Synthetic Fungicides Research Articles

Efficacy of Lemon Myrtle Essential Oil as a Bio-Fungicide in Inhibiting Citrus Green Mould.

The effectiveness of lemon myrtle (LM) (Backhousia citriodora) essential oil (EO) was investigated to combat Penicillium digitatum by in vitro agar diffusion and vapour assay and in artificially infected oranges. The main constituent of LM EO was revealed as citral when analysed in gas chromatography-mass spectrometry. Pure citral was also included in the experiment for comparison. The in vitro fungal growth was significantly inhibited by LM EO at 1, 2, 3, 4 and 5 μL per disc while complete growth inhibition by both the pure citral and LM EO occurred at 4 and 5 μL per disc. Inoculated fruits treated by dipping in 1000 μL L-1 LM EO solutions for 5, 10, 15, 30 and 120 s showed significantly lower fungal wounds compared to control. While longer dipping times led to some rind injuries, fruits with a 5 and 10 s dip were found free from any injury. The evaluation after dipping and storage confirmed that the fruits maintained the sensory attributes and were not compromised by the incorporation of the essential oil. The results of this study indicate that LM EO can be a promising alternative to synthetic fungicides for preserving the quality of citrus fruits during storage.

Effects of field spray of selected botanicals on management of Phytophthora colocasiae induced taro cultivars cormels myco storage rots in Nsukka, Southeastern Nigeria

Anti-myco pathogenic effect of field spray of botanical extract from neem (Azadirachta indica), Eucalyptus (Eucalyptus spp) and siam weed (Chromolaena odorata) against Phytophthora leaf blight disease of taro cultivars at weekly spray intervals were determined in vitro on growth of post-harvest myco pathogens of stored taro cultivars cormels. The storage, isolation and identification of the isolates were done at the Department of Crop Science Taro barn and Plant Pathology Unit, University of Nigeria, Nsukka. Results showed that the following fungal isolates were identified; Botryodiplodia theobromae, Sclerotium rolfsii, Aspergillus niger, Fusarium solani, Rhizopus stolonifer, Penicillium digitalium and Trichoderma viride with Botryodiplodia theohromae being the most occurred among the pathogens in all taro stored samples. The inhibitory potential of extracts varied with cultivars and pathogens. The percentage (%) of occurrence of isolates was highest in the coco India cultivar with no treatment, while the least was in purple green taro/Nachi cultivar with Ridomil gold treated samples. However, all botanicals proved effective in reducing post-harvest rot organisms compared to control in all samples. The fungitoxic potential of field sprays of botanicals against myco-rot pathogens of stored taro cultivars cormels is highly recommended to farmers as alternative natural fungicides to common potential health danger synthetic commercial fungicides.

Phytochemicals reduced growth, sporulation and conidial dimensions of Fusarium verticillioides, cause of fumonisin contamination in maize grains

The objective of the study was to evaluate the effectiveness of methanolic extracts of plants against radial growth and spore dimensions of Fusarium verticillioides. Leaf extracts of 25 plants were tested against the fungus. Of which, thirteen extracts were potent against the fungus and evaluated using food poising technique. Growth was evaluated on PDA medium amended with the extracts at 5 mg ml–1. Control treatments included plates without (negative) extracts and with synthetic (positive) fungicide. Spore dimension was determined using PDB. The results showed T. vulgaris extract completely inhibited mycelial growth of the fungus as equivalent as the fungicide. Similarly, G. parviflora, C. citratus, R. officinalis, R. chalepensis, and Agave sp. also recorded growth reductions ranging from 71.04 to 81.35 % at day seven. In addition, extracts of Agave sp., C. citratus and T. vulgaris did not support sporulation. Overall, the results indicate that T. vulgaris extracts could be safe source of bioactive chemicals to control F. verticillioides.

Antifungal and toxicological evaluation of the alkaloids fraction from Neltuma nigra leaves

The use of synthetic fungicides for control soybean crop diseases has been cuestionated because of its impacts on human health and the environment. This work evaluated the composition, antifungal activity and toxicity of the alkaloids fraction obtained from Neltuma nigra leaves and compared its effect with the fungicide difenoconazole on Sclerotium rolfsii, Cercospora kikuchii, and C. sojina. Alkaloids fraction was extracted from leaves of N. nigra and its composition was analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). The antifungal effect was recorded by measuring diameters of halos of inhibition of the growth of the different evaluated fungis. The toxicity of the alkaloids fraction was carried out using the method of Caenorhabditis elegans toxicity test. The extracted alkaloids fraction contained the alkaloids tryptamine (63.9%), tetrahydroxyharman (13.8%), phenethylamine (11.1%), cassine (10.4%), and N-formylphenylethylamine (0.8%). The alkaloids fraction was as effective against S. rolfsii as on the Cercospora strains, with minimum inhibitory doses of 25.0 μg disc-1 and inhibitory halos in the range of 8.5-13.0 mm, while difenoconazole had no effect on S. rolfsii. The toxicity of the alkaloid fraction (30.4-68.8 mg L-1) and difenoconazole (0.1-2.8 mg L-1) was tested on the reproduction, body length, and fertility of C. elegans. The fraction reduced the reproductive rate by 28.8-72.4% whereas difenoconazole did it from 12.2% to complete suppression. Neither of them affected the fertility of C. elegans. These findings suggest that the alkaloids fraction of N. nigra leaves is less toxic than difenoconazole and is a promising botanical fungicide against pathogenic soybean fungi.

Effect of Postharvest Treatments on Physiological, Chemical, Microbial and Sensory Qualities of Fruits of Papaya Variety Surya

Background: Papaya is a climacteric fruit which is highly perishable due to rapid ripening and softening and susceptibility to biotic or abiotic stresses, resulting in large losses during storage. Traditionally, people resort to the application of synthetic chemical fungicides on to the crop plant and to the fruits during storage, to control the anthracnose caused by the fungus Colletotrichum gloeosporioides on fruits. But their repeated use has caused resistance in microorganisms and toxicity for humans. Hence, nowadays there has been increasing interest in using natural alternatives instead of chemical treatment. Methods: Fruits of papaya variety Surya collected at fully mature green stage were subjected to different postharvest management practices namely precooling, surface sanitization, treatment with chitosan and were packaged in corrugated fibre board boxes and stored till the end of shelf life under ambient condition. Untreated fruits (control) were also used in the study. Result: Fruits coated with chitosan (1%) registered an improved shelf life of 6.33 days as against 4.33 days in control in ambient storage and it further improved the sensory score for all the organoleptic parameters, after six days of storage. 1% chitosan coating also reported significantly lowest physiological loss in weight (3.51 %), ion leakage (60.47%), total soluble solids (12.13 °Brix), total carotenoids (2.34 mg 100g-1), total sugar (7.26%) and reducing sugar (6.34%) and least disease index (16.67%), bacterial count (22.33 cfu/ml × 106) and fungal count (7.33 cfu/ml × 103) after three days of storage when compared with control.

Systemic biochemical changes in pepper (Capsicum annuum L.) against Rhizoctonia solani by kale (Brassica oleracea var. acephala L.) green manure application

BackgroundIn the search for new alternatives to avoid the problems associated with the use of synthetic chemical fungicides in agriculture, the use of green manure (GrM) could help combat fungal diseases of crops, such as those produced by the necrotrophic pathogen Rhizoctonia solani. In the case of the use of Brassica tissues as GrM, it could have an elicitor capacity for systemic plant resistance.ResultsWe used kale leaves as a GrM and applied it to pepper plants infected with R. solani. The application of freeze-dried kale tissues to the roots of pepper plants produced a systemic activation of foliar defences via the salicylic acid (SA) and ethylene (ET) pathways, significantly reducing pathogen damage. In addition, this systemic response led to the accumulation of secondary defence metabolites, such as pipecolic acid, hydroxycoumarin and gluconic acid, in leaves. Remarkably, pepper plants treated with lyophilised kale GrM accumulated glucosinolates when infected with R. solani. We also confirmed that autoclaving removed part of the glucobrassicin (85%) and sinigrin (19%) content of the kale tissues.ConclusionsGrM kale tissues can activate systemic defences in bell pepper against foliar pathogens through SA/ET hormonal pathways, accumulating secondary defence metabolites.

GC–MS, quantum mechanics calculation and the antifungal activity of river red gum essential oil when applied to four natural textiles

The most important uses of old fabrics include clothing, mummification, and bookbinding. However, because they are predominantly constructed of natural materials, they are particularly susceptible to physical and chemical deterioration brought on by fungi. The treatments that are typically used to preserve old textiles focus on the use of synthetic fungicides, which have the potential to be dangerous for both human health and the environment. Essential oils (EOs), which are safe for the environment and have no negative effects on human health, have been widely advocated as an alternative to conventional antifungals. Four natural fabrics—linen, cotton, wool, and silk—were utilized in the current work. The extracted EO from leaves of river red gum (Eucalyptus camaldulensis Dehnh.) were prepared at 125, 250, and 500 µL/L. Aspergillus flavus, Fusarium culmorum and Aspergillus niger were inoculated separately into the treated four fabrics with the EO at concentrations of 125, 250, and 500 µL/L or the main compounds (spathulenol and eucalyptol) at the concentrations of 6, 12, 25, and 50 µL/L and were then compared to the un-treated samples. GC–MS was used to analyze the EO chemical composition, while visual observations and scanning electron microscopic (SEM) were used to study the fungal growth inhibition. Spathulenol (26.56%), eucalyptol (14.91%), and p-cymene (12.40%) were the principal chemical components found in E. camaldulensis EO by GC–MS. Spathulenol molecule displayed the highest electrostatic potential (ESP) compared with the other primary compound, as calculated by quantum mechanics. In the untreated textile samples, SEM analysis revealed substantial proliferation of hyphae from A. flavus, F. culmorum, and A. niger. The fungal growth was completely inhibited at a concentration of 500 µL/L from the EO. Both eucalyptol and spathulenol completely inhibited the formation of the fungal spores at a concentration of 50 µL/L, although eucalyptol was more effective than spathulenol across the board for all four textiles. The results support E. camaldulensis EO functionalized textiles as an effective active antifungal agent.

Integration of Sclerotinia sclerotiorum-Targeted Biofungicides Coniothyrium minitans and Bacillus amyloliquefaciens into Season-Long Soybean Pest Management Practices in Indiana

Two biofungicides, Coniothyrium minitans and Bacillus amyloliquefaciens, are commercially available and have been shown to limit or suppress Sclerotinia sclerotiorum in soybean. S. sclerotiorum is a soilborne pathogen of soybean that can cause significant yield losses under cool and wet environmental conditions. Integrated soybean pest management practices can include the application of herbicides, fungicides, and insecticides at various times during the growing season to minimize yield losses. However, limited information is available regarding how these biofungicides can be successfully incorporated into a soybean-integrated pest management program. To assess the sensitivity of C. minitans and B. amyloliquefaciens biological activity on S. sclerotiorum to pesticides commonly used in soybean-production systems, a poison plate assay and soil plate and growth chamber experiments were conducted. In the poison plate assay, C. minitans was most sensitive to the preemergence herbicide flumioxazin and the synthetic fungicides boscalid and fluazinam, whereas B. amyloliquefaciens was sensitive only to the synthetic fungicide fluazinam. In the soil plate assay, the mycoparasitic activity of C. minitans on S. sclerotiorum was sensitive to flumioxazin, metribuzin, glyphosate, picoxystrobin, and boscalid. In the controlled environment experiments, none of the pesticides tested decreased the efficacy of B. amyloliquefaciens. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Control of Brown Rot Produced by Monilinia fructicola in Peaches Using a Full-Spectrum Extract of Zuccagnia punctata Cav.

Brown rot of stone fruit, caused by Monilinia spp., is one of the most important diseases worldwide, causing significant production losses. Currently, the standard practices for controlling this infection consist of repetitive use of synthetic fungicides. The global tendency encourages the demand for high-quality food products harmless to health and the environment, leading to a reduction in the use of these types of substances. Zuccagnia punctata (Fabaceae) is a perennial shrub extensively used for the treatment of fungal and bacterial infections in Argentinean traditional medicine. In this study, we isolated and characterized (morphologically and molecularly) a pathogenic and virulent strain of Monilinia fructicola, which is the most hostile species of the genus. Consequently, we explored the in vitro antifungal activity of the ethanolic extract of Z. punctata against this phytopathogen. The chalcones 2′,4′-dihydroxy-3′-methoxychalcone and 2′,4′-dihydroxychalcone were isolated from the extract and evaluated against M. fructicola demonstrating that they were responsible for this activity. To promote full-spectrum extract rather than pure compounds, we performed ex-vivo assays using fresh peaches inoculated with the pathogen, and then treated by immersion in an extract solution of 250 µg/mL concentration. Treatment with Z. punctata extract did not show a statistically significant difference from commercial fungicides in the control of fruit rot. In addition, Huh7 cell cytotoxicity evaluation showed that Z. punctata extract was less cytotoxic than commercial fungicides at the assayed concentrations. Based on our research, this plant extract could potentially offer a safer alternative to commercial fungicides for treating peach brown rot.

The antifungal mechanism of Monarda citriodora essential oil, hexanal and their combined vapours on Aspergillus foetidus

BackgroundThe increased reliance on synthetic fungicides for managing postharvest pathogens resulted in the rise of fungicide-resistant pathogen strains. Previous studies have reported essential oils (EOs) as a promising alternative to synthetic fungicides. However, higher concentrations are required for their practical application, which can alter the taste profile of the stored produce. Synergistic combinations of EO volatiles can reduce the active concentrations, thereby mitigating undesirable taste profile changes. However, very few studies have emphasised the changes in the mode of action of EO volatiles when applied as a synergistic combination. This study aimed to decipher the mode of action of Monarda citriodora essential oil (MEO) and hexanal vapour combination (M + H) against the newly identified postharvest pathogen of apple Aspergillus foetidus. ResultsThe M + H vapour treatment synergistically inhibited the spore germination of A. foetidus at the concentration of 144.23 μL L−1 air (MEO) and 96.15 μL L−1 air (hexanal). Propidium Iodide staining and ergosterol content analysis revealed that vapours compromised the plasma membrane integrity. Hence, there was an extracellular leakage of cytoplasmic components, reduced extracellular pH and increased conductivity. Furthermore, calcofluor white staining showed reduced fluorescence intensity, indicating a compromised cell wall. Reduced chitin content in the cell walls of vapour treated mycelia authenticated the results. 2′,7′-Dichlorofluorescin diacetate (DCFDA) staining revealed the generation and accumulation of Reactive Oxygen Species (ROS) within the vapour treated mycelia. ConclusionThe accumulated ROS interferes with ergosterol and chitin synthesis leading to the collapse of the plasma membrane and cell wall; consequently, extracellular leakage occurs.

Efficacy of Biocontrol Agents Coniothyrium minitans and Bacillus amyloliquefaciens for Managing Sclerotinia sclerotiorum in Indiana Soybean

Sclerotinia sclerotiorum is a soilborne pathogen of soybean that causes Sclerotinia stem rot, also called white mold. Sclerotinia stem rot can cause significant yield losses under cool and wet environmental conditions. Two biofungicides, Coniothyrium minitans and Bacillus amyloliquefaciens, are currently available and labeled to limit or suppress S. sclerotiorum in soybean. These biofungicides can be applied in place of synthetic foliar fungicides to provide an alternative mode of action for the control of Sclerotinia stem rot. However, limited information is available regarding the efficacy of C. minitans and B. amyloliquefaciens as biocontrol agents of S. sclerotiorum in soybean. To assess the effectiveness of C. minitans and B. amyloliquefaciens as biocontrol agents of S. sclerotiorum, dual culture and soil plate assays were conducted, along with experiments in the growth chamber and field. Degradation of sclerotia following treatment with C. minitans in the soil plate assay confirmed that the primary mode of action is mycoparasitism. In the growth chamber, B. amyloliquefaciens at 14.03 liters/ha applied using the dip method significantly reduced Sclerotinia stem rot lesion length over the nontreated control and resulted in the lowest lesion area under the disease progress curve. When B. amyloliquefaciens and C. minitans were applied in the field, no differences were observed between treatments for soybean moisture, test weight, or yield in Indiana. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Prospects of Bacillus amyloliquefaciens (MZ945930) Mediated Enhancement of Capsicum annuum L. Plants Under Stress of Alternaria alternata in Terms of Physiological Traits, Thiol Content, Antioxidant Defense, and Phytohormones

Plants encounter many biotic entities, such as fungi, bacteria, and nematodes, which induce biotic stress that disrupts normal metabolism and limits the growth and productivity of plants. Currently, the use of plant growth-promoting bacterial endophytes instead of synthetic fungicides is intriguingly eco-friendly. An in vitro and in vivo antagonistic approach using Bacillus amyloliquefaciens RaSh1 was used to mimic the pathogenic effect of Alternaria alternata. The results showed that B. amyloliquefaciens significantly inhibited pathogenic fungal growth in vitro. Further, Capsicum annuum L. (pepper plants) were grown and subjected to inoculation with B. amyloliquefaciens and infected with A. alternata, and then the growth attributes, photosynthetic pigments, physio-biochemical parameters, and the level of endogenous phytohormones were assessed. Under the pathogen attack, the main responses, such as plant length, total fresh and dry weights, total chlorophylls, and pigments, were reduced, accompanied by increases in H2O2. As well, infection of pepper with A. alternata caused downregulation in the plant hormonal system by significantly decreasing gibberellins, indole-3-acetic acid, abscisic acid, as well as cytokinin concentrations. Although, with B. amyloliquefaciens application, an enhancement in growth, photosynthetic pigments, proline, thiol content, phenylalanine ammonia-lyase, and peroxidase in pepper plant leaves appeared while the content of H2O2 decreased. Endogenous phytohormones were found to be upregulated in B. amyloliquefaciens-inoculated and diseased plants. The current study found that B. amyloliquefaciens RaSh1 rescued pepper plant growth by modulating antioxidant defense and regulating hormones, and could be used to control A. alternata in an environmentally friendly manner while maintaining sustainable agriculture and food security.

In vitro and in vivo efficacy of Larrea divaricata extract for the management of Phytophthora palmivora in olive trees

Phytophthora palmivora is a ubiquitous pathogen responsible for “dry branch” disease, causing significant economic losses in olive trees. Synthetic chemical fungicides are currently used for the control of P. palmivora. The general concern about the negative consequences of using synthetic products prioritizes the search for eco-friendly alternatives. In this context, plant extracts have emerged as an interesting and promising alternative for crop protection. This work studies the inhibitory activity of Larrea divaricata extract on P. palmivora mycelial growth, sporangium and zoospore production. The extract showed fungicidal activity against P. palmivora mycelial growth at concentrations over 150 mg mL-1. Specifically, the extract at 50 mg mL-1 completely suppressed the production of P. palmivora sporangia and zoospores. The alkaloid piperine in L. divaricata extract showed antimicrobial activity against P. palmivora mycelial growth. Extract effectiveness was also evaluated on olive trees in a greenhouse, showing 63% of disease reduction. These results support the use of L. divaricata extract as another environmentally friendly tool to be included in an integrated disease management program for dry branch disease caused by P. palmivora. Highlights: L. divaricata extract showed an effective antimicrobial activity against P. palmivora. Piperine was identified in the divaricata extract by HPLC/MWD. The alkaloid piperine in divaricata extract showed antimicrobial activity on the mycelial growth of P. palmivora. L. divaricata extract could be included in an integrated management programme for dry branch disease caused by P. palmivora.

Plant extracts as biocontrol agents against Aspergillus carbonarius growth and ochratoxin A production in grapes

Aspergillus carbonarius (Bainier) Thom. is an important pathogen and ochratoxin A (OTA) producer in grapes that can be controlled by adopting sustainable approaches. Here we evaluate the application of natural plant extracts as an alternative to synthetic fungicides to reduce OTA contamination and to prevent infection of grapes by two isolates of A. carbonarius. In a preliminary screening, natural extracts of chestnut flower, cistus, eucalyptus, fennel, and orange peel were evaluated for their antifungal and anti-mycotoxigenic efficiency in a grape-based medium at concentrations of 10 and 20 mg/mL. Cistus and orange peel extracts demonstrated the best antifungal activity at both concentrations. Although the eucalyptus extract demonstrated no significant effect on Aspergillus vegetative growth, it significantly reduced OTA by up to 85.75 % at 10 mg/mL compared to the control. Chestnut flower, cistus, eucalyptus, and orange peel extracts were then tested at the lowest concentration (10 mg/mL) for their antifungal activity in artificially inoculated grape berries. The cistus and orange peel extracts demonstrated the greatest antifungal activity and significantly reduced mold symptoms in grapes. Moreover, all tested natural extracts were able to reduce OTA content in grape berries (17.7 ± 8.3 % - 82.3 ± 3.85 % inhibition), although not always significantly. Eucalyptus extract was particularly efficient, inhibiting OTA production by both strains of A. carbonarius by up to >80 % with no effects on fungal growth. The use of natural eucalyptus extract represents a feasible strategy to reduce OTA formation without disrupting fungal growth, apparently maintaining the natural microbial balance, while cistus and orange peel extracts appear promising as inhibitors of A. carbonarius mycelial growth. Our findings suggest that plant extracts may be useful sources of bioactive chemicals for preventing A. carbonarius contamination and OTA production. Nonetheless, it will be necessary to evaluate their effect on the organoleptic properties of the grapes.

Biocontrol rhizobacteria enhances growth and yield of wheat (Triticum aestivum) under field conditions against Fusarium oxysporum

ABSTRACTThe current study aimed to identify the survival of bio-control bacteria with antifungal activity against Fusarium oxysporum and assess their growth promoting activity in wheat crop field conditions. To evaluate the fungicidal activities of isolated bacteria using the dual culture method, both qualitative and quantitative bioassays were performed. Plant Growth Promoting activities such as Indole 3-Acetic Acid (IAA), phosphate solubilization, Hydrogen cyanide (HCN), and Siderophore production were assessed for three biocontrol bacterial isolates (BCB 07, BCB16, and BCB 83) out of 180 with 70% antagonistic activity against Fusarium oxysporum. Chitinase, protease, and cellulase interaction in isolates was also tested. BCB16 was selected as it had 70% antagonist activity against F. oxysporum but also had the highest PGPR (Plant Growth Promoting Rhizobacteria) traits when compared to the other two isolates. BCB16 was also tested for survival in talc powder and in wheat crop field conditions. Even after 4 months in talc powder, the survival rate remained stable. In a wheat crop field, BCB16 reduced the disease incidence of Fusarium oxysporum by 54.38%. When compared to fungus alone treatment, BCB16 increased average yield by 57% alone and 32% in challenged conditions. BCB16 was identified molecularly using the 16s rRNA gene. Bacillus amyloliquefaciens shared 97% of the deduced sequence. The sequence was submitted to genbank and assigned the accession number OM333889. Bacillus amyloliquefaciens has the potential to be used in the field as an alternative to synthetic fungicides against Fusarium oxysporum.

Leaf shredding as an alternative strategy for managing apple scab resistance to demethylation inhibitor fungicides

Within integrated apple scab control there is a strong focus on reduction of Venturia inaequalis primary inoculum. The hypothesis that leaf shredding as an orchard sanitation practice would reduce the effective population size of the fungus (resulting in lower genetic variation due to reduction in sexual offspring) was tested. Assuming the allele causing fungicide resistance is already present in the population, it will be widely distributed at the end of the season, since selection occurs when the demethylation inhibitor (DMI) fungicide was applied. For short-term disease management a reduction of inoculum size, (i.e. potential ascospore dose) is most important. In the long-term resistant isolates/genotypes would be less likely to survive the winter and/or to infect in the spring, if that inoculum (i.e. in fallen leaves) has been removed. To sustain the use of highly effective synthetic fungicides, such as the DMIs, fungicide resistance management practices have to be evaluated. Fungicide resistance, which negatively affects pathogen fitness, is hypothetically reversible, if the selection pressure by the fungicide is removed. This study quantified the effect of leaf shredding on changes in the pathogen’s flusilazole sensitivity and population genetic structure using SSR markers. Venturia inaequalis populations in orchard trials, where sanitation practices had been applied, were tested for flusilazole sensitivity in planta and in vitro. Significant shifts towards flusilazole resistance were identified in orchards with a history of DMI application without sanitation treatment, with a mean sensitivity of EC50= 0.208 ug/ml (n=49) compared to an unexposed V. inaequalis population (EC50= 0.104 ug/ml, n=55). However, the isolates from the same sanitation trial orchards, from leaf shredding treatment in combination with a fungicide spray programme, had a mean EC50 of 0.110 ug/ml (n=41), similar to an unexposed V. inaequalis population. Furthermore, V. inaequalis offspring after sanitation treatment, showed shifts in microsatellite allele frequency distribution patterns used as an indicator of sexual reproduction. This study concludes that sanitation treatments, i.e. leaf shredding, impact on fungicide sensitivity and therefore effectively contributes to fungicide resistance management.

Exploration and macroscopic characterization of microbiomes (fungi and bacteria) on anthracnose-Infected chili plants in lowlands fields of Deli Serdang North Sumatra

Anthracnose is one of the main obstacles in chili cultivation. This disease reduces chili production by 40% to 100% during the rainy season. Most techniques used to control anthracnose is using synthetic fungicides that potentially cause resistance and environmental pollution. Disease management by the microbiome of plants with antagonistic properties is an alternative biological control. The aim of the study was to explore the diversity of the microbiome (fungi and bacteria) in various tissues (rhizosphere, endosphere and phylosphere) of large red chili plants infected with anthracnose macroscopically. The object of this research was the leaves, stems, and roots of 5 months old of chili plants affected by anthracnose from two different locations of planting areas. The exploration of the microbiome of anthracnose- infected chili plants in a lowland area in Sumatera Utara in 3 DAI discovered 13 fungi and 12 bacteria, whilst 10 fungi and 11 bacteria in the second location by tissue cropping technique. Besides that, by grinding technique, resulted in 14 fungi isolates dan 13 bacteria in the first location and 16 fungi isolates and 14 bacteria in the second location. At 7 DAI, there found 130 bacteria in the first location and 146 bacteria in location 2 by grinding technique. By tissue cropping technique, there were 124 bacteria in the first location and 102 bacteria in the second location. Morphologically, fungi were identified as Fusariumsp, Aspergillus sp, Penicillum sp, Trichoderma sp, Humicola sp, Colleotetrichum sp, Idriella sp, Alternaria sp, Rhizopus sp and Curvularia sp while the bacteria obtained 9 different isolates based on the morphology of colony.

Chitosan: a complex substance with great potential for global integrated pest management and for reducing farmers’ dependence on synthetic fungicides

Chitosan: a complex substance with great potential for global integrated pest management and for reducing farmers’ dependence on synthetic fungicides

Endophytic bacteria, from the desert spurge (Euphorbia antiquorum) enhance nutrients uptake and suppress root rot in the common bean

Global agriculture has long been concerned with the management of soil-borne diseases. Owing to their occurrence under the ground surface, coupled to the soil long-lasting anatomic structures such as conidia and chlamydospores formed by their causative agents, the latter are especially tricky to diagnose, identify and effectively manage. In this study, we evaluated the fungitoxic effects and nutrient mobilising abilities of 36 endophytic bacteria derived from the "desert spurge" (Euphorbia antiquorum L.) against Fusarium solani, Fusarium oxysporum, and Macrophomina phaseolina, the principal causative agents of common bean root rot in Cameroon. The antagonistic potentials of the biocontrol agents (BCAs) were assessed using conventional direct and indirect antagonism tests. The shortlisted candidates were thereafter evaluated for their in planta suppressive effects in a climate-controlled greenhouse in a completely randomised block design layout. Bacillus amyloliquefaciens BFL2, Bacillus velezensis BE1, and Pseudomnas aeruginosa RR4 produced wide spectrum hydro-soluble antifungal metabolites, with inhibitory percentages culminating at 80.79% vis-a-vis Fusarium solani Fs4. Likewise, with reference to Fusarium oxysporum NG22, the BCAs; Unidentified LPR3+ (84.25%) and Lyncinibacillus fusiformis RR7 (90.75%) released the most harmful volatile organic metabolites (VOM). Root rot incidence (75.4%) and severity (60.54%) were dramatically reduced after seed bacterization with B. amyloliquefaciens RA37, a far better outcome compared to Carbendazin (47.29%), a synthetic fungicide. Ultimately, N, P, K, Cu, Zn, Fe, and Mn contents, as well as overall plant vigour, were fostered by some BCAs. These findings demonstrate the remarkable biocontrol abilities of B. amyloliquefaciens RA37, opening a path to a biological solution to bean root rot.

Management of Fungal Pathogens Associated with Mango Diseases using Organic Materials

Mango (Mangifera indica) is one of the most economically important tropical fruits, but it is susceptible to various fungal pathogens that cause significant yield losses and reduce fruit quality. Traditional management strategies for these fungal diseases often involve the use of synthetic fungicides, which can have adverse effects on the environment and human health. Therefore, there is a growing need to explore sustainable and organic alternatives for managing these pathogens. This study aims to evaluate the efficacy of organic materials in controlling fungal pathogens associated with mango diseases. Various organic materials of different plant extracts were tested against common fungal pathogens. The results of the study demonstrated the potential of organic materials in managing mango fungal diseases. Plant extracts derived from neem (Azadirachta indica), garlic (Allium sativum), and ginger (Zingiber officinale) exhibited strong antifungal activity against the tested pathogens. Overall, the findings of this study suggest that organic materials can be effective tools for managing fungal pathogens associated with mango diseases. Incorporating these organic management strategies into mango production systems can contribute to sustainable agriculture practices, reduce chemical inputs, and promote the production of high-quality, disease-free mangoes.