Search Results (96)

Essential oils (EOs) are widely recognized for their antifungal properties, but their efficacy against specific phytopathogenic fungi associated with banana (Musa paradisiaca) rot remains underexplored. This study aimed to evaluate the antifungal potential of EOs from Origanum vulgare, Salvia rosmarinus, Syzygium aromaticum, Thymus vulgaris, Cinnamomum verum, and Ocimum basilicum against five fungal species isolated from infected banana peels. Fungal isolates were obtained using PDA medium supplemented with chloramphenicol and were purified by weekly subculturing. Morphological and microscopic characterization was complemented by molecular identification based on ITS sequencing and phylogenetic reconstruction using Neighbor-Joining and UPGMA methods in MEGA v11. In vitro and ex vivo antifungal assays were performed at EO concentrations ranging from 200 to 1000 ppm. Thyme oil exhibited the strongest inhibitory effect, with complete growth suppression at 1000 ppm. Cinnamon and oregano also demonstrated effective inhibition at 600 ppm, while clove, rosemary, and basil were markedly less effective. Statistical analysis confirmed significant effects of EO type and concentration on fungal growth (p < 0.001). Molecular results showed strong phylogenetic support for isolate identification, with bootstrap values above 93% in most clades. These findings support the selective use of specific EOs as sustainable alternatives to synthetic fungicides in the postharvest management of banana diseases and provide a molecularly supported basis for their targeted application in integrated control strategies. Full article

Fruit and vegetable production is often impacted by microbial pathogens that compromise the quality of produce and lead to significant economic losses at the postharvest stages. Due to their efficacy, agrochemicals are widely applied in disease management; nevertheless, this practice has led to the appearance of microbial strains resistant to these types of agrochemicals. Additionally, there is growing concern among consumers about the presence of these chemical residues in fruits and the negative impacts they cause on multiple ecosystems. In response, there is a growing need for safe, effective, green, and sustainable disease control technologies. Bionanocomposites, with their unique ability to combine nanomaterials and biopolymers that have attractive properties, represents a promising alternative for postharvest disease control. These technologies allow for the development of functional coatings and films with antimicrobial, antioxidant, and barrier properties, which are critical for extending shelf life and preserving fruit quality. Recent advances have demonstrated that integrating nanoparticles, such as ZnO, TiO₂, Ag, and chitosan-based nanosystems, into biopolymeric matrices, like alginate, pectin, starch, or cellulose, can enhance mechanical strength, regulate gas exchange, and control the release of active agents. This review presents systematized information that is focused on the creation of coatings and films based on bionanocomposites for the management of disease in fruits and vegetables. It also discusses the use of diverse biopolymers and nanomaterials and their impact on the quality and shelf life of fruits and vegetables. Full article

Rhizopus stolonifer causes soft rot disease in strawberry and is considered one of the most destructive pathogens affecting strawberries worldwide. This study investigated the efficacy of three atmospheric non-thermal plasmas (NTPs) consisting of gliding arc (GA), Tesla coil (TC) and dielectric barrier discharge (DBD) for controlling R. stolonifer infection. Fungal mycelial discs were exposed to these plasmas for 10, 15 or 20 min, whereas conidial suspensions were treated for 1, 3, 5 or 7 min. Morphological alterations following non-thermal plasma exposure were studied using scanning electron microscopy (SEM). Exposure to GA and DBD plasmas for 20 min completely inhibited mycelial growth. SEM analysis revealed significant structural damage to the mycelium, sporangia and sporangiospores of treated samples compared to untreated controls. Complete inhibition of sporangiospore germination was achieved with treatments for at least 3 min for all NTPs. Pathogenicity assays on strawberry fruit showed that 15 min exposure to any of the tested NTPs completely prevented the development of soft rot disease. Importantly, NTP treatments did not adversely affect the external or internal characteristics of treated strawberries. These findings suggest that atmospheric non-thermal plasmas offer an effective approach for controlling R. stolonifer infection in strawberries, potentially providing a non-chemical alternative for post-harvest disease management. Full article

Bananas, one of the most widely consumed tropical fruits in the world, are susceptible to attack by the anthracnose fungus Colletotrichum musae during the post-harvest period. Currently, fungus control is generally based on the use of chemical products, often applied a few days before harvest, which could lead to a risk of residues in the fruit, thus creating a high demand for fresh and organic fruits. Therefore, essential oils present an emerging alternative for the treatment of anthracnose. Here, we evaluated the chemical composition and potential of Morinda citrifolia essential oil as a preventive and curative measure to control C. musae in bananas, also considering the quality of the fruit. In addition, computational docking analysis was conducted to predict potential molecular interactions between octanoic and butanoic acids and the enzyme Tyrosine tRNA, as a potential target for the M. citrifolia essential oil fungicide actions. We also evaluated the essential oil’s safety for beneficial organisms such as the fungus Trichoderma asperellum and the ladybugs Eriopis connexa Germar and Coleomegilla maculata DeGeer. Initially, in vitro growth inhibition tests were performed with doses of 10.0, 30.0, and 50.0 µL/mL of M. citrifolia essential oil, as well as an assessment of the phytotoxic effects on the fruit. Subsequently, using non-phytotoxic doses, we evaluated the effect of the essential oil as a preventive and curative measure against anthracnose and its impact on fruit quality. Our results showed that octanoic, butanoic, and hexanoic acids were the major compounds in M. citrifolia essential oil, inhibiting the growth of C. musae by interacting with the Tyrosine tRNA enzyme of C. musae. The non-phytotoxic dose on the fruit was 10 µL/mL of noni essential oil, which reduced C. musae growth by 30% when applied preventively and by approximately 25% when applied as a curative measure. This significantly reduced the Area Under the Disease Progress Curve without affecting the fruit weight, although there was a slight reduction in °Brix. The growth of non-target organisms, such as T. asperellum and the insect predators Co. maculata and E. connexa, was not affected. Collectively, our findings suggest that M. citrifolia essential oil is a promising alternative for the prevention and control of anthracnose in banana fruit caused by C. musae, without adversely affecting its organoleptic characteristics or non-target organisms. Full article

Postharvest losses of Solanaceae crops, which include potatoes (Solanum tuberosum), tomatoes (Solanum lycopersicum), bell peppers (Capsicum annuum), and others, are one of the major challenges in agriculture throughout the world, impacting food security and economic viability. Agrochemicals have been successfully employed to prevent postharvest losses in agriculture. However, the excessive use of agrochemicals may cause detrimental effects on consumer health, the emergence of pesticide-resistant pathogens, increased restrictions on existing pesticides, environmental harm, and the decline of beneficial microorganisms, such as natural antagonists to pests and pathogens. Hence, there is a need to search for a safer and more environmentally friendly alternative. Microbial antagonists have gained more attention in recent years as substitutes for the management of pests and pathogens because they minimize the excessive applications of toxic substances while providing a sustainable approach to plant health management. However, more research is required to make microbial agents more stable and effective and less toxic before they can be used in commercial settings. Therefore, research is being conducted to develop new biological control agents and obtain knowledge of the mechanisms of action that underlie biological disease control. To accomplish this objective, the review aims to investigate microbial antagonists’ modes of action, potential future applications for biological control agents, and difficulties encountered during the commercialization process. We also highlight earlier publications on the function of microbial biological control agents against postharvest crop diseases. Therefore, we can emphasize that the prospects for biological control are promising and that the use of biological control agents to control crop diseases can benefit the environment. Full article

Peach fruit faces severe postharvest losses due to thin epidermis and susceptibility to Rhizopus stolonifer-induced soft rot. Chemical control risks residue and resistance issues, demanding eco-friendly alternatives. This study elucidated the mechanism by which trans-2-hexenal (E2H) mitigated postharvest soft rot caused by Rhizopus stolonifer in peach (Prunus persica cv. Hujing Milu) fruit. The results demonstrated that E2H treatment significantly delayed lesion expansion by 44.7% and disease incidence by 23.9% while effectively maintaining fruit quality by delaying firmness loss, reducing juice leakage, and suppressing malondialdehyde (MDA) accumulation. E2H treatment upregulated phenylpropanoid pathway gene expression, enhancing key phenylpropanoid metabolism enzymes activities (phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), polyphenol oxidase (PPO), peroxidase (POD)), leading to the increase of total phenolics by 7.9%. E2H treatment analysis revealed significant enhancements in both chitinolytic activity (CHI) and β-1,3-glucanase (GLU) activity by 85.7% and 12.9%, indicating potentiation of the enzymatic defense system. Concurrently, E2H treatment could improve the redox modulation capacity of peach fruits through promoting catalytic efficiency of redox-regulating enzymes, increasing the accumulation of ascorbic acid (AsA) by 8.1%, inhibiting the synthesis of dehydroascorbic acid (DHA) by 18.6%, as well as suppressing the biosynthesis of reactive oxygen species (ROS). These coordinated enhancements in pathogenesis-related proteins (CHI, GLU), phenylpropanoid metabolism activation, and antioxidant systems are strongly associated with E2H-induced resistance against Rhizopus stolonifer, though contributions from other factors may also be involved. Full article

Anthracnose is a disease caused by phytopathogenic fungi such as Colletotrichum siamense that attacks plants and fruits causing great postharvest losses. Different alternatives for the control of this fungus have been studied. In the present study, we evaluated the in vitro antifungal activity of the methanolic extracts of Baccharis glutinosa (ExB) and Jacquinia macrocarpa (ExJ) individually, as well as in combination with chitosan (CS), along with their toxicity in different models. Using the radial growth technique, it was observed that the mycelial development of C. siamense was altered and reduced during exposure to the different treatments evaluated during the first hours of incubation, indicating a fungistatic effect. While the cell viability, by colorimetric assay using the XTT salt, showed alteration since the chitosan reduced proliferation by 50%, while the plant extracts and their mixtures with chitosan reduced approximately 40% indicating cell damage, which was confirmed by fluorescence microscopy. In addition, toxicity tests demonstrated that the J. macrocarpa extract significantly affected the germination percentage of Lactuca sativa seeds, whereas radicle length was reduced in all treatments except for chitosan. The larval survival test for Artemia salina with the extracts indicated their potential toxicity by causing up to 60% mortality. The results indicate that ExB and ExJ mixed with CS are a good option for controlling C. siamense; however, at the concentrations used, they exhibit a toxic effect on the evaluated models. Full article

Postharvest fungal infections, particularly by Botrytis cinerea, can cause up to 50% losses in fruits and vegetables, and the overuse of synthetic fungicides has led to resistant pathogen strains. We hypothesized that hexane (Hex) and methanolic (MeOH) extracts from peanut (P) and pecan nut (PN) shells possess antifungal properties effective against B. cinerea in strawberries. To test this, we conducted both in vitro and ex vivo assays using strawberries inoculated with B. cinerea, comparing two controls (T0: water; T1: commercial synthetic fungicide) with four treatments—Hex-P, MeOH-P, Hex-PN, and MeOH-PN—at 1000 and 2000 ppm (in vitro) and 4000 ppm (ex vivo). Total phenolic content (TPC) and antioxidant activity (AA) were also measured. MeOH-P and Hex-PN extracts at 2000 ppm significantly inhibited fungal mycelial growth in vitro. In ex vivo assays, MeOH-P reduced both disease incidence and severity comparably to the synthetic fungicide. MeOH-PN exhibited the highest TPC and AA. These findings support the potential use of MeOH-P extract as a natural alternative to synthetic fungicides for controlling B. cinerea in strawberries during postharvest storage. Full article

Black spot is a major postharvest disease of cherry tomatoes, caused by Alternaria alternata. This causes economic losses and storage challenges, so researchers are exploring alternative methods. The biological control of fruits and vegetables using antagonistic bacteria and yeasts is currently a research hotspot. Initially, the biological control impact of Bacillus velezensis T3 on cherry tomato black spot was investigated. Disease defense, scavenging reactive oxygen species, and antioxidant-related enzymes were determined during different storage periods. The relative gene expressions of these enzymes were also confirmed using RT-qPCR. The results showed that B. velezensis T3 reduced the incidence of black spot disease in cherry tomatoes. The growth of A. alternata was suppressed by B. velezensis T3 cell-free filtrate both in vitro and in vivo. In addition, B. velezensis T3 induced the activities of disease resistance-related enzymes such as polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), β-1,3-glucanase (GLU), and chitinase (CHI), and the activities of the ROS-related enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), and reduced the rate of O₂⁻ production and H₂O₂, and MDA content of cherry tomatoes. This approach offers a promising alternative for extending shelf life, though further studies are needed to fully characterize its effects on fruit quality. Full article

Due to their secondary metabolite content, plant extracts are an alternative method for controlling pathogenic organisms in agriculture and post-harvest operations. Botrytis cinerea and Pseudomonas syringae are among the causative agents of diseases and losses in agricultural production. The species Larrea tridentata is abundant in the arid and semi-arid zones of Mexico and has no defined use; however, it contains secondary metabolites with microbicidal potential that could aid in biological control and enhance its harvest status. Growth inhibition (halo) of B. cinerea and P. syringae was evaluated by applying alcoholic extract of L. tridentata leaves at doses of 50, 100, 250, 500, 750, 1000, and 2000 µg mL⁻¹ in vitro, using poisoned medium and potato dextrose agar for the fungus and the agar well method for the bacteria, in a completely randomized design with five replicates. The flavonoids quercetin, apigenin, narigenin, kaempferol, and galangin were identified as possible agents of microbicidal activity. The extract inhibited the growth of B. cinerea from 100 µg mL⁻¹ and completely inhibited it with 1000 and 2000 µg mL⁻¹. For P. syringae, inhibition was observed from 250 µg mL⁻¹, demonstrating that the higher the concentration, the greater the growth inhibitory effect. The secondary metabolite content of the L. tridentata extract is sufficient to have an impact on microorganisms with economic impact in agriculture. Full article

Soft rotting caused by Rhizopus stolonifer is one of the most important postharvest decays in Kokei No. 14 organic sweet potato roots. While various methods have been explored for controlling this pathogen, there remains a need for effective, safe, and applicable alternatives, particularly using essential oils (EOs). This study evaluated the efficacy of EOs, specifically carvacrol, thymol, and thyme oil, in controlling Rhizopus soft rot. We conducted both in vitro and in vivo tests to assess their effects on fungal mycelial growth, spore germination, and the incidence and severity of soft rot in sweet potatoes, along with quality evaluations of the roots. The results indicated that the vapor phase of carvacrol, thymol, and thyme oil was more effective than the contact phase in inhibiting fungal growth and spore germination. In vivo tests revealed that all three EOs significantly reduced the incidence and severity of soft rot, with thymol and thyme oil at 300 mg/L, and carvacrol at 500 mg/L being the most effective. Quality assessments showed minimal impact on properties such as firmness, weight loss, color, starch, carotenoids, and flavonoids, although residual odors increased. GC/MS analysis confirmed that thyme oil contained high levels of both thymol and carvacrol, along with other antimicrobial compounds, suggesting that the cumulative activity of these volatile compounds enhanced their bacteriostatic effects. Thyme oil demonstrated greater efficacy in reducing soft rot development compared to its individual components, making it a promising biofumigant for controlling postharvest diseases in Kokei No. 14 organic sweet potato roots. These findings emphasized the potential for using thyme oil as a safe and effective approach to managing postharvest decay. Full article

Postharvest decay of vegetables and fruits presents a significant threat confronting sustainable food production worldwide, and in the recent times, applying synthetic fungicides has become the most popular technique of managing postharvest losses. However, there are concerns and reported proofs of hazardous impacts on consumers’ health and the environment, traceable to the application of chemical treatments as preservatives on fresh produce. Physical methods, on the other hand, cause damage to fresh produce, exposing it to even more infections. Therefore, healthier and more environmentally friendly alternatives to existing methods for managing postharvest decays of fresh produce should be advocated. There is increasing consensus that utilization of biological control agents (BCAs), mainly fungi, represents a more sustainable and effective strategy for controlling postharvest losses compared to physical and chemical treatments. Secretion of antifungal compounds, parasitism, as well as competition for nutrients and space are the most common antagonistic mechanisms employed by these BCAs. This article provides an overview of (i) the methods currently used for management of postharvest diseases of fresh produce, highlighting their limitations, and (ii) the use of biocontrol agents as an alternative strategy for control of such diseases, with emphasis on fungal antagonists, their mode of action, and, more importantly, their advantages when compared to other methods commonly used. We therefore hypothesize that the use of fungal antagonists for prevention of postharvest loss of fresh produce is more effective compared to physical and chemical methods. Finally, particular attention is given to the gaps observed in establishing beneficial microbes as BCAs and factors that hamper their development, particularly in terms of shelf life, efficacy, commercialization, and legislation procedures. Full article

Postharvest diseases cause considerable losses of fruits and vegetables during transportation and storage, and synthetic fungicides are the first option for their prevention. However, promising alternatives to chemical fungicides are currently available, and several post-harvest diseases can be controlled using microbial antagonists. This study utilised a comprehensive methodology to assess the antagonistic and synergistic interactions between four yeasts and two bacteria in conjunction with sodium bicarbonate (SB) during the treatment of sweet cherries and plums. The aim of this study was to evaluate the effects of microbial antagonists and sodium bicarbonate on fruits. The in situ treatments showed a protective effect exerted by the antagonists P. guillermondii and H. uvarum, and their combination with SB. However, in vivo studies did not indicate enhanced efficacy when combined with this compound. In conclusion, the use of microbial antagonists in conjunction with SB has been successful in preventing post-harvest rot of cherries and plums. Tests conducted on live organisms have shown that microbial antagonists are viable alternatives to synthetic fungicides for the control of stone fruit rot. Full article

Postharvest fungal diseases are the main cause of economic losses in lemon production. The continued use of synthetic fungicides to control the diseases favors the emergence of resistant strains, which encourages the search for alternatives. The aim of this study was to assess the efficacy of metallic nanoparticles (NPs) as antifungal agents against local isolates of Penicillium digitatum and Penicillium italicum, each of them in a fungicide-sensitive and -resistant version, and a Geotrichum citri-aurantii isolate. NPs of ZnO, CuO, and Ag were synthesized and characterized by spectroscopy and microscopy, presenting average sizes < 25 nm and spherical shapes. ZnO-NPs did not present antifungal activity at the assayed conditions, while the minimum fungicidal concentrations (MFCs) were 1000 and 10 µg mL⁻¹ for CuO-NPs and Ag-NPs, respectively. The NPs’ antimicrobial action included conidial membrane permeability and strong intracellular disorganization. Moreover, the Ag-NPs reduced green mold incidence on inoculated lemons when applied to the fruit. Taken together, Ag-NPs were effective in inhibiting both fungicide-sensitive and -resistant isolates of the main lemon postharvest pathogens, suggesting their potential use as an alternative approach. Full article

Sour rot, caused by Geotrichum citri-aurantii, is a significant post-harvest disease in citrus, resulting in economic losses due to the lack of effective fungicides. This study investigates the antifungal activity of citrus essential oils in controlling sour rot in Tahiti acid lime fruits. Essential oils were extracted via hydrodistillation with chemical composition analyzed by CG-MS and tested in vitro and in vivo. In vitro assays evaluated mycelial growth inhibition at 2 to 32 µL mL⁻¹ concentrations. In vivo trials involved preventive and curative treatments on artificially inoculated fruits stored at 25 °C ± 2, and the results showed that Pera IAC sweet orange oil, at 32 µL mL⁻¹, reduced disease severity by 96% in curative treatments. In contrast, Late IAC 585 willowleaf mandarin oil demonstrated moderate inhibition (44%) at the highest concentration in vitro. The oils did not affect key fruit quality parameters such as juice yield and total soluble solids. These findings suggest that citrus essential oils could be natural alternatives to synthetic fungicides for post-harvest sour rot management, combining effectiveness with maintaining fruit quality. Full article