Search

The investigation of natural alternatives to conventional fungicides is of imminent need. Mosiera bullata (Britton & P. Wilson) Bisse is a Cuban endemic plant species belonging to the Myrtaceae family. The objective of the present study was to perform a bioassay-guided fractionation to explore the potential of extracts and fractions from M. bullata leaves against a panel of fungal plant pathogens. The M. bullata total extract was confirmed to have good antifungal activity against R. oryzae (IC50 = 4.86 µg/mL) and moderate activity against F. oxysporum (IC50 = 352.40 µg/mL) and F. solani (IC50 = 427.38 µg/mL) and fungicidal effect against R. oryzae. Five compounds belonging to the class of phloroglucinol dimers were tentatively characterized by UHPLC-HRMS and reported for the first time in M. bullata and the genus Mosiera. These results suggest the potential of M. bullata total extract as a natural antifungal product for the control of diseases in agriculture. [ABSTRACT FROM AUTHOR]

This study explores the bioconversion of diosgenin by Yarrowia lipolytica P01a, focusing on enhancing the antioxidant, antifungal, and herbicidal activities of the resulting extracts. The bioconversion process, involving glycosylation and hydroxylation, produced significant amounts of protodioscin and soyasaponin I. The extracts showed superior antioxidant activity, with up to 97.02% inhibition of ABTS· radicals and 33.30% inhibition of DPPH· radicals at 1000 mg L−1 of diosgenin. Antifungal assays revealed strong inhibitory effects against Botrytis cinerea, Alternaria sp., and Aspergillus niger, with maximum inhibition rates of 67.34%, 35.63%, and 65.53%, respectively. Additionally, the herbicidal activity of the bioconverted extracts was comparable to commercial herbicides, achieving 100% inhibition of seed germination in both monocotyledonous and dicotyledonous plants. These findings suggest that the Y. lipolytica P01a-mediated bioconversion of diosgenin could provide a sustainable and eco-friendly alternative for developing natural biofungicides and bioherbicides. [ABSTRACT FROM AUTHOR]

Around 80% of the food consumed worldwide is provided by agriculture, and almost 30% of these products are affected by phytopathogenic agents, which cause numerous plant diseases. Microorganisms have been used as biocontrol agents to eliminate or decrease damage caused by phytopathogens. For the application of biocontrol agents, such as strains of Bacillus velezensis , several parameters need to be considered, including their habitat and molecular and biochemical conditions, such as plant growth promotion and antifungal activity. B. velezensis strains also have potential as control agents against nematodes in greenhouse cultivation, as probiotic supplements for feed, to pretreat lignocellulosic materials, or in wastewater treatments through the enzymes they produce. Many microorganisms have been reported as bioagents for producing ecofriendly, cost-effective, and safe products. Some Bacillus species of bacteria can be used in agricultural applications. Bacillus velezensis in particular has shown promising results for controlling destructive phytopathogens and in biofungicide manufacturing. Some B. velezensis strains can promote plant growth and display antibiotic activities against plant pathogen agents. In this review, we focus on the often-overlooked potential properties of B. velezensis as a bioagent for applications that will extend beyond the traditional agricultural uses. We delve into its versatility and future prospects, the challenges such uses may encounter, and some drawbacks associated with B. velezensis -based products. [ABSTRACT FROM AUTHOR]

Substrate supplementation and co-cultivation approaches were used to enhance activity of biofungicide Trichoderma viride. Biopesticides were produced using corn cobs (T), corn cobs + 1% keratin (K), corn cobs + 5% lignin (L), and corn cobs + 1% keratin + 5% lignin (K+L). Also, biopesticides were produced through co-culturing with Bacillus subtilis MTCC8142, by sequential inoculation (B+T) and simultaneous inoculation (T3+B2) (B2+T3). The highest spore count was produced by (T3+B2) of 6.25x108 spores/g of substrate, followed by (T) of 6.20x108 spores/g of substrate. GC-MS characterization of ethyl acetate extract of biopesticides revealed different metabolites produced under different conditions. The zone of inhibition of extract was greatest for (T) of 21 mm, followed by (K) of 20.7 mm and for (B2+T3) of 18 mm at 10 mg/mL concentration. (K) and (B2+T3) did not affect antifungal properties; however, other substrate-supplemented and co-cultivated biopesticides decreased them. Competition between two microbes prevented (T3+B2) from producing antimicrobial metabolites; hence, no zone of inhibition was observed. The biopesticides (K), (L) and (B2+T3) significantly enhanced growth of chili plants (Capsicum frutescens L.), outperforming other biopesticides. The production of phthalates, also known as phytotoxins, by B+T resulted in a decrease in plant growth. Adding 1% keratin to corn cobs (K) and (B2+T3) sequential inoculation are best ways to boost plant growth promoting activity of T. viride without affecting its biocontrol activity. [ABSTRACT FROM AUTHOR]

Nutmeg (Myristica fragrans) is spice plant which has an important position as a source of essential oils. An important problem in nutmeg cultivation is white root disease which can reduce nutmeg production. Until now, white root disease is still a problem in nutmeg plantations in South Aceh district. One of the solution that can be explored as an environmentally friendly control measure is to use the botanical fungicide coconut shell liquid smoke. This research aims to determine the potential of coconut shell liquid smoke in controlling white root fungus in vitro. The research was carried out in the Plant Protection Laboratory, Faculty of Agriculture, Teuku Umar University. The research design used was a non-factorial Completely Randomized Design (CRD) consisting of nine levels of liquid smoke concentration treatment; control 0%, 0.5%, 1%, 2%, 3%, 4%, 6%, 8%, 10%. Each treatment involved three replications. Data analysis was carried out using analysis of variance and Tukey's least significant difference (HSD) test.The research stages carried out consisted of producing coconut shell liquid smoke, isolating white root fungus from the roots of infected nutmeg plants and potential assay of liquid smoke in inhibiting the growth of white root fungus. In vitro bioassay result showed that liquid smoke treatment 3% was the best treatment because it was the lowest concentration causing total inhibition of the growth of white root fungus. [ABSTRACT FROM AUTHOR]

Maize is one of the most consumed cereal crops worldwide, and it is a strategic crop to the attainment of SDG 2 of Zero hunger. Despite its importance, the cultivation of maize has been significantly impaired by fungal pathogens causing foliar diseases. The occurrence of this disease in maize plantations at the Research Farm of the North-West University, Molelwane, Mafikeng, South Africa prompted this investigation. Samples of diseased maize rhizosphere soil were aseptically collected. Bacteria species associated with the rhizosphere were isolated and characterized as Bacillus siamensis, Enterobacter asburiae, Enterobacter chengduensis, Priestia aryabhattai, Burkholderia sp., Priestia megaterium strain AOA6 and Priestia megaterium strain AOA7. The anti-fungicidal potentials of the bacterial species were evaluated against pathogenic fungal species, Nigrospora sphaerica, Alternaria alternata and Fusarium equiseti in-vitro. The percentage mycelia growths were calculated and the data were subjected to ANOVA using SAS version 9.8. All the seven bacteria isolates tested positive to ammonia production, phosphate solubilization, siderophore production and ACC deaminase tests. The percentage mycelia inhibition showed Nigrospora sphaerica (36.29%), A. alternata (26.19%) and F. equiseti (20.63%) as the order of fungal inhibition by the bacteria species. Furthermore, E. asburiae > P. megatarium strain AOA7 > B. siamensis > P. aryabhattai > E. chengduensis > Bulkholderia sp. were the order of antifungal efficacy of the bacteria species evaluated. In conclusion, the efficacy of the bacteria especially E. asburiae, P. megatarium strain AOA7 and B. siamensis over various fungal pathogens. The result obtained, therefore, justifies the further investigation, formulation and deployment of the bacteria species as biofungicide in the management of foliar diseases of maize. [ABSTRACT FROM AUTHOR]

Objectives: Bacillus subtilis is a plant growth promoting bacterium (PGPB) that acts as a microbial fertilizer and biocontrol agent, providing benefits such as boosting crop productivity and improving nutrient content. It is able to produce secondary metabolites and endospores simultaneously, enhancing its ability to survive in unfavorable conditions and eliminate competing microorganisms. Optimizing cultivation methods to produce B. subtilis MSCL 897 spores on an industrial scale, requires a suitable medium, typically made from food industry by-products, and optimal temperature and pH levels to achieve high vegetative cell and spore densities with maximum productivity. Results: This research demonstrates successful pilot-scale (100 L bioreactor) production of a biocontrol agent B. subtilis with good spore yields (1.5 × 109 spores mL−1) and a high degree of sporulation (>80%) using a low-cost cultivation medium. Culture samples showed excellent antifungal activity (1.6–2.3 cm) against several phytopathogenic fungi. An improved methodology for inoculum preparation was investigated to ensure an optimal seed culture state prior to inoculation, promoting process batch-to-batch repeatability. Increasing the molasses concentration in the medium and operating the process in fed-batch mode with additional molasses feed, did not improve the overall spore yield, hence, process operation in batch mode with 10 g molasses L−1 is preferred. Results also showed that the product quality was not significantly impacted for up to 12 months of storage at room temperature. Conclusion: An economically-feasible process for B. subtilis-based biocontrol agent production was successfully developed at the pilot scale. [ABSTRACT FROM AUTHOR]

Fusarium wilt is a destructive fungal disease of okra that limits okra production in the okra-growing region. In 2015, a new pathogen was identified in an okra field that caused wilt disease in okra. However, no detailed morphological, molecular, or physiological studies have been conducted to characterize this pathogen. The causal agent was identified as Fusarium buharicum by morphological characterization and elongation factor-1α gene sequencing. Moreover, to determine pathogen characteristics that may be useful for future disease management, the effects of different media, temperature, and pH on mycelium growth, conidia production, and germination were studied. Potato sucrose agar and potato dextrose agar were the best media for mycelial growth, whereas rice husk media were suitable for conidial production. The optimal temperature for mycelial growth and conidial germination was 28 °C. Meanwhile, pH ranging from 5 to 9 was suitable for both mycelial growth and conidial germination. The host range assay revealed that F. buharicum infected only okra, but not the other crops tested. Furthermore, in planta biofungicides screening showed that Ecohop (Trichoderma atroviride) reduced wilt disease incidence by 93.8% over control. Characterization of the pathogen along with biofungicide screening would be helpful for the detection and development of management practices to eliminate production loss in the okra field caused by an emerging fungal pathogen. [ABSTRACT FROM AUTHOR]

Potato growers worldwide have been at war for more than 150 years with an enemy whose lifecycle, genome size and architecture, infection rate, and economic impacts are the epitome of a plant pathogen. Phytophthora infestans is an oomycete that causes the notorious late blight infection in potato and tomato fields. This study explored the benefits of the multitalented plant symbiotic fungi Trichoderma spp. and their metabolites as potential biopesticides against P. infestans. Eleven strains of Trichoderma spp. were obtained from soil and tree barks and were identified using DNA sequence analysis of three molecular markers. The antagonistic potential of the strains against P. infestans was first evaluated in vitro. In dual-culture assays, P. infestans growth was significantly inhibited (53 to 95%) by different Trichoderma spp. through direct mycoparasitism, competition for space and nutrients, or antibiosis. The cell-free filtrates (CFFs) of different Trichoderma strains were obtained and characterized for anti-Phytophthora activities as well as biochemical stability. The obtained results indicated that Trichoderma CFFs were chemically stable and strongly decreased P. infestans’ mycelial growth and zoospore motility and viability. Similarly, in leaf-disk assays, Trichoderma CFFs showed significant protection against P. infestans infection. Ultraperformance liquid chromatography analysis revealed the presence of harzianic acid, iso-harzianic acid, and 6-pentyl-2H-pyran-2-one as major compounds in different Trichoderma CFFs. Furthermore, selected Trichoderma strains significantly protected potato plants against soil-mediated late blight infection. Finally, Trichoderma spp. showed high compatibility with a copper-based fungicide, especially at lower concentrations, suggesting that both protective agents could be combined in integrated pest management programs. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Penicillium digitatum is the causal agent of green mold, a primary postharvest disease of citrus fruits. This study evaluated the efficacy of a novel photoactive chitosan–riboflavin bioconjugate (CH-RF) to control green mold in vitro and in lemon fruit. The results showed total inhibition of P. digitatum growth on APDA supplemented with CH-RF at 0.5% (w/v) and a significant reduction of 84.8% at 0.25% (w/v). Lemons treated with CH-RF and kept under controlled conditions (20 °C and 90–95% relative humidity) exhibited a noteworthy reduction in green mold incidence four days post-inoculation. Notably, these effects persisted, with all treatments remaining significantly distinct from the control group until day 14. Furthermore, CH-RF showed high control of green mold in lemons after 20 days of cold storage (5 ± 1 °C). The disease incidence five days after cold storage indicated significant differences from the values observed in the control. Most CH-RF treatments showed enhanced control of green mold when riboflavin was activated by white-light exposure. These findings suggest that this novel fungicide could be a viable alternative to conventional synthetic fungicides, allowing more sustainable management of lemon fruit diseases. [ABSTRACT FROM AUTHOR]

Rhizoctonia root rot of eggplant, caused by Rhizoctonia solani, is an economically important disease. Niallia circulans YRNF1 and arbuscular mycorrhizal fungi (AMF) were assessed for their biocontrol and biofertilizing effects against R. solani, as potential replacements for synthetic fungicides and fertilizers. The diazotrophic N. circulans YRNF1, isolated from soil, reduced in vitro growth of R. solani by 42%. GCMS analysis of culture filtrate of N. circulans YRNF1 detected bioactive compounds, including butyric acid (85%) and ethylene glycol (8%). In greenhouse experiments, combined application of N. circulans YRNF1 and AMF reduced the severity of eggplant root rot by 26%. This combined treatment triggered the transcriptional expression of five resistance genes (JERF3, PAL1, C3H, CHI2, and HQT) in the treated eggplants. Biochemical analyses of the infected eggplant roots treated with the combined bio-inoculants showed enhancement of the phenol content (+188%), and increased antioxidant enzyme activity, mainly of POD (+104%) and PPO (+72%). Combined application of N. circulans YRNF1 and AMF also promoted eggplant growth and improved the total NPK concentrations in treated plant leaves. Inoculation of eggplant with N. circulans YRNF1 in the presence of AMR increased the mycorrhization level. This is the first report of N. circulans and AMF as potential agents for biological control of Rhizoctonia root rot and growth promotion of eggplant. [ABSTRACT FROM AUTHOR]

Biocontrol agents against rice blast fungus Magnaporthe oryzae have attracted more attention recently. In this study, the antifungal activity of AMEP412 protein against M. oryzae was assessed. AMEP412 induced a visible inhibition zone on M. oryzae coated agar plates, which preliminarily verified its antifungal activity. On complete medium agar plates, the aerial hyphae growth was significantly slowed down by AMEP412 (0.0125–0.05 mg/mL), with inhibition rates ranging from 21.25 to 54.40%. The half maximal effective concentration (EC50 value) was 0.041 mg/mL. On oats medium agar plates, the spore development was also inhibited both in quantity and in pathogenicity. The treatment with AMEP412 (0.0125, 0.025 and 0.05 mg/mL) was associated with a decrease in the spore number by 78.13%, 88.98% and 95.72%, and the lesion area on rice leaves by 38.2%, 58.0% and 63.0%, respectively. Under microscopic observation, the aerial hyphae showed irregular external shape and the spores showed abnormal transverse septum. Fluorescence labeling revealed that AMEP412 localized on the surface of aerial hyphae and the septum of spores, indicating that the membrane integrity and permeability were probably disrupted. The predicted structure model of AMEP412 displayed obvious positive net charge and hydrophobic face, which supported the interaction between AMEP412 and M. oryzae. Finally, the pathogenicity test on rice seedlings showed that AMEP412 (0.05 mg/mL) reduced the lesion area by 90.8%. Our results revealed that AMEP412 had antifungal activity against M. oryzae in vivo and in vitro, and could be developed as an antifungal agent in the control of rice blast.

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. [Figure: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

This study explores the bioconversion of diosgenin by Yarrowia lipolytica P01a, focusing on enhancing the antioxidant, antifungal, and herbicidal activities of the resulting extracts. The bioconversion process, involving glycosylation and hydroxylation, produced significant amounts of protodioscin and soyasaponin I. The extracts showed superior antioxidant activity, with up to 97.02% inhibition of ABTS· radicals and 33.30% inhibition of DPPH· radicals at 1000 mg L−1 of diosgenin. Antifungal assays revealed strong inhibitory effects against Botrytis cinerea, Alternaria sp., and Aspergillus niger, with maximum inhibition rates of 67.34%, 35.63%, and 65.53%, respectively. Additionally, the herbicidal activity of the bioconverted extracts was comparable to commercial herbicides, achieving 100% inhibition of seed germination in both monocotyledonous and dicotyledonous plants. These findings suggest that the Y. lipolytica P01a-mediated bioconversion of diosgenin could provide a sustainable and eco-friendly alternative for developing natural biofungicides and bioherbicides.

One of the major difficulties of many countries today is to supply food in sufficient quantities and quality to provide for an increasing population without damaging the soil or the ecosystem. In order to overcome the food losses and improve food production, biotechnological and nanotechnological advances come to the fore. In this study we present a comprehensive production process for a food/crop protective which acts as a microbial biofungicide, produced from a microorganism rich in antimicrobial bioactive substances. In this context, Bacillus pumilus was produced in a bioreactor and their spores were encapsulated in alginate/poly (vinyl alcohol) nanoparticles. In the first part of the study, a high quantify of spores was produced during a short incubation period, reaching 2.0 × 1011 CFU/mL using 1% inoculum. In the second part, B. pumilus loaded nanoparticles with a size of 695 nm were produced by electrospinning. Finally, the effects of B. pumilus spores and their nanoparticles on mycelial growth of Colletotrichum gloeosporioides were investigated. After electrospinning, the viability of spores was found to be 2.0 × 106 CFU/mL, and nanoparticles showed 28% inhibition of mycelial growth against C. gloeosporioides. Moreover, in vivo studies of spores and nanoparticles also showed efficient fruit protection. As a result, the use and controlled release of nanoparticles loaded with Bacillus spores can be considered a natural and new technique to prevent postharvest fungal decay disease on the crops. [ABSTRACT FROM AUTHOR]

Background. Fungal diseases can cause significant losses in the tomato crop. Phytophthora infestans causes the late blight disease, which considerably affects tomato production worldwide. Weed-based plant extracts are a promising ecological alternative for disease control. Methods. In this study, we analyzed the plant extract of Argemone mexicana L. using chromatography-mass spectrometry analysis (GC-MS). We evaluated its impact on the severity of P. infestans, as well as its effect on the components of the antioxidant defense system in tomato plants. Results. The extract from A. mexicana contains twelve compounds most have antifungal and biostimulant properties. The findings of the study indicate that applying the A. mexicana extract can reduce the severity of P. infestans, increase tomato fruit yield, enhance the levels of photosynthetic pigments, ascorbic acid, phenols, and flavonoids, as well as decrease the biosynthesis of H2O2, malondialdehyde (MDA), and superoxide anion in the leaves of plants infected with this pathogen. These results suggest that using the extract from A. mexicana could be a viable solution to control the disease caused by P. infestans in tomato crop. [ABSTRACT FROM AUTHOR]

Maize grain production in the tropics is affected by Fusarium verticillioides, leading to significant losses in yield and quality. Fungicides are commonly used to control foliar diseases and increase grain yield, but have limited efficacy against F. verticillioides and may even stimulate the fungus to produce mycotoxins. Biocontrol can reduce F. verticillioides populations and fumonisin, but little is known about the resulting microbial interactions on the phylloplane and their relationship with F. verticillioides. This study aimed at evaluating the impact of different foliar treatments on the cultivable phylloplane community of fungi and bacteria and their potential in controlling F. verticillioides in maize. Results showed that two sprays of Bacillus subtilis BIOUFLA2 increased the percentage of native phylloplane antagonist bacteria and fungi against F. verticillioides by 25.0% and 27.3%, respectively, compared with the water control. However, two sprays with a triazole + strobilurin fungicide at different phenological stages in maize reduced such antagonistic communities. From field trials, 34 bacteria and 13 fungi from the phylloplane were selected for their inhibitory activity against F. verticillioides, with most coming from the exclusive treatment with BIOUFLA2. The study also revealed that the biocontrol agent‐recruited phylloplane indigenous lineages act through antibiosis, competition, and parasitism. Therefore, the adoption of biocontrol to limit F. verticillioides population build‐up not only has a direct activity on the pathogen but also recruits fungal and bacterial antagonists that may act additively or synergistically with the applied biocontrol agent. [ABSTRACT FROM AUTHOR]

The self-digestive solution (SDS) of the biocontrol bacterium Lysobacter enzymogenes LE16 shows strong antagonistic activities against multiple soil-borne phytopathogens but the positive evidence of this bacterium against plant foliar disease is still scanty. Thus, laboratory, greenhouse, and field experiments were carried out to estimate the efficacies of SDS, S-SDS (stored at room temperature for 12 months), and H-SDS (heated at 100°C for 30 min) against plant powdery mildew. This bacterium produced hydrolases (phosphatase, protease, lysozyme, chitinase, and β-1,3-glucanase) that degrade pathogen cell components and siderophores that compete for iron with phytopathogens. The top five antimicrobial metabolites identified in SDS were pyroglutamic acid, deoxycytidine, pyrrole-2-carboxylic acid, 13-oxo-9,11-tridecadienoic acid, and 3'-amino-3'-deoxythimidine. Among them, pyroglutamic acid may play a vital role in powdery mildew control. As a result, SDS, S-SDS, and H-SDS strongly inhibited the conidial germination of Erysiphe cichoracearum and Sphaerotheca fuliginea. The application of SDS significantly increased the activity of antioxidant enzymes in crop leaves and effectively controlled tobacco and cucumber powdery mildew in the greenhouse and the field. Therefore, L. enzymogenes LE16 can effectively control powdery mildew. The underlying mechanisms may be attributed to the induction of plant systemic resistance and the production of antifungal substances. [ABSTRACT FROM AUTHOR]

Background Fungal diseases can cause significant losses in the tomato crop. Phytophthora infestans causes the late blight disease, which considerably affects tomato production worldwide. Weed-based plant extracts are a promising ecological alternative for disease control. Methods In this study, we analyzed the plant extract of Argemone mexicana L. using chromatography-mass spectrometry analysis (GC-MS). We evaluated its impact on the severity of P. infestans, as well as its effect on the components of the antioxidant defense system in tomato plants. Results The extract from A. mexicana contains twelve compounds most have antifungal and biostimulant properties. The findings of the study indicate that applying the A. mexicana extract can reduce the severity of P. infestans, increase tomato fruit yield, enhance the levels of photosynthetic pigments, ascorbic acid, phenols, and flavonoids, as well as decrease the biosynthesis of H2O2, malondialdehyde (MDA), and superoxide anion in the leaves of plants infected with this pathogen. These results suggest that using the extract from A. mexicana could be a viable solution to control the disease caused by P. infestans in tomato crop.

New solutions to reduce the use of chemical pesticides to combat plant diseases and to meet societal and political demands are needed to achieve sustainable agriculture. Tomato production, both in greenhouses and in open fields, is affected by numerous pathogens. The aim of this study is to assess the possibility of controlling both late blight and powdery mildew in tomatoes with a single biocontrol product currently under registration. The biocontrol product AXP12, based on the lysate of Willaertia magna C2c Maky, has already proved its efficacy against downy mildew of grapevine and potato late blight. Its ability to elicit tomato defenses and its efficacy in the greenhouse and in the field were tested. This study establishes that AXP12 stimulates the tomato genes involved in plant defense pathways and has the capacity to combat in greenhouse and field both late blight (Phytophtora infestans) and powdery mildew (Oidium neolycopersici and Leveillula taurica) of tomato. [ABSTRACT FROM AUTHOR]

The entomopathogenic fungus Beauveria bassiana is used commercially as a microbial insecticides against a wide range of agricultural insect pests. Some strains of B. bassiana protect the plants from pathogens, but the underlying mechanisms are largely unknown. Here, we found that prophylactic sprays of commercial bioinsecticide Botanigard on cucumber, tomato, and strawberry plants suppressed the severity of economically damaging powdery mildews. On leaf surfaces, hyphal elongation and spore germination of cucumber powdery mildew, Podosphaera xanthii, were inhibited, but B. bassiana strain GHA, the active ingredient isolated from Botanigard, only inhibited hyphal elongation but had no effect on spore germination of P. xanthii. In addition, strain GHA suppressed powdery mildew symptoms locally, not systemically. Treatment with Botanigard and strain GHA induced a hypersensitive response (HR)-like cell death in epidermal cells of the cucumber leaves in a concentration-dependent manner and inhibited penetration by P. xanthii. Transcriptome analysis and mass spectrometry revealed that GHA induced expression of salicylic acid (SA)-related genes, and treatment with Botanigard and GHA increased the SA level in the cucumber leaves. In NahG-transgenic tomato plants, which do not accumulate SA, the biocontrol effect of tomato powdery mildew by GHA was significantly reduced. These results suggested that B.bassiana GHA induces SA accumulation, leading to the induction of HR-like cell death against powdery mildew and subsequent suppression of fungal penetration. Thus, Botanigard has the potential to control both insect pests and plant diseases. [ABSTRACT FROM AUTHOR]

Aims Black scurf disease, caused by Rhizoctonia solani , is a severe soil-borne and tuber-borne disease, which occurs and spreads in potato growing areas worldwide and poses a serious threat to potato production. New biofungicide is highly desirable for addressing the issue, and natural products (NPs) from Xenorhabdus spp. provide prolific resources for biofungicide development. In this study, we aim to identify antifungal NPs from Xenorhabdus spp. for the management of this disease. Methods and results Out of the 22 Xenorhabdus strains investigated, Xenorhabdus budapestensis 8 (XBD8) was determined to be the most promising candidate with the measured IC50 value of its cell-free supernatant against R. solani as low as 0.19 ml l−1. The major antifungal compound in XBD8 started to be synthesized in the middle logarithmic phase and reached a stable level at stationary phase. Core gene deletion coupled with high-resolution mass spectrometry analysis determined the major antifungal NPs as fabclavine derivatives, Fcl-7 and 8, which showed broad-spectrum bioactivity against important pathogenic fungi. Impressively, the identified fabclavine derivatives effectively controlled black scurf disease in both greenhouse and field experiments, significantly improving tuber quality and increasing with marketable tuber yield from 29 300 to 35 494 kg ha−1, comparable with chemical fungicide fludioxonil. Conclusions The fabclavine derivatives Fcl-7 and 8 were determined as the major antifungal NPs in XBD8, which demonstrated a bright prospect for the management of black scurf disease. [ABSTRACT FROM AUTHOR]

Trichoderma spp., is a highly efficient antagonist of root pathogens, such as Rhizoctonia solani, which causes loss in many crops. The aim of this research was to evaluate in vitro the antagonistic capacity of T. viride, T. koningii, T. harzianum and Trichoderma spp. isolates against R. solani from a potato crop. In confrontation tests, all Trichoderma isolates were classified as antagonists class 2 according to Bell scale, where T. harzianum and T. koningii showed more than 60% inhibition of the radial growth of R. solani at 120 h. In the interaction between T. harzianum and Trichoderma spp. with R. solani, as mycoparasitism strategy, vacuolization, lysis, coiling, and penetration were demonstrated, the last two were present in all Trichoderma isolates evaluated. [ABSTRACT FROM AUTHOR]

Melatonina natural harmless molecule—displays versatile roles in human health and crop disease control such as for rice blast. Rice blast, caused by the filamentous fungus Magnaporthe oryzae, is one devastating disease of rice. Application of fungicides is one of the major measures in the control of various crop diseases. However, fungicide resistance in the pathogen and relevant environmental pollution are becoming serious problems. By screening for possible synergistic combinations, here, we discovered an eco‐friendly combination for rice blast control, melatonin, and the fungicide isoprothiolane. These compounds together exhibited significant synergistic inhibitory effects on vegetative growth, conidial germination, appressorium formation, penetration, and plant infection by M. oryzae. The combination of melatonin and isoprothiolane reduced the effective concentration of isoprothiolane by over 10‐fold as well as residual levels of isoprothiolane. Transcriptomics and lipidomics revealed that melatonin and isoprothiolane synergistically interfered with lipid metabolism by regulating many common targets, including the predicted isocitrate lyase‐encoding gene MoICL1. Furthermore, using different techniques, we show that melatonin and isoprothiolane interact with MoIcl1. This study demonstrates that melatonin and isoprothiolane function synergistically and can be used to reduce the dosage and residual level of isoprothiolane, potentially contributing to the environment‐friendly and sustainable control of crop diseases. [ABSTRACT FROM AUTHOR]

The vast majority of modern chemical poisons solve the problem of diseases and pests on agricultural plants. However, their use causes deterioration of the ecological condition of agrocenoses. The biological activity of the soil of the root zone of corn was studied during the pre-sowing treatment of seeds with a complex of microorganisms No.1 + No.2. It was found that the use of a complex of microorganisms No. 1 + No. 2 reduced the number of micromycetes by 1.8-2.5 times. The level of antifungal activity increased 4-7 times compared to the control, and 1.5 times compared to the options where chemical preparations were used. Therefore, bioagents of complex No. 1 and No. 2, being introduced into the root zone of corn plants, initiate changes in the functioning of the microbiocenosis and protect plants during the growing season. We believe that the complex of microorganisms No. 1 and No. 2 is promising for further biotechnological developments. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) is one of the most important food crops worldwide, and Rhizoctonia solani infection is one of the most common diseases. The objective of this study was to evaluate the antifungal activity of Vitis vinifera byproducts (VIDES) and flesh-coloured potato (FCP) extracts against Rhizoctonia sp. in potato crops. Photosynthetic traits, phenolic profiles, and antioxidant and enzymatic activities were determined. The VIDES extract showed a 151.4% improvement in stomatal conductance and a 258.5% improvement in the photosynthetic rate compared to the plants without infection. Regarding the enzymatic antioxidant activity, the best response was found in the FCP treatments with 30 min of application, with increases of 25%, 161%, and 450% in ascorbate peroxidase, catalase (CAT), and glutathione reductase (GR) activities, respectively, compared to plants without infection. For the VIDES extract, a 15 min application produced an 83% increase in CAT activity, whereas a 181% increase in GR activity compared to plants without infection was produced after a 30 min application. A similar behaviour was observed for antioxidant compounds, where FCP had a higher concentration of compounds and antioxidant activity. This finding suggests that FCP and VIDES promote the synthesis of plant-defence compounds against Rhizoctonia sp. in potato crops, in which the application time is a determining factor. [ABSTRACT FROM AUTHOR]

The use of plant extracts with antifungal effects is a plausible alternative solution which is increasingly attracting the attention of researchers worldwide, to address the multiple limitations associated with the use of synthetic agrochemicals. The antifungal potential of essential oils (EO) fractions of Callistemon citrinus, were investigated in vitro by the supplemented media method against Bipolaris oryzae and Alternaria padwickii, two seed-borne fungi of rice in Cameroon. The EO fractions obtained by hydrodistillation of the plant's fresh and dry leaves inhibited to varying degrees the mycelia growth of the two pathogens. The EO's fractions obtained from dry leaves were more active than those extracted from fresh leaves. Fractions of EO showed fungicidal effects, with minimum inhibitory concentrations (MIC) varying between 3616 and 7232 μg/ml. The dry leaves EO fraction DF2 exhibited the strongest antifungal activity (MIC = 3616 μg/ml), followed by the fresh leaves fraction FF2 (MIC = 4520 μg/ml) and the total dry leaves EO DM (MIC = 4520 μg/ml), against B. oryzae. Those fractions (DF2, FF2 and DM) also exhibited the highest MIC (MIC = 4520 μg/ml) against Alternaria padwickii. The GC-SM analysis of EO fractions showed that, the antifungal activity was inversely associated to the content of the major bioactive compound 1,8-cineole; 60.67, 66.36 and 86.39% 86.39%; and proportional to α-terpineol; 13.39, 10.52 and 3.5%; for EO fractions DF2, FF2 and MD DM, respectively. Seed treatment of three of rice varieties with fractions DF2, FF2 and DM respectively at the doses of 1.5, 2 and 3.5%, reduced the seed to seedling transmission rate of B. oryzae by 100% and increased the germination rate of these seeds between 2 and 12%. Our results suggest the use of EO from C. citrinus as biofungicides for the treatment of rice seeds infected with B. oryzae and A. padwickii. [ABSTRACT FROM AUTHOR]

Penicillium digitatum is the causal agent of green mold, a primary postharvest disease of citrus fruits. This study evaluated the efficacy of a novel photoactive chitosan–riboflavin bioconjugate (CH-RF) to control green mold in vitro and in lemon fruit. The results showed total inhibition of P. digitatum growth on APDA supplemented with CH-RF at 0.5% (w/v) and a significant reduction of 84.8% at 0.25% (w/v). Lemons treated with CH-RF and kept under controlled conditions (20 °C and 90–95% relative humidity) exhibited a noteworthy reduction in green mold incidence four days post-inoculation. Notably, these effects persisted, with all treatments remaining significantly distinct from the control group until day 14. Furthermore, CH-RF showed high control of green mold in lemons after 20 days of cold storage (5 ± 1 °C). The disease incidence five days after cold storage indicated significant differences from the values observed in the control. Most CH-RF treatments showed enhanced control of green mold when riboflavin was activated by white-light exposure. These findings suggest that this novel fungicide could be a viable alternative to conventional synthetic fungicides, allowing more sustainable management of lemon fruit diseases.

Dollar spot caused by Clarireedia spp. (formerly Sclerotinia homoeocarpa) is an economically destructive fungal disease of turfgrass that can significantly compromise turf quality, playability, and aesthetic value. Fungicides are frequently used to manage the disease but are costly and potentially unfavorable to the environment. Repeated use of some active ingredients has resulted in reduced efficacy on C. jacksonii causing dollar spot in cool-season turfgrasses in the US. Experiments were conducted to study fungicide sensitivity of Clarireedia spp. as well as to develop alternatives to fungicides against dollar spot on warm-season turfgrass in Georgia. First, 79 isolates of Clarireedia spp. collected across the state were tested on fungicide-amended agar plates for their sensitivity to thiophanate-methyl (benzimidazole) and propiconazole (dimethyl inhibitor). Seventy-seven isolates (97.5%) were sensitive (0.001 to 0.654 mg/mL) and two isolates (2.5%) were found resistant (>1000 mg/mL) to thiophanate-methyl. However, in the case of propiconazole, 27 isolates (34.2%) were sensitive (0.005 to 0.098 mg/mL) while 52 isolates (65.8%) were resistant (0.101 to 3.820 mg/mL). Next, the efficacy of three bio- and six synthetic fungicides and ten different combinations were tested in vitro against C. monteithiana. Seven bio- and synthetic fungicide spray programs comprising Bacillus subtilis QST713 and propiconazole were further tested, either alone or in a tank mix in a reduced rate, on dollar spot infected bermudagrass 'TifTuf' in growth chamber and field environments. These fungicides were selected as they were found to significantly reduce pathogen growth up to 100% on in vitro assays. The most effective spray program in growth chamber assays was 100% B. subtilis QST713 in rotation with 75% B. subtilis QST713 + 25% propiconazole tank mix applied every 14 days. However, the stand-alone application of the biofungicide B. subtilis QST713 every seven days was an effective alternative and equally efficacious as propiconazole, suppressing dollar spot severity and AUDPC up to 75%, while resulting in acceptable turf quality (>7.0) in field experiments. Our study suggests that increased resistance of Clarireedia spp. to benzimidazoles and dimethyl inhibitors warrants continuous surveillance and that biofungicides hold promise to complement synthetic fungicides in an efficacious and environmentally friendly disease management program. [ABSTRACT FROM AUTHOR]

The major safety risk of maize grain is contamination with mycotoxins. In this study, a maize-coating formulation containing freeze-dried culture filtrate of Streptomyces philanthi RL-1-178 (DCF RL-1-178) was developed and evaluated to prevent the growth of mycotoxins during maize grain storage. In vitro studies using confrontation tests on PDA plates indicated that S. philanthi RL-1-178 inhibited the growth of Aspergillus parasiticus TISTR 3276 (89.0%) and A. flavus PSRDC-4 (95.0%). The maize grain coating formulations containing the DCF RL-1-178 (0, 5, 10, and 15% (v/v)) and the polymer polyvinylpyrrolidone (PVP-K90, 4.0% (w/v)) were tested for their efficacy in In vitro and during 5 months storage. In In vitro assay, maize coating formular containing the optimum concentration (15.0%, v/v) of the DCF RL-1-178 exhibited 54.80% and 54.17% inhibition on the growth of A. parasiticus TISTR 3276 and A. flavus PSRDC-4 respectively. The inhibition was also illustrated by the microstructures of interactions between the coated maize grains with or without the DCF RL-1-178 and the fungal pathogens observed under microscope and SEM. Incorporating the DCF RL-1-178 or fungicidal Metalaxyl® into the polymer PVP-K90 maize grains coating resulted in the complete inhibition of the production of aflatoxin B1 (analysed by HPLC) by the two aflatoxigenic pathogens after 5 months storage at room temperature. However, the shelf-life was shortened to only 3 months during storage at room temperature with 90% relative humidity. Overall, the application of the 10–15% DCF RL-1-178 into the maize grain coating formular provides a new alternative measure to control the mycotoxins during storage for at least 5 months. The In vitro cell cytotoxicity study showed that a concentration of 15% (v/v) or 1000 μg/mL of the DCF RL-1-178 had a strong cytotoxic effect on Vero cells. These findings indicate that DCF RL-1-178 is a potential biofungicide for controlling mycotoxins contamination in maize seed storage for planting, but not maize grain storage for animal feed. [ABSTRACT FROM AUTHOR]

Tar spot disease in corn, caused by Phyllachora maydis, can reduce grain yield by limiting the total photosynthetic area in leaves. Stromata of P. maydis are long-term survival structures that can germinate and release spores in a gelatinous matrix in the spring, which are thought to serve as inoculum in newly planted fields. In this study, overwintered stromata in corn leaves were collected in Central Illinois, surface sterilized, and caged on water agar medium. Fungi and bacteria were collected from the surface of stromata that did not germinate and showed microbial growth. Twenty-two Alternaria isolates and three Cladosporium isolates were collected. Eighteen bacteria, most frequently Pseudomonas and Pantoea species, were also isolated. Spores of Alternaria, Cladosporium, and Gliocladium catenulatum (formulated as a commercial biofungicide) reduced the number of stromata that germinated compared to control untreated stromata. These data suggest that fungi collected from overwintered tar spot stromata can serve as biological control organisms against tar spot disease. [ABSTRACT FROM AUTHOR]

Aims The American leaf spot, caused by Mycena citricolor , is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environment friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor , the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta. Methods and results Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e. Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. crassum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays. Conclusions Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor , reducing incidence and severity, and preventing plant mortality. [ABSTRACT FROM AUTHOR]

Background: Protected agriculture (PA) is an alternative allowing the control of environmental variables to produce healthy vegetables. Biofertilizers and biofungicides can reduce the chemical load of pesticides. There is abundant literature documenting individual aspects, such as control of environmental variables, irrigation, biological control, and cost assessments. However, there are no reports documenting integral approaches in which variables are considered altogether in a successful case study of mid-tech technology, suitable in middle-income countries like México. We tested if mid-tech greenhouses using biocontrol and biofertilization can increase profits, using tomato as a model system. This work provides considerations about middle-income countries’ agriculture and the need for a multidisciplinary approach to offer cost-effective, sustainable alternatives to producers. Results: This technology yielded up to 254 tons/ha·year of tomato, achieving reductions of 44–60% in water consumption, 25% in chemical nitrogen-fertilization, and 28% in the cost unit of production, increasing the profits by ∼45% in relation to Mexican conventional greenhouses management. Conclusions: This case study has shown that it is possible to significantly increase profits in mid-tech greenhouse tomato production by increasing productivity and crop quality and decreasing the use of water and agrochemicals through greenhouse automatization, crop management, and beneficial bacteria applied to crops. This manuscript includes a video, supplementary to the main contributions of the project. Please visit this URL: https://youtu.be/uRBGgJqfkLE.How to cite: Serrano-Carreón L, Aranda-Ocampo S, Balderas-Ruíz KA, et al. A case study of a profitable mid-tech greenhouse for the sustainable production of tomato, using a biofertilizer and a biofungicide. Electron J Biotechnol 2022;59. https://doi.org/10.1016/j.ejbt.2022.06.003.

Moniliophthora roreri has been considered one of the most worrisome limitations of cocoa cultivation in Colombia and the world due to its affectation with serious damage to the fruit. The current applied agrochemicals have not been sufficient for its control and have various negative effects on the crop and its environment. For that reason, it is necessary to perform research aimed at proposing effective ecologically viable control alternatives for the disease without affecting the environment and the producer's health. In Colombia, there are plant species of high interest for the development of biopreparations due to their multiple benefits, including antimicrobial effects, which allow the reduction of negative impacts on agricultural production. In this way, the present project evaluated the optimal conditions for the extraction process of compounds that maximize the antifungal potential of Capsicum frutescens, using the response surface methodology (MSR) under controlled laboratory conditions. The evaluation was made with continuous factors (temperature in °C and concentration in v/v), and in the same way with categorical factors such as the solvent type A (96 % ethyl acetate) and E (96 % ethanol), finding that the optimal conditions to obtain a percentage of inhibition greater than 90 % of M. roreri under laboratory conditions, correspond to extracts that were obtained using 62 % ethyl acetate as a solvent, at a temperature of 75 °C. It can be inferred that these are the conditions that allow a better dragging of compounds of antifungal interest of the species C. frutescens. Therefore, they could be considered as potential raw material for the production of biological agricultural inputs. [ABSTRACT FROM AUTHOR]

Fusarium wilt is one of the major causes of global losses in the banana industry. The application of extracellular DNA (eDNA) is explored as a natural fungicide. eDNA is categorized on the basis of the receiving cell's perception, namely self and non-self. The application of self-eDNA in agriculture presents the potential for limiting the growth of pathogens, while non-self-eDNA, as a vaccine for plants. This study evaluated whether the eDNA from Fusarium oxysporum f. sp. cubense (Foc) could limit the growth of Foc itself (self-inhibition test) while increasing the resistance of banana plant (priming test). A self-inhibition test showed that the administration of 400 and 800 μg mL−1 eDNA inhibited Foc TR4 spore germination. A priming test was carried out on banana plantlets in the interaction medium containing eDNA Foc TR4 suspension with final concentrations of 40, 80, and 200 μg mL−1. After 24 h, the plantlets were infected with a suspension of 106 spore mL−1. Increased resistance was observed in plantlets treated with 200 μg mL−1 of Foc TR4 eDNA, as indicated by the decrease in leaf symptoms and rhizome discoloration. The accumulation of O2- and H2O2 was observed 24 h after priming as was a significant increase in the relative expression of CAT, PR1, and chitinase 1 genes on day 9 post-infection. In conclusion, eDNA Foc TR4 as a growth inhibitor of pathogen and a priming agent to the banana plantlets could be considered as a biofungicide candidate to induce the resistance of banana plants. [ABSTRACT FROM AUTHOR]

The present work aimed to study the chemical composition and bioactivity of the leaf essential oil of Cupressus sempervirens L. and Cupressus lusitanica Mill. (Cupressaceae) on mycelial growth and germination of Colletotrichum fructicola conidia at the essential oil concentrations of 0.1, 0.5, 1.0, 1.5, and 2.0 µL·mL−1. The essential oil of C. sempervirens presented β-thujene as the major compound (31.4 wt.%), whereas C. lusitanica essential oil was composed mainly of α-pinene (22.7 wt.%). The bioactivity tests showed that both essential oils were ineffective in controlling adult C. fructicola individuals at the tested doses. However, antifungal activity of the oils against germination of the conidia was observed, in which C. sempervirens and C. lusitanica essential oils inhibited 50 % and 38 % of C. fructicola conidia germination at the concentration of 2 µL·mL−1. Morphological alterations of hyphae were also observed after exposure to C. sempervirens essential oil at the dose of 2 µL·mL−1. [ABSTRACT FROM AUTHOR]

The harmful effect of synthetic fungicides on the environment and the development of resistance by fungi raises concerns about their security and future efficacy. In this work, we investigated plant by-products with the antifungal activity that could be safe alternatives to conventional fungicides. The in vitro antifungal potential of plant by-product extracts showed that garlic peel extract (GPE) was the most effective against several phytopathogenic fungi. Accordingly, in ex situ assays with apples, GPE significantly reduced the lesion size caused by subepidermal inoculation with Colletotrichum acutatum spores. In addition, Saccharomyces cerevisiae mutant strains affected in ergosterol synthesis showed higher resistance to GPE than the parental strain, indicating that the extract might target an intermediate of this pathway. Moreover, GPE affects the cell wall, given that bck1 and mkk1/mkk2 mutants were less able to cope with the stress because of the impairment of the remodeling mechanisms. Regarding the apoptosis-deficient mutant yca1, sensitivity was similar to that of the parental strain, suggesting that the extract does not induce apoptosis. A diverse group of sulfur compounds was identified by gas chromatography–mass spectrometry (GC/MS). Our findings contribute to the elucidation of the antifungal mechanism of GPE and highlight its potential as an alternative biofungicide in agriculture. [ABSTRACT FROM AUTHOR]

Main Conclusion: Molecular studies have elucidated Trichoderma’s biocontrol mechanisms. Since fungicides have limited use, Trichoderma could control disease by new metabolic routes and epigenetic alterations. Due to environmental and health hazards, agrochemicals have been a concern since they were introduced in agriculture. Trichoderma, a well-known fungal genus with different mechanisms of action, is an alternative to pesticides and a great tool to help minimize disease incidence. Trichoderma-treated plants mainly benefit from disease control and growth promotion through priming, and these fungi can modulate plants’ gene expression by boosting their immune system, accelerating their response to threats, and building stress tolerance. The latest studies suggest that epigenetics is required for plant priming and could be essential for growth promotion, expanding the possibilities for producing new resistant plant varieties. Trichoderma’s propagules can be mass produced and formulated depending on the delivery method. Microsclerotia-based bioproducts could be a promising way of increasing the reliability and durability of marketed products in the field, as well as help guarantee longer shelf life. Developing novel formulations and selecting efficient Trichoderma strains can be tiresome, but patent search indicates an increase in the industrialization and commercialization of technologies and an expansion of companies’ involvement in research and development in this field. Although Trichoderma is considered a well-known fungal genus, it still attracts the attention of large companies, universities, and research institutes around the world. [ABSTRACT FROM AUTHOR]

Dollar spot caused by Clarireedia spp. (formerly Sclerotinia homoeocarpa) is an economically destructive fungal disease of turfgrass that can significantly compromise turf quality, playability, and aesthetic value. Fungicides are frequently used to manage the disease but are costly and potentially unfavorable to the environment. Repeated use of some active ingredients has resulted in reduced efficacy on C. jacksonii causing dollar spot in cool-season turfgrasses in the US. Experiments were conducted to study fungicide sensitivity of Clarireedia spp. as well as to develop alternatives to fungicides against dollar spot on warm-season turfgrass in Georgia. First, 79 isolates of Clarireedia spp. collected across the state were tested on fungicide-amended agar plates for their sensitivity to thiophanate-methyl (benzimidazole) and propiconazole (dimethyl inhibitor). Seventy-seven isolates (97.5%) were sensitive (0.001 to 0.654 μg/mL) and two isolates (2.5%) were found resistant (>1000 μg/mL) to thiophanate-methyl. However, in the case of propiconazole, 27 isolates (34.2%) were sensitive (0.005 to 0.098 μg/mL) while 52 isolates (65.8%) were resistant (0.101 to 3.820 μg/mL). Next, the efficacy of three bio- and six synthetic fungicides and ten different combinations were tested in vitro against C. monteithiana. Seven bio- and synthetic fungicide spray programs comprising Bacillus subtilis QST713 and propiconazole were further tested, either alone or in a tank mix in a reduced rate, on dollar spot infected bermudagrass ‘TifTuf’ in growth chamber and field environments. These fungicides were selected as they were found to significantly reduce pathogen growth up to 100% on in vitro assays. The most effective spray program in growth chamber assays was 100% B. subtilis QST713 in rotation with 75% B. subtilis QST713 + 25% propiconazole tank mix applied every 14 days. However, the stand-alone application of the biofungicide B. subtilis QST713 every seven days was an effective alternative and equally efficacious as propiconazole, suppressing dollar spot severity and AUDPC up to 75%, while resulting in acceptable turf quality (>7.0) in field experiments. Our study suggests that increased resistance of Clarireedia spp. to benzimidazoles and dimethyl inhibitors warrants continuous surveillance and that biofungicides hold promise to complement synthetic fungicides in an efficacious and environmentally friendly disease management program.

Rice blast caused by the Magnaporthe oryzae pathogen is a major disease in this crop, and may cause devastating losses. This study aimed to investigate the profile of Waitea circinata mycorrhiza volatile compounds in antagonism to M. oryzae, under different growth periods and temperatures, using a completely randomized design. Volatile organic compounds were extracted by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry, while multidimensional scaling was used to compare the produced volatile organic compounds. The main compounds responsible by the antagonism to M. oryzae were longifolene, trans-β-farnesene, (Z)-α-bisabolene and δ-amorphene, which can be used as biofungicides and incorporated into rice blast management strategies.

Alternaria blight, caused by Alternaria brassicae, is a major disease affecting mustard crops, leading to significant yield losses. Traditional chemical fungicides have been extensively used to manage this disease, but concerns over environmental pollution, development of resistance, and potential health hazards have shifted the focus towards alternative strategies. Biofungicides, derived from natural sources such as microbes, plants, and their products, have emerged as promising alternatives for managing Alternaria blight while ensuring sustainability and minimal environmental impact. The purpose of the present study was the use of biofungicides as a more sustainable alternative for managing Alternaria blight in mustard at Amity University, located in Noida, Uttar Pradesh. The organic treatment included FYM, Neem oil, Trichoderma viride in different combinations. Pusa Sag1 variety was used for the field study. The present findings revealed the significance differences were recorded in different growth stages of mustard among the various treatment tested. It has been found that minimum disease incidence was observed in T5-Trichoderma viride + FYM + Neem oil (3%), followed by T4Trichoderma viride + Neem oil (13%), T3Trichoderma viride (15%), T2Neem oil(28%), T1FYM(28%). Biofungicides holds great promise for sustainable disease control while minimizing environmental risks and promoting agricultural resilience.

Chitosan is an organic compound derived from the shells of sea shells, and has wide application in agricultural production. The main effect of chitosan is a biofungicidal effect on many plant diseases. In addition, chitosan has a good effect against stressful conditions during plant growth and development. Applying chitosan increases the quality of fruits and increases storage life, which is especially important for small fruits (strawberry, raspberry, blackberry, blueberry). As chitosan is a natural compound, it is licensed for use in organic agricultural production and is an important preparation for use in organic farming. At EU level it is designated as a preparation based on a basic substance, in accordance with EC standard 1107/2009.

Chitosan is an organic compound derived from the shells of sea shells, and has wide application in agricultural production. The main effect of chitosan is a biofungicidal effect on many plant diseases. In addition, chitosan has a good effect against stressful conditions during plant growth and development. Applying chitosan increases the quality of fruits and increases storage life, which is especially important for small fruits (strawberry, raspberry, blackberry, blueberry). As chitosan is a natural compound, it is licensed for use in organic agricultural production and is an important preparation for use in organic farming. At EU level it is designated as a preparation based on a basic substance, in accordance with EC standard 1107/2009.

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)