Search Results (217)

Tolprocarb (TPC), a fungicide primarily used for controlling rice blast, was recently shown to stimulate disease resistance in rice. To elucidate the molecular basis of this immunostimulatory effect, we conducted transcriptomic, metabolic, and field-based analyses focusing on diterpenoid phytoalexins, key antimicrobial and allelopathic compounds in rice. Microarray analysis revealed that TPC treatment induced a broad transcriptional activation of genes involved in phytoalexin biosynthesis, including DPF, a master regulator of diterpenoid metabolism. Consistent with this, LC-MS/MS analyses confirmed the accumulation of momilactones A and B, as well as phytocassanes B, C, and E, in rice leaves after TPC application, a response not observed with conventional resistance inducers such as probenazole or carpropamid. In root tissues under controlled conditions, phytoalexin accumulation was limited, and exudation into the rhizosphere was minimal. However, field experiments showed that TPC treatment led to a transient increase in leaf momilactones around 14 days post-transplanting, followed by increased exudation into the rhizosphere at 21 days. Notably, this increase in root exudation coincided with a reduction in total weed biomass, although weed species composition remained unchanged. These findings suggest that TPC not only enhances rice immunity through phytoalexin induction but may also contribute to weed suppression via allelopathic root exudates in field settings. Our study highlights a dual role for TPC in rice cultivation, boosting disease resistance and suppressing weed growth, and underscores the potential of phytoalexin-focused strategies for integrated crop protection. Full article

Derivatives of 1,2,4-triazole-3-thione exhibit a variety of biological activities, including antimicrobial (e.g., compounds 31d–k, 32d, 36f), antitumor (e.g., 71, 77a–c, 82g, 94h), anti-inflammatory, analgesic (100a, 102, 105), antidiabetic, and antioxidant (104, 138) activity. These compounds can be efficiently synthesized by classical methods (e.g., cyclization of thiosemicarbazides) and/or modern “green” approaches, which allow for obtaining target compounds in high yields (up to 96%). The presence of electron-donating groups (e.g., -OH, -OCH₃) enhances antimicrobial and antitumor activity. Substituents in the aromatic ring (e.g., NO₂, Cl) affect the ability to bind to biological targets such as DNA or enzymes. 1,2,4-triazole-3-thiones can also be used as fungicides and herbicides (e.g., 131), demonstrating high efficiency against phytopathogens. Thus, 1,2,4-triazole-3-thione derivatives are multifunctional compounds with high potential for the development of new drugs and agrochemicals. Their further study and modification can lead to the creation of more effective and safer drugs. Full article

Alternaria leaf blight (ALB) is a major constraint to groundnut production, particularly in North Gujarat, where its incidence has intensified in recent years due to changing climatic conditions. Effective and sustainable disease management requires fungicides that not only suppress the pathogen but also promote plant growth. To identify such options, field experiments were conducted during 2016–2018 to evaluate the bioefficacy of nine fungicides, including five systemic, two contact, and two combination formulations. Among these, propiconazole 25 EC, tebuconazole 25 WG, and carbendazim 50 WP were the most effective in reducing disease intensity and slowing disease progression. The highest pod and haulm yields were recorded in plots treated with tebuconazole 25 WG, followed by propiconazole 25 EC and carbendazim 50 WP. However, the highest cost–benefit ratio was observed with carbendazim 50 WP, followed by propiconazole 25 EC and tebuconazole 25 WG. In addition, propiconazole 25 EC and tebuconazole 25 WG exhibited notable plant growth-promoting effects, enhancing plant height, root length, and chlorophyll content. Based on these findings, the application of propiconazole 25 EC or tebuconazole 25 WG is recommended for the effective and economical management of ALB in groundnut. Full article

Soybean rust, caused by Phakopsora pachyrhizi, is a major foliar disease that often escapes fungicide control, necessitating alternative strategies. We investigated whether phyllosphere arthropods, such as mites and thrips, facilitate the secondary dispersal of the mycoparasitic fungus Simplicillium under controlled conditions. Detached soybean leaves inoculated with P. pachyrhizi were subjected to either arthropod-exposed or arthropod-excluded treatments. Simplicillium isolates were significantly more abundant in the presence of arthropods. Molecular identification revealed identical ITS genotypes of S. lamellicola from both infected pustules and thrips, indicating vector-mediated fungal transmission. While some Simplicillium strains persisted epiphytically without vectors, their spread was minimal. These results highlight a promising approach to enhance the effectiveness of Simplicillium-based biocontrol through natural arthropod-mediated dissemination, warranting field validation of this self-disseminating strategy. Full article

Tomato fruit is susceptible to decay caused by Colletotrichum gloeosporioides. An edible coating derived from essential oils loaded into a chitosan polysaccharide polymer is a sustainable delivery approach to improve coating versatility and stability for reduced reliance on synthetic fungicides to combat anthracnose incidence in tomatoes. The objective of this study was to evaluate the antifungal efficacy of nanostructured thyme essential oil incorporated into chitosan coatings [Nano-(T)-EO-CS] against Colletotrichum gloeosporioides in tomato fruits, and to investigate the underlying mechanisms contributing to its inhibitory effects. Nano-(T)-EO of (1% v/v) showed the greatest antifungal activities while achieving complete inhibition of C. gloeosporioides. At (0.8% w/v) concentration, chitosan inhibited 78% of radial mycelial growth in C. gloeosporioides. Loading Nano-(T)-EO (1% v/v) into chitosan (0.8% w/v) completely inhibited spore germination (100%). The surface electron microscopy revealed that the Nano-(T)-EO-CS coating induced significant deformation and inhibited the growth of C. gloeosporioides. Compared with the control, the Nano-(T)-EO-CS coating reduced disease incidence by 50%, whereas the commercial antifungal agent Sporekill^® reduced incidence by 40% in preventively inoculated tomatoes stored at 10 °C and 85% relative humidity (RH) for 14 days after harvest, and at 18 °C for 3 days at the market shelf condition. Despite chitinase activity peaking on day 14 of cold storage, it peaked significantly on day 7 in Nano-(T)-EO-CS and Sporekill^®-treated tomatoes. The Nano-(T)-EO-CS coating enhanced ferric-reducing antioxidant power and total phenol content in tomatoes for 7 and 14 d of postharvest storage. The chitosan-based edible coating loaded with thyme essential oil offers a sustainable, eco-friendly alternative to chemical fungicides for improving tomato shelf life and reducing decay. Full article

Accurate and timely assessment of crop disease severity is crucial for effective management strategies and ensuring sustainable agricultural production. Traditional visual disease scoring methods are subjective and labor-intensive, highlighting the need for automated, objective alternatives. This study evaluates the effectiveness of a model for field-based identification and quantification of stripe rust severity in wheat using red, green, blue RGB imaging. Based on crop reflectance hyperspectra (CRHS) acquired using a FieldSpec ASD spectroradiometer, two complementary approaches were developed. In the first approach, we estimate single leaf disease severity (LDS) under laboratory conditions, while in the second approach, we assess crop disease severity (CDS) from field-based RGB images. The high accuracy of both methods enabled the development of a predictive model for estimating LDS from CDS, offering a scalable solution for precision disease monitoring in wheat cultivation. The experiment was conducted on four winter wheat plots subjected to varying fungicide treatments to induce different levels of stripe rust severity for model calibration, with treatment regimes ranging from no application to three applications during the growing season. RGB images were acquired in both laboratory conditions (individual leaves) and field conditions (nadir and oblique perspectives), complemented by hyperspectral measurements in the 350–2500 nm range. To achieve automated and objective assessment of disease severity, we developed custom image-processing scripts and applied Random Forest classification and regression models. The models demonstrated high predictive performance, with the combined use of nadir and oblique RGB imagery achieving the highest classification accuracy (97.87%), sensitivity (100%), and specificity (95.83%). Oblique images were more sensitive to early-stage infection, while nadir images offered greater specificity. Spectral feature selection revealed that wavelengths in the visible (e.g., 508–563 nm and 621–703 nm) and red-edge/SWIR regions (around 1556–1767 nm) were particularly informative for disease detection. In classification models, shorter wavelengths from the visible range proved to be more useful, while in regression models, longer wavelengths were more effective. The integration of RGB-based image analysis with the Random Forest algorithm provides a robust, scalable, and cost-effective solution for monitoring stripe rust severity under field conditions. This approach holds significant potential for enhancing precision agriculture strategies by enabling early intervention and optimized fungicide application. Full article

Marine natural products have gained increasing interest in drug research and development because of their unique structures, diverse biological activities, and novel mechanisms of action. Using the antiviral alkaloid aldisine as the lead compound and utilizing the hydrogen bond effects common in drug design, novel derivatives containing an acylhydrazone moiety were designed and synthesized. The structures of these derivatives were systematically analyzed using variable-temperature ¹H-NMR. Antiviral activity tests showed that most derivatives were active against tobacco mosaic virus (TMV), with some compounds outperforming the commercial antiviral drug ribavirin. Notably, 3-methylphenyl- and 3-pyridyl-substituted acylhydrazones 5-6 and 5-12 displayed activity comparable to ningnanmycin, one of the most effective commercial antiviral agents. Molecular docking results indicated that incorporating the acylhydrazone moiety enhances hydrogen bonding between the molecules and target proteins. Additionally, we evaluated the fungicidal and larvicidal activities of these derivatives. Most exhibited significant larvicidal effects against Mythimna separata and Plutella xylostella, along with broad-spectrum fungicidal activity. Four related compounds (5-11, 5-12, 5-13, and 5-17) exhibited high fungicidal activities, and another four compounds (2-4, 5-6, 5-13, and 5-17) exhibited high larvicidal activities. Full article

Pelleting seeds to enhance sowing conditions through the incorporation of pesticides or fertilizers has become a prevalent agricultural practice. This study sought to evaluate the effect of pelletized seeds and the substances they release in the form of an extract on four species of nematophagous fungi. The fungus Pleurotus ostreatus was the most sensitive to the presence of pelletized seeds; the growth of all three evaluated strains of P. ostreatus was inhibited from 42.84 to 94.33% compared to the control. In the case of the fungi Stropharia rugosoannulata and Orbilia oligospora, a statistically significant inhibition of the growth of all three evaluated strains was observed, though this inhibition was less pronounced than in the case of P. ostreatus. In contrast, the inhibitory effect on the fungus Clonostachys rosea exhibited a lower inhibition of mycelial growth (0.65–20.41%) compared to the control. The selection of suitable strains of nematophagous fungi tolerant to substances used for seed pelletization could assist in the management of nematodes. The inoculum of nematophagous fungi can be used in sugar beet sowing as a supplement, but fungi should not be used as part of the seed coatings because their viability is most inhibited in direct contact with fungicides. Full article

Tan spot disease, caused by Pyrenophora tritici-repentis, poses a significant threat to wheat production worldwide. Early detection and precise fungicide application are essential for effective disease management. This study explores the potential of Raman spectroscopy—specifically surface-enhanced Raman spectroscopy (SERS) and coherent anti-Stokes Raman scattering (CARS)—as non-invasive tools for identifying fungal infection and assessing wheat’s biochemical response to propiconazole treatment. The methodology is entirely theoretical; no laboratory experiments were conducted. Instead, all spectral graphs and figures were generated through a collaborative process between the author and Microsoft Copilot, which served as a rendering tool. These AI-assisted visualizations simulate Raman responses based on known molecular interactions and literature data. The results demonstrate the conceptual feasibility of Raman-based diagnostics for precision agriculture, offering a sustainable approach to disease monitoring and fungicide management. Full article

Rice (Oryza sativa L.) is a staple crop for over half of the global population; however, pathogenic infections pose significant threats to its sustainable production. Although chemical pesticides are commonly employed for disease control, their prolonged usage has led to pathogen resistance, reduced effectiveness, and non-target toxicity, rendering them unsustainable for agricultural practices. Nanomaterials (NMs) present a promising alternative due to their small size, tunable release properties, and diverse mechanisms for disease resistance. This review examines how NMs can enhance rice disease management through (1) direct pathogen suppression; (2) the activation of plant defense pathways; (3) the formation of nanoscale barriers on leaves to obstruct pathogens; (4) targeted delivery and controlled release of fungicides; and (5) modulation of the microbiome to bolster resilience. Moreover, we critically analyze the agricultural potential and environmental implications of NMs, develop optimized application strategies, and, for the first time, propose the innovative ‘NMs-Rice-Soil’ Ternary System framework. This groundbreaking approach integrates nanotechnology, plant physiology, and soil ecology. The pioneering framework offers transformative solutions for sustainable crop protection, illustrating how strategically engineered NMs can synergistically enhance rice productivity, grain quality, and global food security through science-based risk management and interdisciplinary innovation. Full article

Postharvest losses in fruits and vegetables, estimated at 20–50% globally, undermine food security and economic stability. Biological control agents (BCAs), including bacteria, yeasts, and fungi, are emerging as eco-friendly alternatives to synthetic fungicides. This review comprehensively analyzes advances in BCAs for postharvest disease control and highlights their mechanisms, impacts on produce quality, and integration into sustainable systems. Additionally, this review delves into the innovative role of nanotechnology-enhanced BCAs (Nano-BCAs), emphasizing nanoencapsulation, improved biofilm formation, targeted delivery, and antimicrobial synergy. While promising, Nano-BCA application requires risk assessment, regulatory clarity, and cost-effective scalability. This synthesis aims to guide future research and application toward sustainable, safe, and efficient postharvest disease management. Full article

Organophosphate pesticides, fungicides, and neonicotinoid insecticides are frequently employed in the cultivation and production of leafy vegetables. The conventional detection methods for these pesticides rely on chromatographic techniques, which are characterized by good precision and sensitivity. Nevertheless, these methods suffer from drawbacks such as complex sample pretreatment, prolonged detection times, and high costs, hindering the realization of on-site detection. This paper introduces a detection method based on surface-enhanced Raman spectroscopy (SERS) for the quantitative and qualitative analysis of pesticide residues in leafy vegetables. Gold nanoparticles (AuNPs) were meticulously synthesized to serve as the substrate for enhancing Raman signals. The average particle size was approximately 50 nm, and a significant absorption peak appeared at 536 nm. The density functional theory (DFT) with the B3LYP/6-311G was utilized to calculate the theoretical Raman spectra of the pesticides. The characteristic Raman peaks of the pesticides were selected as calibration peaks to establish calibration equations relating the concentration of pesticide residues to the intensity of these calibration peaks. By substituting the intensity of the calibration peak corresponding to the lowest detectable limit in the SERS spectra into the calibration equation, the quantitative detection limit was calculated. The study revealed that the detection limit for phosmet residues in Chinese cabbage could be was below 0.5 mg/kg, with an R² of 0.93363, a standard deviation ranging from 3.87% to 8.56%, and recovery rates between 94.67% and 112.89%. For thiabendazole residues in water spinach, the detection limit could be below 1 mg/kg, with an R² of 0.98291, a standard deviation of between 1.71% and 9.29%, and recovery rates ranging from 87.67% to 107.83%. In the case of acetamiprid residues in pakchoi, the detection limit could also be below 1 mg/kg, with an R² of 0.95332, a standard deviation of between 4.00% and 9.10%, and recovery rates ranging from 90.67% to 113.75%. These findings demonstrate that the SERS-based detection method for the semi-quantitative and qualitative analysis of pesticide residues in leafy vegetables is an effective approach, enabling rapid and reliable detection of pesticide residues in leafy vegetables. Full article

Wheat (Triticum aestivum L.) is a crucial global food crop. The intensive crop farming, monoculture cultivation, and impact of climate change affect the susceptibility of wheat cultivars to biotic stresses, mainly caused by soil fungal pathogens, especially those belonging to the genus Fusarium. This situation threatens yield and grain quality through root and crown rot. While conventional chemical fungicides face resistance issues and environmental concerns, biological alternatives like seed priming with natural metabolites are gaining attention. Polyamines, including putrescine, spermidine, and spermine, are attractive priming agents influencing plant development and abiotic stress responses. Spermine in particular shows potential for in vitro antifungal activity against Fusarium. Optimising spermine concentration for seed priming is crucial to maximising protection against Fusarium infection while ensuring robust plant growth. In this research, we explored the potential of the polyamine spermine as a seed treatment to enhance wheat resilience, aiming to identify a sustainable alternative to synthetic fungicides. Our findings revealed that a six-hour seed soak in spermine solutions ranging from 0.5 to 5 mM did not delay germination or seedling growth. In fact, the 5 mM concentration significantly stimulated root weight and length. In complementary in vitro assays, we evaluated the antifungal activity of spermine (0.5–5 mM) against three Fusarium species. The results demonstrated complete inhibition of Fusarium culmorum growth at 5 mM spermine. A less significant effect on Fusarium graminearum and little to no impact on Fusarium oxysporum were found. The performed analysis revealed that the spermine had a fungistatic effect against the pathogen, retarding the mycelium growth of F. culmorum inoculated on the seed surface. A pot experiment with Bulgarian soft wheat cv. Sadovo-1 was carried out to estimate the effect of seed priming with spermine against infection with isolates of pathogenic fungus F. culmorum on plant growth and disease severity. Our results demonstrated that spermine resulted in a reduced distribution of F. culmorum and improved plant performance, as evidenced by the higher fresh weight and height of plants pre-treated with spermine. This research describes the efficacy of spermine seed priming as a novel strategy for managing Fusarium root and crown rot in wheat. Full article

Enhanced colony nutrition can support brood development, resulting in better physiological conditions and increased resilience in adult honey bees, particularly under stress. This study investigated the effects of colony nutrition and adult dietary supplementation with green propolis on bee health under fungicide exposure. Colonies were managed under food restriction or nutritional supplementation for 22 weeks. Newly emerged bees from each colony were then caged and fed protein diets consisting of honey-pollen patties contaminated or not with fungicide, and sucrose sugar syrup with or without aqueous green propolis extract. Bees from supplemented colonies showed greater body weight, higher hemolymph protein levels, and higher consumption of protein food after seven days in cages. Fungicide exposure reduced hemolymph protein levels, altered the expression of detoxification and immune-related genes, and significantly decreased bee survival. Interestingly, propolis supplementation alone changed gene expression patterns and slightly reduced longevity compared to bees not exposed to propolis or fungicide. However, under fungicide stress, bees that ingested propolis survived longer, indicating a protective effect. While colony nutritional supplementation clearly promotes honey bee resilience against fungicide exposure, feeding propolis also showed promising effects, though further studies are needed to determine an optimal dietary concentration. Full article

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using Artemisia absinthium L. extract has gained considerable attention due to its eco-friendly approach and potential applications in food science. This study investigates the synthesis and characterization of Artemisia-mediated ZnO NPs, focusing on their physicochemical properties. The nanoparticles were characterized using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX). Successful synthesis was achieved through a co-precipitation method, resulting in an average particle size of 36.6 nm. The presence of polyphenols and flavonoids in A. absinthium L. extract acted as both a reducing agent and stabilizer for the nanoparticles. The physicochemical characterization revealed strong absorption peaks indicative of ZnO, confirming successful nanoparticle formation. In addition to the structural findings, this study presents novel insights by demonstrating that Artemisia-mediated ZnO NPs possess significantly enhanced antimicrobial activity compared to both pure ZnO NPs and the plant extract alone. The biosynthesized nanoparticles exhibited notably lower minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) values against Staphylococcus aureus, Escherichia coli, and Candida albicans, suggesting a strong synergistic effect between ZnO and the phytochemicals of A. absinthium L. Thus, the study confirms and quantifies the superior antibacterial potential of Artemisia-derived ZnO NPs, offering promising implications for food, biomedical and pharmaceutical applications. Full article