Search Results (160)

Background and Aim: Mango (Mangifera indica) is a globally important fruit crop whose productivity is repeatedly threatened by foliar diseases such as anthracnose, bacterial canker, powdery mildew, die-back, and sooty mould. Although deep learning has rapidly advanced automated leaf-disease diagnosis, recently reported accuracies on the MangoLeafBD benchmark are approaching saturation, and many studies still rely on random data splits that may inflate performance through leakage of duplicate or near-duplicate images. This study aimed to develop and rigorously evaluate a leakage-aware, deployment-oriented deep learning framework for the complete eight-class MangoLeafBD task. Methods: Three modern transfer-learning backbones—EfficientNetB0, MobileNetV3Large, and ConvNeXtTiny—were fine-tuned using a two-stage training strategy on a group-aware data partition. Duplicate and near-duplicate images were detected with cleaned filename stems, average hashing (aHash), and difference hashing (dHash) and grouped before splitting to guarantee zero cross-partition overlap. The strongest models were combined through probability-level soft voting. Robustness was further assessed using 5-fold StratifiedGroupKFold cross-validation. Explainability was examined with Gradient-weighted Class Activation Mapping (Grad-CAM), deployment suitability was characterized through CPU latency benchmarking, and the framework was operationalized as a publicly accessible web-based diagnostic system. Results: EfficientNetB0 achieved the highest performance under the leakage-controlled protocol, reaching 99.50% accuracy and 99.50% weighted F1-score on the 599-image group-aware test set. The heterogeneous soft-voting ensemble matched EfficientNetB0 but did not exceed it, indicating that the ensemble gains reported in earlier studies may partly reflect optimistic split conditions. Five-fold grouped cross-validation confirmed stability, yielding a mean accuracy of 99.63% (SD = 0.20%) and a mean weighted F1 of 99.62% (SD = 0.20%). Grad-CAM visualizations showed that the model attended to biologically meaningful lesion regions across all eight classes, and CPU benchmarking produced a mean single-image latency of 25.3 ms (p95 = 27.6 ms) with batch throughput scaling up to 166.5 images per second. Conclusions: The proposed framework demonstrates that a compact, leakage-aware EfficientNetB0 model can match the accuracy of more complex hybrid CNN–transformer architectures while remaining interpretable and deployable on commodity CPU hardware. By coupling group-aware evaluation, explainable AI, latency benchmarking, and a publicly accessible web application, the study advances reproducible, deployment-ready precision agriculture research and offers a more rigorous benchmarking protocol for future mango leaf disease classification studies. Full article

Global avocado production exceeds 10 million tons annually. Among the diseases affecting avocado fruit, anthracnose is one of the most significant, causing black lesions and fruit decay that can result in yield losses of 20–30%. To facilitate the early detection of anthracnose, this study proposes a computer vision-based approach. A dataset containing 2218 images of Fuerte avocados was first developed, comprising 1730 healthy samples and 488 anthracnose-infected samples after the labeling process. In the experimental phase, several convolutional neural network (CNN) models with varying depths (3, 4, 5, and 6 layers) were designed and evaluated. These models were subsequently integrated into different weighted ensemble configurations, where the best performance was achieved by the ensemble combining all four individual CNNs. The proposed weighted ensemble was compared against widely used state-of-the-art architectures, including VGG-16, ResNet-18, and MobileNetV2. Experimental results demonstrated the effectiveness of the proposed approach, achieving an F1-score of 0.9052, outperforming VGG-16 (0.8283), ResNet-18 (0.7328), and MobileNetV2 (0.7320). Full article

Postharvest rot caused by Neopestalotiopsis rosae severely threatens strawberry production globally. Here, a novel species of Streptomyces was isolated and identified through polyphasic taxonomy, for which we propose the name Streptomyces hanimojiang sp. nov. AMJ-169. Its volatile organic compounds (VOCs) inhibited N. rosae hyphal growth by 70 ± 3.81%, with (1S)-(-)-α-pinene identified as the key antifungal component (EC₅₀ = 0.018 mL·L⁻¹). Fumigation with 6× EC₅₀ α-pinene reduced fruit rot by 97.52% in a concentration-dependent manner. SEM observations showed that α-pinene caused severe hyphal damage and suppressed pathogen colonization on fruit surfaces. Transcriptomic analysis further indicated that α-pinene treatment was associated with redox regulation, glutathione metabolism, phenylpropanoid metabolism, and carbon-metabolism-related responses in strawberry fruit. These findings suggest that α-pinene controls postharvest anthracnose through direct antifungal activity on fungal hyphae together with host-associated physiological regulation, highlighting its potential as a sustainable postharvest biocontrol candidate. Full article

An eco-friendly microemulsion biofungicide derived from Allamanda cathartica was developed for the control of papaya anthracnose caused by Colletotrichum gloeosporioides. The formulation was prepared by blending surfactants, carrier oil, and water and optimized using ternary phase diagrams to identify stable microemulsion systems. All selected formulations exhibited surface tension values ranging from 29 to 31 mN/m, while particle sizes ranged from 51.79 to 1801.05 nm. The optimized formulation, coded as AM8, consisted of 35% Allamanda concentrated liquid crude extract (ACLCE), 26% water, 13% alkyl polyglucoside surfactant, and 26% dimethylamide oil. Papaya fruits coated with the formulations showed significant reductions (p < 0.05) in anthracnose incidence caused by C. gloeosporioides. Control fruits treated with water showed 75% disease incidence, whereas fruits treated with benomyl showed 42% disease incidence. Disease incidence, severity, and disease index decreased with increasing formulation concentration, and fruits treated with the eight formulations at 10% concentration exhibited significantly lower disease incidence (0–17%) and disease index (0–17%), with disease severity consistently scored as zero. The Allamanda formulation demonstrated strong antifungal activity with EC₅₀ and EC₉₅ values of 1.839 and 7.067 mg/mL (w/v), respectively, at the 95% confidence level. The optimized formulation AM8 remained stable for up to one year and showed superior disease control performance compared with the conventional fungicide benomyl. In addition, the formulation maintained fruit quality by preserving firmness, peel color, and soluble solids concentration, thereby extending papaya shelf life up to 30 days without adversely affecting the natural ripening process. These findings demonstrate the potential of Allamanda-based microemulsion formulations as sustainable biofungicides for postharvest control of papaya anthracnose and provide a promising alternative to conventional synthetic fungicides. Full article

Anthracnose, caused by Colletotrichum sp. isolate XCC1, is a major postharvest disease causing significant quality deterioration and economic losses in ‘Cat Chu’ mango during storage. This study evaluated the effectiveness of sodium alginate–carboxymethyl cellulose (SA-CMC) coating with natamycin for controlling anthracnose and maintaining postharvest fruit quality. Mango fruits were treated with the SA-CMC-Natamycin coating and stored under controlled conditions (25 ± 2 °C; RH = 60 ± 5%) to assess disease development, plant defense enzyme activities, and fruit quality attributes. Natamycin inhibited spore germination of Colletotrichum sp. isolate XCC1 with a Minimal Inhibitory Concentration (MIC) of 6.25 µg mL⁻¹. The SA-CMC-Natamycin coating significantly reduced anthracnose development, resulting in a three-fold decrease in disease incidence and a 3.86-fold reduction in disease severity compared with the control on day 9 of storage. However, the persistence of the treatment was limited since no significant disease incidence reduction was observed after 15 days. The treatment also enhanced chitinase (CHI) and β-1,3-glucanase (GLU) activities and increased phenolic compound accumulation. In addition, the coating delayed fruit ripening by maintaining firmness, titratable acidity (TA), vitamin C, and chlorophyll while suppressing increases in color change and total soluble solids (TSS). These results demonstrate that SA-CMC-Natamycin coating is a promising eco-friendly strategy for controlling anthracnose and preserving postharvest quality of ‘Cat Chu’ mango. Full article

Muskmelon (Cucumis melo L.) is an economically important crop that remains highly susceptible to destructive fungal diseases, including gummy stem blight, downy mildew, Fusarium wilt, and anthracnose. Although fungicides and resistant cultivars are widely used, reliance on chemical control raises concerns regarding environmental safety, food quality, and the emergence of fungicide-resistant pathogen populations. Consequently, microbial biopesticides, particularly Bacillus species, have attracted increasing attention as sustainable alternatives. In this study, muskmelon plants exhibiting leaf wilting, chlorosis, and stem yellowing were collected from Guangming Farm in Wufeng, Taichung, Taiwan, and associated pathogens were isolated from stem tissues and identified to determine the causal agent of these symptoms. In addition, the biocontrol efficacy of Bacillus subtilis strain MCLB2 against melon fruit rot, as well as its underlying mechanisms, was evaluated. Pathogenicity assays confirmed that isolate F01 was the causal agent. Based on morphological characteristics and internal transcribed spacer (ITS) sequence analysis, this isolate showed 99.8% identity to Fusarium pernambucanum URM 7559 (GenBank accession no. NR_163754), and phylogenetic analysis further placed it within the Fusarium incarnatum-equiseti species complex (FIESC). Antagonistic assays demonstrated that B. subtilis MCLB2 significantly inhibited mycelial growth and suppressed the spore germination of F. pernambucanum. In addition, culture filtrates of strain MCLB2 effectively reduced Fusarium-induced fruit rot in melon and disrupted fungal cellular respiration. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis revealed that the strain produced surfactin-family lipopeptides. In conclusion, B. subtilis MCLB2 exhibits potential as a sustainable biocontrol agent for managing Fusarium fruit rot in melon, likely through surfactin-mediated disruption of fungal cellular respiration. Full article

Mango (Mangifera indica L.), a major tropical fruit crop, suffers severe anthracnose damage caused by Colletotrichum spp., and traditional chemical control has environmental and food safety risks, with plant-microbe interaction-based biological control as a sustainable alternative. However, the regulatory role of phyllosphere microbiota in the tripartite interactions among mango, beneficial microbes and Colletotrichum remains unclear. This study explored phyllosphere microbiota’s function in mango resistance to Colletotrichum and clarified the biocontrol mechanism of key beneficial isolates. We found Colletotrichum infection significantly reshaped mango leaf endophytic and epiphytic microbial communities, enriching Burkholderia, Acinetobacter, Bacillus and other dominant genera. We isolated a B. subtilis strain L-1 from the epiphytic microbiota that was 18-fold enriched in Colletotrichum-infected mango leaves. This strain exhibited potent antagonistic activity against Colletotrichum siamense with a relative inhibition rate of 82.10%, and delivered 79.77% biocontrol efficacy on mango leaves via two synergistic pathways: inhibiting pathogen spore germination and penetration by producing antimicrobial secreted metabolites and volatile organic compounds, and enhancing host disease resistance. Our findings advance the understanding of plant-phyllosphere microbiota-pathogen tripartite interactions and provide elite microbial resources for sustainable anthracnose management. Full article

Feijoa fruits are known for their pronounced post-harvest ripening. Phytopathogen-infected specimens pose a significant risk to storage stability and overall fruit quality. Early detection and removal of defective fruits during the initial storage stages are critical for maintaining market value and preventing the spread of disease. In this study, we analyze how the multispectral reflectance properties of the feijoa surface change in response to various defects. ‘Superba’ cultivar fruits were selected, including healthy controls and samples exhibiting bruises, anthracnose, stink bug damage, tissue suberization, and gray mold. Biochemical analyses were conducted to measure the levels of organic acids, sugars, ascorbic acid, and total polyphenols. Multispectral imaging was performed with a 12-channel camera operating in the 400–1000 nm wavelength range. Results showed that the fruits affected by gray mold had the lowest concentrations of malic and citric acids but the highest levels of succinic acid. Fruits with anthracnose or insect damage exhibited the highest sugar content. Distinct differences in spectral reflectance were observed between healthy and affected areas of fruit. Based on these findings, an image processing algorithm for defective fruit detection was developed. Full article

Chilli is a major horticultural crop in tropical and subtropical regions that contributes substantially to the global culinary and economic sectors. However, anthracnose remains one of the most destructive diseases, causing severe losses in both field and stored fruits. Current management strategies offer limited long-term effectiveness, highlighting the need for sustainable alternatives. This study developed nanoemulsions (NEs) from Garcinia atroviridis fruit extract and evaluated their biocontrol potential against Colletotrichum capsici alone and in combination with Trichoderma harzianum. Two formulations, NE4 and NE7, exhibited good thermostability without phase separation at 25 and 54 °C, with droplet sizes of 135.1 and 124.1 nm, respectively, and were non-phytotoxic to chilli seedlings. In vitro, the nanoemulsions significantly suppressed C. capsici mycelial growth (62%) compared to the crude extract. Under rain shelter conditions, NE integrated with T. harzianum (T7 and T8) was highly effective in delaying disease onset and reducing disease severity, achieving 90.07% and 88.37% relative disease reduction, respectively. These treatments also produced the highest marketable yields, comparable to the synthetic fungicide Dithane M-45^® (2 g L⁻¹). In contrast, the untreated control group exhibited an 83% yield loss. The results indicate that nanoemulsions of G. atroviridis fruit extract, particularly when combined with T. harzianum, offer a promising and sustainable biological control option for managing pre-harvest chilli anthracnose. Their incorporation into integrated pest management programmes may reduce dependence on chemical fungicides and support safer chilli production systems. Full article

Mango (Mangifera indica L.), being a climacteric fruit, is highly perishable due to rapid ripening and post-harvest diseases like anthracnose, which significantly shorten its shelf life and limit long-distance sea export. To mitigate these constraints, a chemical-free secondary metabolite-based formulation (SMsF) was developed to delay ripening and control post-harvest anthracnose during storage. The SMsF possesses dual-action properties and is derived from the culture filtrate of Priestia aryabhattai, exhibiting ACC deaminase activity that restricts ethylene formation. It is also rich in antifungal compounds such as vanillic acid, hydroxybenzoic acid, cryptochlorogenic acid, palmitic acid, and BBIT, which inhibit anthracnose development. Additionally, it contains antioxidants including quercetin, coumaryl quinic acid, oleic acid, and acetylglycitin that enhance shelf life and disease resistance. The efficacy of SMsF was evaluated in mango cv. Banganapalli was stored at 12 ± 1 °C and 85–90% relative humidity under simulated reefer conditions (SRC). Integration of gamma irradiation with SMsF provided superior results in disease control and shelf-life extension. The combined treatment maintained higher fruit firmness (0.86 kg cm⁻²), optimal total soluble solids (14.3 °B), desirable acidity (0.22%), and complete suppression of anthracnose (PDI = 0) up to 40 days of storage under SRC compared with the control. The findings conclusively demonstrate that the synergistic application of SMsF and gamma irradiation effectively regulates ripening, enhances fruit quality, and ensures complete disease suppression, thereby significantly extending storage life. This approach holds strong scientific and commercial significance as a sustainable, residue-free, and export-oriented technology capable of improving long-distance transportation, reducing post-harvest losses, and promoting safe mango trade. Full article

Dragon fruit (Hylocereus spp.) is an emerging crop in the tropics and subtropics, but its production is increasingly threatened by diseases that reduce yield and profitability. Early diagnosis of these diseases is crucial for timely intervention, yet visual symptoms often appear only after significant infection has occurred. The study aims to evaluate how optical spectral reflectance can detect dragon fruit diseases and identify the most responsive spectral regions. In this study, six major dragon fruit stem diseases: Neoscytalidium stem canker, stem sunburn, anthracnose, Botryosphaeria stem canker, Bipolaris stem rot, and bacterial soft rot were characterized by the goal of identifying unique spectral signatures for early detection and differentiation of each disease. Seventy-two potted dragon fruit plants of three distinct species were grown under four organic vermicompost treatments (0, 5, 10, 20 tons/acre) in both open-field and high-tunnel conditions together, in a randomized complete block design. A handheld spectroradiometer (350–2500 nm) was used to collect reflectance from the diseased and healthy cladodes (stem segment). Various spectral vegetative indices were computed to identify disease-specific features. The results revealed distinct spectral features for each disease. Infected cladodes consistently exhibited higher reflectance especially in the visible region (400–700 nm) and the near-infrared region (900–2500 nm) of the spectrum than healthy cladodes. The Normalized Difference Vegetative Index (NDVI), Green Normalized Difference Vegetative Index (GNDVI), and Spectral Ratio (SR) spectral indices were significantly higher in healthy plants than in diseased ones, reflecting higher chlorophyll concentration and plant biomass. Conversely, the 1110/810 ratio was lower in healthy plants than in diseased plants, suggesting a more compact internal plant structure. Statistical analysis revealed highly significant differences (p < 0.00001) between healthy and diseased spectra in the Red, Green and NIR regions. Linear Discriminant Analysis(LDA) achieved the highest classification accuracy (OA = 0.642, κ = 0.488), though performance was limited for minority classes. These findings demonstrate that targeted spectral sensing can identify dragon fruit diseases before obvious symptoms emerge. By pinpointing disease-specific spectral indices, our study paves the way for early-warning tools such as targeted multispectral sensors or drone-based imaging that would enable growers to intervene sooner and limit losses. These results highlight the potential for development of UAV-based or portable spectral sensors for large-scale, near real-time disease monitoring in dragon fruit production. Full article

Fungal diseases represent one of the major threats to citrus production, such as anthracnose caused by Colletotrichum gloeosporioides and Fungal Trunk Diseases (FTDs) associated with Botryosphaeriaceae, with Neofusicoccum parvum being the most prevalent species. In response to the need to reduce chemical fungicide use, this study evaluated the antifungal activity of essential oil-based nanoemulsions (N-EOs) as alternative management methods. Seven N-EOs (citronella, clove, fennel, garlic, laurel, lavender and peppermint) were first screened in vitro against multiple isolates of both pathogens through mycelial growth and conidial germination assays. Based on estimated EC₅₀ and EC₉₀ values, clove and garlic N-EOs exhibited the highest inhibitory activity, while lavender displayed intermediate but promising efficacy, particularly against N. parvum. These N-EOs were subsequently evaluated in vivo on lemon fruits inoculated with C. gloeosporioides and on detached lemon twigs inoculated with N. parvum. In vivo assays largely confirmed the in vitro trends, with clove and garlic significantly reducing lesion development. In contrast, lavender displayed limited efficacy under in vivo conditions. The phytotoxic effects at higher concentrations limited the range of applicable doses. Overall, the results suggest that N-EOs, particularly those based on clove and garlic, may offer potential as alternative tools for citrus disease management. However, host tissue interactions, formulation stability, volatility, and validation under field conditions remain critical aspects requiring further investigation. Full article

In response to the growing need for sustainable and safe postharvest strategies, plant essential oils have emerged as promising natural alternatives to synthetic fungicides. Mango (Mangifera indica L.), as a vital tropical fruit, suffers significant postharvest losses due to anthracnose caused by Colletotrichum gloeosporioides. This study investigated the antifungal efficacy of oregano essential oil (OEO) against C. gloeosporioides and its regulatory effects on the postharvest quality of mango fruit. The potent antifungal activity of OEO is demonstrated by its low MIC (0.005%) and MFC (0.01%) against C. gloeosporioides. The antifungal mechanism was primarily attributed to the disruption of plasma membrane integrity of C. gloeosporioides, as indicated by increased propidium iodide uptake, elevated extracellular conductivity, and leakage of cellular proteins. The OEO treatment inhibited peel color transformation, reduced weight loss, maintained firmness, and slowed the increase in the soluble solids content to acidity ratio. Furthermore, OEO enhanced the fruit’s antioxidant capacity by sustaining higher superoxide dismutase activity and suppressing the activities of polyphenol oxidase and peroxidase, leading to a marked reduction in malondialdehyde accumulation. These findings comprehensively demonstrate the dual functionality of OEO as a direct fungicidal agent and a systemic physiological regulator that delays senescence and preserves mango quality. This study underscores the potential of OEO as a sustainable alternative for integrated postharvest management of mango anthracnose, offering insights for its practical application in the fruit industry. Full article

Colletotrichum fructicola is the predominant pathogenic agent responsible for anthracnose in Camellia oleifera. RGS2 is a GTPase-activating protein that negatively regulates G-protein signaling by inactivating Gα subunits. In this study, we characterized the ortholog of CfRGS2 in C. fructicola to explore its pathogenic roles. Seven canonical RGS genes were identified through BLASTp and keyword searches. Conserved domains and subcellular localizations were predicted bioinformatically. A CfRGS2 knockout mutant was generated via overlap-PCR and PEG-mediated transformation, verified by PCR, and complemented by reintroducing the wild-type gene. Phenotypic characterization showed that the growth rates of mutants ΔCfrgs2-1 and ΔCfrgs2-2 were significantly reduced compared with those of the wild-type and complemented strains. On both PDA and minimal medium, the mutant strains exhibited significantly smaller colony diameters of 3.3 cm and 3.1 cm, respectively, relative to the control strains. Moreover, conidiation in the mutants was only 4% of that in the wild-type and complemented strains, and appressorium formation was reduced to 6%, with statistical analyses confirming high significance. Under cell wall stress induced by 400 μg/mL Congo red, the growth inhibition rates of ΔCfrgs2-1 and ΔCfrgs2-2 were 44% and 48%, respectively, significantly higher than those of the control strains. Pathogenicity assays demonstrated that the mutants failed to induce lesions on unwounded leaves and caused 47% and 30% smaller lesion areas on wounded apple fruits, respectively. In summary, C. fructicola possesses seven canonical RGS proteins that regulate G-protein signaling, among which CfRgs2 is implicated in growth, conidiation, the stress response to cell wall perturbation, and virulence. Full article

Monilinia laxa and Colletotrichum fioriniae are major fungal pathogens causing brown rot and anthracnose in stone fruits and shell fruits, leading to significant economic losses. Chemical fungicides are widely applied but can result in resistance development, environmental contamination, and food safety concerns. Biological control using entomopathogenic bacteria (EPB) of the genus Photorhabdus has emerged as an eco-friendly alternative. This study evaluated the in vitro antifungal activity of selected Photorhabdus species (P. kayaii 1723B, P. temperata 3017, P. cinerea 3086, P. laumondii 3196, and P. thracensis 3210) against M. laxa (M3) and C. fioriniae (VV081) using drop-to-drop confrontation and poisoned agar assays. Effects of fermentation time, preparation mode (original vs. centrifuged and filtered), and concentration (5, 10, 20%) were examined. Species-specific inhibition was observed, with Median Inhibition Index values indicated relatively higher antifungal activity for P. thracensis 3210 against M. laxa (0.718) and C. fioriniae (0.552), followed by P. cinerea 3086 (0.643 and 0.552) and P. kayaii 1723B (0.629 and 0.541). Fermentation time and preparation mode influenced antifungal activity in a strain-dependent manner, with longer fermentation periods and original culture preparations generally showing stronger inhibitory trends. Higher concentrations, especially 20%, were often associated with increased inhibition, although the magnitude of these effects varied among strain–pathogen combinations. Overall, these findings demonstrate that the strain- and pathogen-specific nature of antifungal responses in Photorhabdus, supporting their potential as components of targeted biological control strategies rather than uniform broad-spectrum agents. Full article