiencies by 18–26% (compared with Cr only) and 48–55% (compared with Ta only). Collectively, Cr and Ta, either individually or in consortium showed potential as BSR biocontrol agents while also possess PGP traits in oil palm.

BackgroundThe development of basal stem rot (BSR) disease in oil palm is associated with lignin during vegetative growth and salicylic acid (SA) biosynthesis. The increase in the lignin content, SA accumulation, growth, and root biomass could indicate the resistance of oil palm seedlings to BSR disease. Therefore, although there are many studies on the interactions between the Ganoderma boninense and oil palm, research on evaluation of physiological processes, biochemistry, and molecules occurring during early internal symptoms of BSR in roots of oil palm (Elaeis guineensis Jacq.) are essential.ResultsGanoderma boninense inoculation indicated that C01, C02, and C05 seedlings were susceptible, while the other three seedlings, C03, C07, and C08, were resistant based on Ganoderma Disease Index (GDI). Infection by G. boninense in the most susceptible seedlings C05 reduced fresh weight of roots (FW) by 9.0%, and lignin content by 10.9%. The most resistant seedlings C08 were reduced by only 8.4%, and 0.2% regarding their fresh weight and lignin content, respectively. BSR disease induced SA accumulation in the most susceptible C08 and decreased peroxidase (PRX) enzyme (EC 1.11.1.7) activities in root tissues of oil palm seedlings except C07 and C08 where PRX activities remained high in the 4 months after planting. Infection with G. boninense also increased glutathione S-transferase U19-like (EgGSTU19) gene expression in the root tissues of susceptible seedlings, while laccase-24 (EgLCC24) gene expression was associated with resistance against BSR disease. Based on the relative expression of twelve genes, two genes are categorized as receptors (EgWAKL5, EgMIK1), two genes as biosynthesis signal transduction compound (EgOPR5, EgACO1), five genes as defense responses (EgROMT, EgSOT12, EgLCC24, EgGLT3, EgGSTU19), and one gene as trans-resveratrol di-O-methyltransferase-like (EgRNaseIII) predicted related to BSR infection. While two other genes remain unknown (EgUnk1, EgUnk2).ConclusionsGanoderma infection-induced SA accumulation and lignification in resistant accessions promote the seedlings root biomass. Oil palm seedlings have a synergistic physical, biochemical, and molecular defense mechanism to the BSR disease. The utilization of nucleotide-based molecular markers using EgLCC24 gene is able to detect resistant oil palm seedlings to G. boninense.

Basal stem rot (BSR) disease caused by Ganoderma boninense remains as one of the most devastating diseases of the oil palm industry especially in South East Asia. Currently there is no remedy mainly due to inability to detect BSR disease at the early stage. Therefore, early diagnostic method is vital to detect the BSR disease effectively. This study examined the potential application of acoustic tomography method to observe the internal parts of the oil palm consisting of different levels of BSR disease severity: i) healthy, ii) moderate and iii) severe. Ten oil palm trees were selected for each level of BSR disease. The tomography data of the cross-section of the oil palm trunk was measured at one meter from the stem base for each palm using acoustic measurement system known as TomoSawit. The palm was then cut down at the tomography measurement height and compared with the acquired tomography image. The results showed that the method can provide tomography images of different BSR disease severity conditions. Detailed examination of the tomography results revealed the differences in acoustic wave speed while travelling across different densities of the cross-section of the palms that contribute to the differences in tomography image characteristics. The difference in the density could be associated with the severity of the BSR disease. All the generated tomography images have shown to be similar with the actual cross-section samples of the palm. In this study, the severely infected sample shows that an estimate of 33.3 per cent and 54.7 per cent of the cross-section was already degraded, respectively. The confirmation of BSR disease was conducted using ergosterol and Ganoderma Selective Medium (GSM) assessment. It can be concluded that the acoustic tomography could be a potential solution for early detection of BSR infection in oil palm especially for field application. Keywords: Acoustic tomography, basal stem rot, early detection, oil palm, Ganoderma boninense.

Backgrounds Oil palm (Elaeis guineensis Jacq.), is the most significant and highest-yielding crop among oil-producing crops worldwide. In 2020/2022, Basal stem rot (BSR) disease was observed in six oil palm growing Districts in Ghana. Methods Field study and laboratory analysis were conducted. A random sampling technique was used to select five plantation blocks from each District. Single-point disease assessments were done using Standard Operating Procedure (SOP) with a severity scale of 0-4. Molecular assays were performed on each sample using nucleic acid as a template. ITS and GanET sequence analysis were performed along with the formation of a phylogenetic tree using the FASTA algorithm with the Fungus database from EBI and NCBI GenBank. Koch’s postulate was followed to confirm the disease. Results The disease incidence was 11.3 % with the highest severity score of 4. Basal Stem Rot (BSR) is characterised by progressive stem decay coupled with the formation of large, perennial, woody basidiocarps. The average measurement of 2-65 cm in diameter on infected palms. Culture colonies were white, striated, undulating, woolly-cottony, and creamish pigment on the reverse, depicting attributes of Ganoderma fungus. Molecular confirmation was done by combining the ITS sequence of top matches of >97% to members of the genus Ganoderma, >98% and 99.3% identity to three sequences of Ganoderma sp. (HM138671; HM138670 and HM138672) generated from strains assigned to Ganoderma ryvardenii and compared with 132 published sequences of Ganoderma isolates. Conclusion This study presents the first report of Ganoderma ryvardenii causing BSR disease on oil palm in Ghana, potentially the first in West Africa, and second in Africa. Notably, the pathogen was previously first reported to cause similar disease on oil palm in Cameroon, highlighting its emerging threat to oil palm production in the Sub-Saharan African region.

Basal stem rot (BSR) is a common plant disease that is largely responsible for high economic losses in oil palm production. Several novel techniques have recently been develop and reported in the literature for detecting BSR disease in oil palm plantations. However, studies on the application of electrical properties in detecting BSR disease in oil palm does not exist. Therefore, this paper aims to contribute to the existing knowledge by investigating the potential of dielectric constant (DC) and chlorophyll properties in detecting BSR disease in oil palms. The study involved the collection of different leaf samples namely; healthy, mild, moderate, and severely-infected. Impedance analyzer operating at a frequency range of 100 kHz–30 MHz with 300 spectral intervals and SPAD 502 were used to measure the DC and chlorophyll of the samples collected, respectively. ANOVA, Duncan's multiple range test (DMRT) and principal component analysis (PCA) were used for statistical analysis. The results of this study showed a significant relationship between DC and different severity levels of BSR disease (p < 0.0001). Specifically, BSR disease severity levels of all samples collected were clearly discriminated based on DC. Conversely, the chlorophyll content could not classify the different levels of BSR disease into distinct separate groups but two groups (healthy and BSR-infected). As such, the results demonstrated that DC and chlorophyll content at certain extend could be used as a sensing parameter for Ganoderma disease detection.

Oil palm is an important plantation commodity in Indonesia. Oil palm cultivation in Indonesia is always associated with global warming because some of its plantation’s areas are on peatlands and its management not yet environmentally friendly. A serious problem of oil palm cultivation on peatlands is the basal stem rot disease caused by the Ganoderma fungi. There is no effective method to control this disease. Biological control is an alternative method that is environmentally friendly and is the focus of current development, however, in peatland, its development was limited by the lack of information about the influence of peat environmental factors. This study aims to determine the effect of indigenous vegetation on the biological control of Ganoderma on oil palm on peat soil. The research has been conducted by examining the effect of 4 species of peat indigenous plants on the effectiveness of Ganoderma biological control on peat soil in the experimental garden. The results showed that the presence of peat indigenous plants affected the effectiveness of Ganoderma control in oil palm on West Kalimantan peat soils. The single indigenous plant Nephrolepis biserrata was able to reduce the intensity of the disease. However, the use of mixed indigenous plants N. biserrata, Asystasia intrusa, Melastoma affine, and Stenochlaena palustris actually increased the intensity of the disease. These results indicate that the management of existing peat indigenous vegetations around oil palm plantations can help reduce the Ganoderma attacks on oil palm on peat soils.

Oil palm ( Elaeis guineensis Jacq.), is the most significant and highest-yielding crop among oil-producing crops worldwide. In 2020/2022, Basal stem rot (BSR) disease was observed in six oil palm growing Districts in Ghana. Field study and laboratory analysis were conducted. A random sampling technique was used to select five plantation blocks from each District. Single-point disease assessments were done using Standard Operating Procedure (SOP) with a severity scale of 0-4. Molecular assays were performed on each sample using nucleic acid as a template. ITS and GanET sequence analysis were performed along with the formation of a phylogenetic tree using the FASTA algorithm with the Fungus database from EBI and NCBI GenBank. Koch's postulate was followed to confirm the disease. The disease incidence was 11.3 % with the highest severity score of 4. Basal Stem Rot (BSR) is characterised by progressive stem decay coupled with the formation of large, perennial, woody basidiocarps. The average measurement of 2-65 cm in diameter on infected palms. Culture colonies were white, striated, undulating, woolly-cottony, and creamish pigment on the reverse, depicting attributes of Ganoderma fungus. Molecular confirmation was done by combining the ITS sequence of top matches of >97% to members of the genus Ganoderma, >98% and 99.3% identity to three sequences of Ganoderma sp. (HM138671; HM138670 and HM138672) generated from strains assigned to Ganoderma ryvardenii and compared with 132 published sequences of Ganoderma isolates. This study presents the first report of Ganoderma ryvardenii causing BSR disease on oil palm in Ghana, potentially the first in West Africa, and second in Africa. Notably, the pathogen was previously first reported to cause similar disease on oil palm in Cameroon, highlighting its emerging threat to oil palm production in the Sub-Saharan African region.

In oil palm plantations, Basal Stem Rot (BSR) disease has been acknowledged by many researchers worldwide to be a core and consistent danger. Given this problem, the early evaluation of the disease is necessary to prevent any infection ranging from immature to mature levels within the oil palms. The main objective of this research study is to highlight several sensors and methods that are applied for disease detection at each level. This comprehensive review utilises the most recent geospatial technology together with other advanced technologies to study BSR disease remotely, based on assessments of multispectral data, hyperspectral data, electrical properties, Terrestrial Laser Scanning (TLS), spatial mapping, Intelligent Electronic Nose (e-nose), tomography techniques and RADAR sensors. This paper identifies and explains the important techniques and methods for detecting BSR disease for any researcher who has a significant interest in specifically monitoring the development of BSR disease.

Streptomyces palmae CMU-AB204T, an antifungal producing-actinomycete, as a potential biocontrol agent to protect palm oil producing trees from basal stem rot disease fungus, Ganoderma boninense

As of 2017, 2.05 ha of Indonesia’s total oil palm area has been identified as peatlands. A large-scale peatland has caused oil palm commodities to be a global concern because they are thought to have contributed to the increase in greenhouse gas emissions that have triggered climate change. This research is an effort to resolve the main problems in the cultivation of oil palm on peatlands in a more environmentally friendly way. The main obstacle to oil palm cultivation on peatlands is Ganoderma fungi attacks that cause basal stem rot (BSR) disease, where the attack is higher than in mineral soils. Biological control is a prospective alternative way to control BSR disease. However, its development in peatlands is hampered by extremely low peat pH. The possible approach is to utilize appropriate biological control agents for peatlands. This study aimed to examine antagonistic bacteria’s from peatlands to control Ganoderma under low pH conditions in vitro. The bacterial isolates from peatlands were tested for antagonism against Ganoderma and tested for their growth ability in 2-7 pH situations. The results showed that from the West Kalimantan peatlands, Ganoderma-antagonistic bacteria grew at pH 2-4, even though the growth rate had decreased significantly. The isolates were E4B6, E2B12, E2B13, B3B11, and E2B3. These results indicate that these bacteria can be used in controlling oil palm BSR disease caused by Ganoderma in peatlands.

BackgroundsOil palm (Elaeis guineensis Jacq.), is the most significant and highest-yielding crop among oil-producing crops worldwide. In 2020/2022, Basal stem rot (BSR) disease was observed in six oil palm growing Districts in Ghana.MethodsField study and laboratory analysis were conducted. A random sampling technique was used to select five plantation blocks from each District. Single-point disease assessments were done using Standard Operating Procedure (SOP) with a severity scale of 0-4. Molecular assays were performed on each sample using nucleic acid as a template. ITS and GanET sequence analysis were performed along with the formation of a phylogenetic tree using the FASTA algorithm with the Fungus database from EBI and NCBI GenBank. Koch’s postulate was followed to confirm the disease.ResultsThe disease incidence was 11.3 % with the highest severity score of 4. Basal Stem Rot (BSR) is characterised by progressive stem decay coupled with the formation of large, perennial, woody basidiocarps. The average measurement of 2-65 cm in diameter on infected palms. Culture colonies were white, striated, undulating, woolly-cottony, and creamish pigment on the reverse, depicting attributes ofGanoderma fungus. Molecular confirmation was done by combining the ITS sequence of top matches of >97% to members of the genusGanoderma, >98% and 99.3% identity to three sequences ofGanoderma sp. (HM138671; HM138670 and HM138672) generated from strains assigned toGanoderma ryvardenii and compared with 132 published sequences ofGanoderma isolates.ConclusionThis study presents the first report ofGanoderma ryvardenii causing BSR disease on oil palm in Ghana, potentially the first in West Africa, and second in Africa. Notably, the pathogen was previously first reported to cause similar disease on oil palm in Cameroon, highlighting its emerging threat to oil palm production in the Sub-Saharan African region.

Despite massive economic contributions to Malaysia, the oil palm industry faces devastating threats from basal stem rot (BSR) disease. An array of treatments was designed to evaluate the potential of biological control agents (BCAs) as a single and combination of applications in a greenhouse study of six months. Oil palm enzymes, phenolic content, and metabolite induction in BSR-diseased seedlings were also assessed in response to the designed treatments. In the study, seedlings treated with Trichoderma asperellum (UPM16) demonstrated the highest disease reduction (DR) (57.2%). Peroxidase (PO), lignin, and total phenolic content (TPC) were evaluated. Treatments on Ganoderma-infected seedlings treated with Bacillus cereus (UPM15) exhibited the highest reading in all assays. Gas chromatography-mass spectrometry (GC-MS) analysis profiled phenol, 4-2-aminoethyl- as the most abundant metabolite detected in combination treatments with B. cereus and T. asperellum (BT). Both BCAs complimented and demonstrated huge potential in mitigating BSR diseases in oil palm. However, excessive chemical application to control BSRs negatively impacts biodiversity and the human population. In view of this, studies on biological control are crucial in selecting potential BCAs to counter BSR sustainably. Biological control would be an ideal alternative as a sustainable method for controlling oil palm BSR disease.

The effect of arbuscular mycorrhizal fungi (AMF) in combination with endophytic bacteria (EB) in reducing development of basal stem rot (BSR) disease in oil palm (Elaeis guineensis) was investigated. BSR caused by Ganoderma boninense leads to devastating economic loss and the oil palm industry is struggling to control the disease. The application of two AMF with two EB as biocontrol agents was assessed in the nursery and subsequently, repeated in the field using bait seedlings. Seedlings pre-inoculated with a combination of Glomus intraradices UT126, Glomus clarum BR152B and Pseudomonas aeruginosa UPMP3 significantly reduced disease development measured as the area under disease progression curve (AUDPC) and the epidemic rate (R L) of disease in the nursery. A 20-month field trial using similar treatments evaluated disease development in bait seedlings based on the rotting area/advancement assessed in cross-sections of the seedling base. Data show that application of Glomus intraradices UT126 singly reduced disease development of BSR, but that combination of the two AMF with P. aeruginosa UPMP3 significantly improved biocontrol efficacy in both nursery and fields reducing BSR disease to 57 and 80%, respectively. The successful use of bait seedlings in the natural environment to study BSR development represents a promising alternative to nursery trial testing in the field with shorter temporal assessment.

Basal Stem Rot (BSR) disease attacks in oil palm plantations are still the most significant cause of losses in oil palm plantations. The leading cause of BSR disease in oil palm plants is the Ganoderma Boninense fungus. The spread of BSR in an oil palm area can be massive due to transmission through root contact, airborne, and sporophores spread on the soil and in dead plant debris. The application of advanced technologies to mitigate and prevent the spread of BSR disease can be carried out considering that the nature of the spread and characteristics of this disease infection are well known. Advanced technologies such as the Internet of Things (IoT) are suitable for real-time monitoring of large areas. The key to successfully detecting BSR disease in oil palm plants is the selection of sensor technologies for monitoring and machine learning models used for segmenting and classifying infected plant characteristics. This paper comprehensively summarizes the spread of BSR disease and then describes various technologies and machine learning models for monitoring and preventing BSR disease in oil palm plantations. Hopefully, this paper can complement and provide a basis for developing technology to prevent the spread of BSR disease.