Antagonistic Fungi Research Articles

Wood microbiome variation and interactions with fungal symbionts of invasive ambrosia beetles

The microbiomes of plants can modulate the impacts of pests, including through interactions with microbiomes of pathogen vectors such as ambrosia beetles. While physical and chemical traits of plant hosts are known to affect beetle-carried microbes, how beetle and host microbiomes interact is seldom explored. We aimed to determine whether wood-inhabiting endophytes mediate host susceptibility to Fusarium dieback, an emergent tree disease complex that includes ambrosia beetle vectors. We studied three competent host tree species (Persea americana, Salix spp., Platanus racemosa) common in disease hot spots in agricultural and wildland habitats. Using culturing methods, we compared wood microbiomes of 319 attacked and 133 non-attacked trees across a network of 47 beetle-infested and 41 non-infested plots in southern California, USA. We conducted 1,148 in vitro assays to evaluate antagonism by wood-inhabiting endophytic fungi (60 species) and bacteria (40 species) to the Fusarium pathogens, finding 15 fungal and 11 bacterial species with clear antagonism to the pathogen. Such wood endophytes may potentially protect tree hosts as biological control agents. Antagonistic microbes were more common in attacked trees than in non-attacked trees, suggesting the abundance of antagonistic fungi and bacteria in the wood is insufficient to determine host susceptibility to attack or they are enriched in attacked trees. Wood-inhabiting microbial communities were consistently different between cultivated P. americana and wildland tree species, as there were some differences based on host attack status. Differences between attacked and non-attacked trees were reflected in different microbial consortia rather than the abundance of individual, antagonistic microbial species.

Evaluation of Rain Shelter Cultivation Mode Effects on Microecological Environment of Mountain Cultivated Ginseng Rhizosphere

Rainfall, particularly in continental climates with a monsoonal tendency, impacts the microbial niches during the growth of mountain cultivated ginseng. With shifts in the microbial community, diseases in ginseng cultivated and protected under rain shelter conditions may ultimately be altered. Such cultivation may influence microflora dynamics through variations in meteorological parameters; however, this is not yet clear. The present study found that rain shelter cultivation affected the distribution of fungal communities within mountain cultivated ginseng. This led to an improved community structure in the ginseng rhizosphere, characterized by the proliferation of antagonistic fungi and a reduction in pathogenic fungi. A correlation analysis of meteorological factors found that soil temperature and humidity were the primary meteorological factors affecting mountain cultivated ginseng. It is evident that rain shelter cultivation regulated the microecological environment of the mountain cultivated ginseng’s rhizosphere and resulted in positive outcomes. A disease investigation supported this finding. The incidence of ginseng root diseases, such as rust and root rot, was reduced by 5–6%. The incidence of ginseng leaf diseases, including gray mold and black spot, was reduced by 5–10%. This research provides evidence to address the dynamics of microbial ecology under rain shelter cultivation and its benefits for sustainable mountain cultivated ginseng management.

Repeated horizontal acquisition of lagriamide-producing symbionts in Lagriinae beetles.

Microbial symbionts associate with multicellular organisms on a continuum from facultative associations to mutual codependency. In the oldest intracellular symbioses there is exclusive vertical symbiont transmission, and co-diversification of symbiotic partners over millions of years. Such symbionts often undergo genome reduction due to low effective population sizes, frequent population bottlenecks, and reduced purifying selection. Here, we describe multiple independent acquisition events of closely related defensive symbionts followed by genome erosion in a group of Lagriinae beetles. Previous work in Lagria villosa revealed the dominant genome-eroded symbiont of the genus Burkholderia produces the antifungal compound lagriamide, protecting the beetle's eggs and larvae from antagonistic fungi. Here, we use metagenomics to assemble 11 additional genomes of lagriamide-producing symbionts from seven different host species within Lagriinae from five countries, to unravel the evolutionary history of this symbiotic relationship. In each host, we detected one dominant genome-eroded Burkholderia symbiont encoding the lagriamide biosynthetic gene cluster. However, we did not find evidence for host-symbiont co-diversification, or for monophyly of the lagriamide-producing symbionts. Instead, our analyses support a single ancestral acquisition of the gene cluster followed by at least four independent symbiont acquisitions and subsequent genome erosion in each lineage. By contrast, a clade of plant-associated relatives retained large genomes but secondarily lost the lagriamide gene cluster. Our results, therefore, reveal a dynamic evolutionary history with multiple independent symbiont acquisitions characterized by a high degree of specificity, and highlight the importance of the specialized metabolite lagriamide for the establishment and maintenance of this defensive symbiosis.

Assessment of Chinese Medicinal Herbal Wastes Compost Inoculated with Antagonistic Fungi: Nitrogen Retention and Microbial Community in Phytopathogenic Soil

Assessment of Chinese Medicinal Herbal Wastes Compost Inoculated with Antagonistic Fungi: Nitrogen Retention and Microbial Community in Phytopathogenic Soil

Screening and identification of antagonistic fungi against pepper anthracnose and investigation into its pot-plant control effects

Screening and identification of antagonistic fungi against pepper anthracnose and investigation into its pot-plant control effects

<i>In vitro</i> studies on the development of microbial consortia for the management of major diseases in coconut and citrus

Microbial consortia for disease suppression involve combining multiple beneficial microorganisms to enhance their effectiveness in plant disease management. In present study, development of microbial consortia for the management of major diseases in coconut and citrus was carried out using bacteria Pseudomonas fluorescens, Pseudomonas putida (striata), Bacillus subtilis and fungi – Trichoderma reesei, T. harzianum, T. asperellum against major pathogens viz. Ganoderma lucidum, Thielaviopsis paradoxa, Phytopthora palmivora, Lasiodiplodia theobromae isolated from the coconut rhizosphere, and Fusarium solani isolated from the citrus rhizosphere. The promising fungal and bacterial antagonists were identified and studied for compatibility. Non-volatile compounds of consortia inhibited the test pathogens with an increase in concentration from 10 % to 75% with fungal consortia and bacterial consortia and also with mixed consortia which is composed of bacterial consortia + fungal consortia. Superior growth suppression was recorded with mixed consortia even at 10% concentration (59.44% to 65.83%) against the test pathogens in the ascending order of L. theobromae (59.44%) T. paradoxa (63.89%), G. lucidum (65.83%), P. palmivora (63.61%) and F. solani (62.78%). A similar trend was observed in 75% concentration where inhibition observed in the order of Thielaviopsis paradoxa (90.28%), G. lucidum (89.44%), F. solani (82.50%), L. theobromae (81.94%) and P. palmivora (81.39%). Volatile effect by bacterial consortia recorded the superior inhibition on test pathogens in the order of Ganoderma (85.28%), F. solani (75.28%), T. paradoxa (71.94%), P. palmivora (71.67%) and L. theobrome (67.50%) compared to the individual bioagents. Similarly, the fungal consortia showed the superior inhibitory effect on test pathogens in the order of G. lucidum (83.25%), P. palmivora (82.50%), L. theobromae (83.06%), F. solani (80.56%) and T. paradoxa (73.61%). Since there was no zone of inhibition between the strains, the interactions between Pseudomonas and Bacillus strains of Trichoderma spp. were compatible with one another. Neem cake recorded superior CFU population from 9.43 X 106 CFU at seven days by T. asperellum. Shelf life study on mixed consortia with bacterial + fungal bioagents in talc formulation indicated that all the bacterial and fungal CFU count recorded in 106 dilution for 90 days.

Sustainable management of blister and grey blight diseases of tea using antagonistic and plant growth promoting microbes in Western Ghats of India

The blister and grey blights are the devastating leaf diseases in tea. The severity of blister and grey blight diseases in tea ranged from 22% to 68% and 11.41%–57.02%, respectively in a survey conducted in Southern India during 2022–2023. The morphological and molecular identifications of pathogens revealed that Exobasidium vexans and Neopestalotiopsis clavispora were responsible for causing blister and grey blights on tea in southern India. The conventional management strategy with foliar spray of synthetic fungicides result in fungicidal residue in tea causes environmental pollution and health hazards to human. To overcome this the current study aims to manage the blister and grey blight diseases of tea through the microbial biocontrol agents. The bacterial biocontrol agents viz., Bacillus subtilis (BBV57), Bacillus amyloliquefaciens (TNAU), Pseudomonas fluorescens (Pf1) and the fungal antagonist, Trichoderma asperellum (TV 1) were evaluated for their efficacy against the both blight diseases. All the bio agents have significantly reduced the basidiospore germination and the mycelial growth of E. vexans and N. clavispora, respectively. Among the bio agents, B. amyloliquefaciens registered 88.36% reduction in the germination of E. vexans basidiospore and 85.56% of mycelial growth reduction of N. clavispora in vitro (P < 0.05). Under field conditions the combined soil and foliar application of bacterial antagonists viz., B. subtilis, B. amyloliquefaciens and P. fluorescens each with 1 ˟ 1011 CFU/ml @ 5% concentration at 7 days interval significantly reduced the blister blight incidence with 53.53% & 51.53% reduction over control and 51.53% & 43.65% of reduction over initial during first and second year, respectively. The combined application also reduced the grey blight incidence with 53.53% & 52.00% reduction over control and 56.81% & 47.65% of reduction over initial during first and second year, respectively. This treatments with bioagents were almost comparable with synthetic treatments, such as copper oxy chloride (0.25%) and hexaconazole (0.25%) with 64.63% and 64.76% reduction of blister and grey blight reduction in first year; 59.74%, 51.11% reduction in second year over control (P < 0.05), respectively. Thus, the application of B. subtilis, B. amyloliquefaciens and P. fluorescens can be recommended for the sustainable management of tea blister and grey blight diseases in tea gardens.

Plant defense compounds can enhance antagonistic effects against Alternaria brassicicola of seed-associated fungi isolated from wild Brassicaceae.

Plant microbiota appear more and more as potential sources of antagonistic microorganisms. However, the seed microbiota associated with wild plant species has rarely been explored. To identify fungal antagonists to the seed-borne pathogen Alternaria brassicicola, seeds were collected in natural populations of three Brassicaceae species, Arabidopsis thaliana, Capsella bursa-pastoris and Draba verna. A large number of fungal strains reduced the growth of A. brassicicola. The most antagonistic strains belonged to Alternaria, Apiospora, Trichoderma and Aspergillus. Seed-associated fungi tolerated host plant defenses and exhibited lower sensitivity compared to A. brassicicola to indolic compounds such as the phytoalexin camalexin and the glucosinolates (GLS)-breakdown compound indole-3-carbinol. By contrast, antagonistic strains were as inhibited as A. brassicicola in presence of allyl-isothiocyanates (ITC) derived from aliphatic GLS, and more inhibited by benzyl-ITC derived from aromatic GLS. However, all defense compounds could enhance the antagonistic effects of some of the isolated strains on A. brassicicola. The observed potential synergistic effects between defense compounds and seed-associated antagonistic strains emphasize the need for further studies to elucidate the molecular bases of the interactions. A better understanding of the interactions between host plants, pathogens and fungal endophytes is also needed to develop sustainable biocontrol strategies.

Antagonism of rhizosphere Trichoderma brevicompactum DTN19 against the pathogenic fungi causing corm rot in saffron (Crocus sativus L.) in vitro.

Corm rot in saffron (Crocus sativus L.) significantly impacts yield and quality. Non-toxic fungi, particularly Trichoderma species, are valuable for biological control due to their production of diverse and biologically active secondary metabolites. This study aimed to isolate an effective antagonistic fungus against the pathogenic fungi causing corm rot in saffron. Four pathogenic fungi (Fusarium oxysporum, Fusarium solani, Penicillium citreosulfuratum, and Penicillium citrinum) were isolated from diseased saffron bulbs in Chongming. Initial screening through dual culture with these pathogens re-screening from rhizosphere soil samples of C. sativus based on its inhibitory effects through volatile, nonvolatile, and fermentation broth metabolites. The inhibitory effect of biocontrol fungi on pathogenic fungi in vitro was evaluated by morphological observation and molecular biology methods. Antagonistic fungi were identified as Trichoderma brevicompactum DTN19. F. oxysporum was identified as the most severe pathogen. SEM (scanning electron microscope) and TEM (transmission electron microscope) observations revealed that T. brevicompactum DTN19 significantly inhibited the growth and development of F. oxysporum mycelium, disrupting its physiological structure and spore formation. Additionally, T. brevicompactum DTN19 demonstrated nitrogen fixation and production of cellulase, IAA (Indole acetic acid), and siderophores. Whole-genome sequencing of strain DTN19 revealed genes encoding protease, cellulase, chitinase, β-glucosidase, siderophore, nitrogen cycle, and sulfate transporter-related proteins. T. brevicompactum DTN19 may inhibit the propagation of pathogenic fungi by destroying their cell walls or producing antibiotics. It can also produce IAA and iron carriers, which have the potential to promote plant growth. Overall, T. brevicompactum DTN19 showed the development prospect of biological agents.

Biological control of cucumber (Cucumus sativus L.) and ridge gourd [Luffa detangula L. (Roxb.)] damping-off by fungal and bacterial antagonist

Biological control of cucumber (Cucumus sativus L.) and ridge gourd [Luffa detangula L. (Roxb.)] damping-off by fungal and bacterial antagonist

Efficacy of slow sand filtration enriched with Trichoderma atroviride in the control of Rhizoctonia solani in soilless culture

Soilless cultivation is increasingly common, but the nutrient-rich drainage from substrate cultivation is often discarded. However, drainage can be safely reused if previously disinfected. Slow sand filtration (SSF) is a low-cost, ecological, and effective method for water disinfection, primarily through biological control. Enhancing SSF with antagonistic microorganisms is not well-studied. Additionally, SSF has not been tested to control Rhizoctonia solani, a phytopathogen that can be spread by irrigation water. Therefore, the objective of his work was to test the efficacy of a slow sand filter improved through the inoculation of the antagonistic fungus Trichoderma atroviride, evaluating its suppression capacity against Rhizoctonia solani spread by the irrigation water in a closed substrate cultivation of cucumber (Cucumis sativus). Five experiments were conducted, testing the presence and absence of a sand filter, T. atroviride, and R. solani in each trial. Median disease severity was expressed on a scale of 1–5. The improved SSF increased disease control percentage by 49% compared to SSF alone and by 86% compared to no disease control method. In some experiments, SSF with T. atroviride totally controlled R. solani. The results confirm that biologically enhanced SSF with T. atroviride can effectively disinfect drainage in closed soilless cultivation systems infected with R. solani.

Isolation of Antagonistic Endophytic Fungi from Postharvest Chestnuts and Their Biocontrol on Host Fungal Pathogens.

In this study, antagonistic endophytic fungi were isolated from postharvest chestnut fruits; endophytic antagonistic fungi and their combination of inhibitory effects on the fungal pathogen Neofusicoccum parvum were evaluated. A total of 612 endophytic fungi were isolated from 300 healthy chestnut kernels, and 6 strains out of them including NS-3, NS-11, NS-38, NS-43, NS-56, and NS-58 were confirmed as antagonistic endophytic fungi against Neofusicoccum parvum; these were separately identified as Penicillium chermesinum, Penicillium italicum, Penicillium decaturense, Penicillium oxalicum, Talarmyces siamensis, and Penicillium guanacastense. Some mixed antagonistic endophytic fungi, such as NS-3-38, NS-11-38, NS-43-56, and NS-56-58-38, exhibited a much stronger antifungal activity against N. parvum than that applied individually. Among them, the mixture of NS-3-38 showed the highest antifungal activity, and the inhibition rate was up to 86.67%. The fermentation broth of NS-3, NS-38, and their combinations exhibited an obvious antifungal activity against N. parvum, and the ethyl acetate phase extract of NS-3-38 had the strongest antifungal activity, for which the inhibitory rate was up to 90.19%. The NS-3-38 fermentation broth combined with a chitosan coating significantly reduced N. parvum incidence in chestnuts from 100% to 19%. Furthermore, the fruit decay and weight loss of chestnuts during storage were significantly decreased by the NS-3-38 fermentation broth mixture along with a chitosan coating. Therefore, a mixture of P. chermesinum and P. decaturense could be used as a potential complex biocontrol agent to control postharvest fruit decay in chestnuts.

Modulation of Growth and Mycotoxigenic Potential of Pineapple Fruitlet Core Rot Pathogens during In Vitro Interactions.

Pineapple Fruitlet Core Rot (FCR) is a fungal disease characterized by a multi-pathogen pathosystem. Recently, Fusarium proliferatum, Fusarium oxysporum, and Talaromyces stollii joined the set of FCR pathogens until then exclusively attributed to Fusarium ananatum. The particularity of FCR relies on the presence of healthy and diseased fruitlets within the same infructescence. The mycobiomes associated with these two types of tissues suggested that disease occurrence might be triggered by or linked to an ecological chemical communication-promoting pathogen(s) development within the fungal community. Interactions between the four recently identified pathogens were deciphered by in vitro pairwise co-culture bioassays. Both fungal growth and mycotoxin production patterns were monitored for 10 days. Results evidenced that Talaromyces stollii was the main fungal antagonist of Fusarium species, reducing by 22% the growth of Fusarium proliferatum. A collapse of beauvericin content was observed when FCR pathogens were cross-challenged while fumonisin concentrations were increased by up to 7-fold. Antagonism between Fusarium species and Talaromyces stollii was supported by the diffusion of a red pigmentation and droplets of red exudate at the mycelium surface. This study revealed that secondary metabolites could shape the fungal pathogenic community of a pineapple fruitlet and contribute to virulence promoting FCR establishment.

Sclerotinia sclerotiorum on bean and potato in Sinaloa: Etiology, epidemiology and alternatives for management

White mold (Sclerotinia sclerotiorum) is the main disease of bean and potato in Sinaloa. In the present review, the symptoms and signs of the disease as well as cultural and morphological characteristics of the teleomorph of the pathogen, its ecology and the epidemiology of the disease are addressed. The implementation of a prediction system which includes the carpogenic germination of the sclerotia and the phenology of both bean and potato for the management of the disease is described. This system considers soil temperature ranging from 13 to 19 °C a at depth of 2.5 cm in the soil and the flowering stage in both bean and potato to do the first spray application of synthetic fungicide to prevent the disease. In vitro studies indicated that Trichoderma harzianum, T. viride and T. atroviride reduced mycelial growth rate of S. sclerotiorum. The same antagonistic species exerted control of white mold under field conditions, where an increment of 40% of yield was observed in the treated plots, with respect to those treated with fungicide fluazinam. Future lines of research focusing on the ecology of the pathogen and management of the disease including the antagonistic fungi in the prediction system are suggested.

Evaluating the efficacy of microbial antagonists in inducing resistance, promoting growth, and providing biological control against powdery mildew in wheat.

This study evaluates the biocontrol efficacy of three bacterial strains (Pseudomonas fluorescens DTPF-3, Bacillus amyloliquefaciens DTBA-11, and Bacillus subtilis DTBS-5) and two fungal strains (Trichoderma harzianum Pusa-5SD and Aspergillus niger An-27) antagonists, along with their combinations at varying doses (5.0, 7.5, and 10.0 g/kg of seeds), against wheat powdery mildew. The most effective dose (10 g/kg seeds) was further analyzed for its impact on induced resistance and plant growth promotion under greenhouse conditions. The study measured defense enzyme activities, biochemical changes, and post-infection plant growth metrics. All tested microbial antagonists at 10 g/kg significantly reduced PM severity, with B. subtilis strain DTBS-5 outperforming others in reducing PM severity and achieving the highest biocontrol efficacy. It was followed by B. amyloliquefaciens strain DTBA-11 and P. fluorescens strain DTPF-3, with the fungal antagonists showing no significant effect. Wheat crops treated with B. subtilis strain DTBS-5 exhibited substantial increases in defense-related enzyme activities and biochemicals, suggesting an induced resistance mechanism. The study found a 45% increase in peroxidase (POD) activity, a 50% increase in catalase (CAT) activity, a 30% increase in phenolic content, and a 25% increase in soluble protein content in the wheat plants treated with microbial antagonists. The study highlights the effectiveness of microbial antagonists, particularly B. subtilis strain DTBS-5, in managing wheat PM through biocontrol, induced resistance, and enhanced plant growth, offering a sustainable alternative to chemical treatments.

Potential Antagonists Trichoderma viride as Biofungicide, Plant Spacing, and Agricultural Lime Application to Suppress Anthracnose on Chili

Anthracnose caused by Colletotrichum capsici and C. gloesporium on chili is a disease that can reduce chili yields up to 80%. Control with fungicide has not been able to provide maximum results, because Colletotrichum can spread due to splashing of water, especially in the rainy season. The use of antagonistic fungi against Colletotrichum spp. has been widely published but is still limited to the laboratory and greenhouse scale, while field conditions are unpredictable. This study aims to identify the potency of Trichoderma viride that can be used as a biofungicide to control anthracnose in chili and to determine aspects of agronomic that can reduce the risk of anthracnose in chili. Samples of infected plants of stems, leaves, and fruits were collected from experimental farm of Bogor Agricultural Development Polytechnic. The experiment was conducted using Randomized Complete Design and Randomized Complete Block Design. The percentage of disease intensity of the fungus C capsici and the intensity of anthracnose in chili both under screen house and open fields. While testing the effect of cultivation aspects using different types of fertilizer on plant height, fruit weight, number of fruits, and the percentage of disease intensity of Colletotrichum spp. were analyzed. The results of this study shown that four isolates of fungi have been identified such as Penicillium sp., Aspergillus flavus, T. viride, and C. capsici. In vitro analysis shown the ability of T. viride to suppress the growth of the C. capsici up to 71%. The fungus T. viride with a density of 7×106 CFU/mL can suppress the development of anthracnose by 59 to 87% under screen house conditions. However, under field conditions, the fungus T. viride was not able to suppress the development of anthracnose. Agronomic aspects such as plant height, number of fruits and production, and productivity of chili were not significantly effect on anthracnose.

Repeated horizontal acquisition of lagriamide-producing symbionts in Lagriinae beetles.

Microbial symbionts associate with multicellular organisms on a continuum from facultative associations to mutual codependency. In some of the oldest intracellular symbioses there is exclusive vertical symbiont transmission, and co-diversification of symbiotic partners over millions of years. Such symbionts often undergo genome reduction due to low effective population sizes, frequent population bottlenecks, and reduced purifying selection. Here, we describe multiple independent acquisition events of closely related defensive symbionts followed by genome erosion in a group of Lagriinae beetles. Previous work in Lagria villosa revealed the dominant genome-eroded symbiont of the genus Burkholderia produces the antifungal compound lagriamide and protects the beetle's eggs and larvae from antagonistic fungi. Here, we use metagenomics to assemble 11 additional genomes of lagriamide-producing symbionts from seven different host species within Lagriinae from five countries, to unravel the evolutionary history of this symbiotic relationship. In each host species, we detected one dominant genome-eroded Burkholderia symbiont encoding the lagriamide biosynthetic gene cluster (BGC). Surprisingly, however, we did not find evidence for host-symbiont co-diversification, or for a monophyly of the lagriamide-producing symbionts. Instead, our analyses support at least four independent acquisition events of lagriamide-encoding symbionts and subsequent genome erosion in each of these lineages. By contrast, a clade of plant-associated relatives retained large genomes but secondarily lost the lagriamide BGC. In conclusion, our results reveal a dynamic evolutionary history with multiple independent symbiont acquisitions characterized by high degree of specificity. They highlight the importance of the specialized metabolite lagriamide for the establishment and maintenance of this defensive symbiosis.

Using Fungal and Bacterial Bioagent Formula Antagonists to Combat Fusarium Oxysporum f. sp. Lycopersici Under Greenhouse Conditions

Objective: This study aimed to test fungal and bacterial bioagents as formula antagonists of Fusarium oxysporum f. sp. lycopersici under greenhouse conditions. Methods: The fungal and bacterial formulations' shelf life under different temperatures as well as under growth chamber and greenhouse conditions, as well as their effects on biochemical alterations involved in the induction of plant defense against the causative pathogen were investigated. Results: In-vitro antagonist screening of bacterial and fungal isolates on radial growth, reduction and inhibition percentages revealed that T. harzianum exhibited 45.6% of inhibition followed by B. pumilus with 36.7%. Among the fungal and bacterial bio-agents, the highest effect on disease incidence and efficiency against pathogenic fungus under greenhouse conditions was B. pumilus 27 and 69%, respectively followed by T. harzianum 33 and 62% when applied before pathogen inoculation. Under greenhouse conditions, the effects of bio-fungicides also affected defense enzymes like peroxidase and polyphenol oxidase. The shelf life of the wettable powder formulation of bio-agents under different temperature was very important factor and established that the most suitable temperature for long term storage is 25 ºC for both B. pumilus and T. harzianum. Conclusion: Target application of disease control techniques in tomato plants demonstrated the efficacy of B. pumilus and T. harzianum in reducing Fusarium wilt. These results pave the way for the development of bio-agents that can replace fungicides in agriculture, offering a practical substitute.

Potensi Cendawan Antagonis Trichoderma Viride Isolat Bogor sebagai Agensi Pengendalian Hayati Penyakit Antraknosa Tanaman Cabai Merah

Anthracnose disease caused by Colletottrichum capsici on chili plants that can damage yields by up to 80%. Control with fungicides has not been able to provide maximum results, because the fungus can move due to water splashes, especially in the rainy season. The use of antagonistic fungi against Colletotrichum capsici. has been widely published but is still limited to laboratory and greenhouse scales. This study aims to analyze the potential of Bogor isolate Trichoderma viride antagonist fungus against the fungus C. capsici through in-vitro study in the laboratory, screen houses, and field conditions. The experiment was structured using Complete Randomized Design (CRD) with parameters that measured respectively the antagonistic ability, and the percentage of attack by C. capsici and the severity of anthracnose disease on chili plants were both tested in screen house condition. Bogor Isolate T. viride has potential as a biological control agent for chili plants. This is proven by the ability to suppress the growth of C. capsici by 71% in vitro. The use of the fungus T. viride with a concentration of 7x106 conidia/ml (full strength) can suppress the development of anthracnose by 59 to 87% under screen house conditions. In other words, the pathogenicity of capsici in red chili plants shows a severity level of 13 to 41%.

Chemical Fungicides and Antagonists as Potential Treatments for Ganoderma lucidum-Associated Basal Stem Rot in Mandarin Trees

Ganoderma lucidum causes basal stem rot disease in mandarin trees, resulting in a variety of symptoms including dieback, foliage discoloration, an unhealthy appearance and eventual tree declines or death. Prior to field application, it is imperative to assess the efficacy of newer molecules and possible potential antagonists through In vitro testing. In this study, ten chemical fungicides and four antagonists were evaluated for their effectiveness against G. lucidum using the poison food method and dual culture technique, respectively. Among the chemical fungicides tested, Copper oxychloride 50% WP (@3g/l), Fluxapyroxad 167 G/L + Pyraclostrobin 333 G/L SC (@0.6 g/l), and Metiram 55% + Pyroclostribin 5% WG (@1g/l) demonstrated the highest effectiveness, entirely suppressing (100%) pathogen growth. In the dual culture technique, the fungal antagonists Trichoderma harzianum (79.63%) and Trichoderma asperellum (77.57%) exhibited superior effectiveness compared to Pseudomonas fluorescence and Bacillus subtilis against G. lucidum. These findings highlight the efficacy of chemical fungicides and antagonists in treating G. lucidum-induced basal stem rot in mandarin trees.