Peanut web blotch, caused by Peyronellaea arachidicola (syn. Didymella arachidicola / Phoma arachidicola), remains one of the most damaging foliar diseases of peanut in China (Chen et al., 2015; Cui et al., 2016). Since its earliest report from Texas in 1972 (Pettit et al., 1986), the pathogen has spread across major peanut-growing provinces in China, including Henan, Liaoning, Shaanxi, and Shandong during the 1980s to 1990s, highlighting its capacity for rapid geographical expansion (Jun-fan et al., 2013).

The characteristic web-like lesions which are initially needle-shaped gray specks that enlarge into tan, net structured areas develop primarily in the epidermis but may progress to deeper necrosis during severe infection. Under conducive conditions, overwintering conidia germinate and invade epidermal cells, forming a reticulate network that ultimately merges into large blighted regions, leading to defoliation and suppression of pod development (Xie et al., 2023). Yield reductions typically range between 10-20%, but losses may exceed 30% during severe disease outbreaks, imposing substantial constraints on peanut productivity (Ru-jun et al., 2015).

Host range assessment demonstrated that 11 out of 32 tested legume species were susceptible (Pettit et al., 1986), and cultivar-level variation exists, with Virginia and Runner types showing relatively greater tolerance compared to Spanish types. Despite its economic significance, genomic insights into P. arachidicola remain limited. The Wb2 strain possesses a ~34.11 Mb genome encoding 37,330 open reading frames (ORFs) enriched in secretory oxidases, peroxidases, and CAZymes implicated in tissue colonization (Zhang et al., 2019). Another strain, YY187, carries a larger genome (47.33 Mb) with a higher G + C content (56.37%), suggesting genomic diversity that may influence virulence and fungicide responses. Because management strategies have been dominated by repeated chemical fungicide applications, concerns over pesticide residues, environmental contamination, resistance emergence, and declining crop quality are intensifying (Culbreath et al., 2021; Luo et al., 2005). Consequently, innovative and sustainable approaches particularly nano-enabled interventions are urgently needed to ensure long-term peanut health and productivity.

Sustaining crop productivity depends heavily on chemical fungicides and host resistance, but fungal pathogens have continuously adapted by evolving virulence against resistance genes (Jiang and Tyler, 2012) and by developing decreases sensitivity to fungicides (Avenot and Michailides, 2010). Fungicide resistance refers to the heritable reduction in pathogen sensitivity to a fungicide enabling growth at concentrations inhibitory to sensitive isolates. While terms such as tolerance or insensitivity are sometimes used, the global Fungicide Resistance Action Committee (FRAC) recommends using resistance, now universally applied across microbial control disciplines.

This evolutionary process has led to global proliferation of resistant populations, driving yield losses and contributing to mycotoxin contamination, thereby threatening food security (Chen et al., 2019). Methyl benzimidazole carbamates (MBCs) fungicides were among the first site-specific classes to encounter widespread resistance within just a few years of deployment (Hawkins and Fraaije, 2016).

In peanut pathology, the long-term and unregulated use of triazoles/ Sterol demethylation inhibitors (DMIs) has placed intense selection pressure on P. arachidicola populations, accelerating the emergence of azole-resistant isolates (Beg et al., 2025). Key resistance mechanisms include mutations in Cyp51, gene amplification, overexpression of the target enzyme, and enhanced drug efflux. Clinical and agricultural experiences further show that widespread azole usage for human and plant pathogens contributes to persistent multi-environment reservoirs of resistance. As a result, azole resistance has now been documented in at least 30 phytopathogenic fungal species across more than 60 countries, underscoring its global scale and critical relevance to crop protection and public health. Current research on optimized derivatives and hybrid azole molecules aims to overcome these complex evolutionary barriers (Teixeira et al., 2022). However, once resistant alleles are established, they are stably inherited and often exhibit cross-resistance within the same mode-of-action group (Yang et al., 2019). DMI resistance is already escalating across several crop systems (Chitolina et al., 2021), signalling similar risks for groundnut production systems.

Azole fungicides, classified as demethylation inhibitors (DMIs), have been the backbone of fungal disease control for decades because of their systemic mobility and broad antifungal efficacy. Their primary target, the sterol 14-α-demethylase Cyp51, catalyses a critical step in converting lanosterol into ergosterol, a lipid essential for membrane rigidity and cellular homeostasis. When this enzyme is inhibited, ergosterol synthesis collapses and the membrane progressively loses integrity, ultimately killing the fungal cell (Brent and Hollomon, 1995).

Although the inhibitory action of DMI fungicides appears mechanistically simple, phytopathogenic fungi have evolved a highly integrated network of genetic, biochemical, and regulatory adaptation that collectively attenuate or circumvent DMI-imposed selection pressure as showed in Figure 1. These adaptive responses include target-site modifications, increased Cyp51 gene dosage, activation of efflux transporters, and stress-induced tolerance pathways, collectively driving the persistence and escalation of azole resistance. Research across several major plant pathogens including Fusarium graminearum, Penicillium digitatum, Venturia effusa, and F. fujikuroi has revealed that azole resistance does not arise from a single evolutionary route but through diverse and often co-occurring mechanisms (de Chaves et al., 2022).

Resistance to DMIs arises through several mechanisms, including point mutations altering Cyp51 structure, expansion of Cyp51 gene copy number, promoter modifications that elevate Cyp51 transcription, and increase activity of ABC transporter-mediated efflux pumps (Table 1). A striking evolutionary dimension to this problem is the variable complexity of the Cyp51 gene family across fungal taxa. While Saccharomyces cerevisiae and mammals possess only one Cyp511gene, majority of filamentous fungi harbor multiple paralogs, sometimes up to four (Celia-Sanchez et al., 2022). F. graminearum, for example, possesses three paralogs (Cyp51A/B/C), each contributing uniquely to DMI tolerance (Wei et al., 2020). The evolutionary rationale behind these paralogs has long been debated, with hypotheses centered on gene duplication followed by divergent specialization under stress. Compelling support for this view comes from Rhynchosporium graminicola, where a large segmental duplication of Cyp51A identified in 125 global isolates has been directly linked to emerging DMI resistance in multiple regions (Stalder et al., 2023). Beyond permanent genomic alterations, fungi also exhibit priming-based resistance, a phenomenon increasingly recognized in both clinical and plant pathogenic systems. Priming occurs when exposure to sublethal environmental stressors enhances on organism’s ability to withstand future challenges (Tagkopoulos et al., 2008). In Aspergillus fumigatus, subinhibitory concentration of tebuconazole, difenoconazole, or epoxiconazole were shown to increase germination and growth during subsequent DMI exposure, revealing a rapid and reversible form of tolerance (Harish et al., 2022). Even more concerning is evidence that sublethal fungicide stress can induce genomic instability, creating a fertile ground for resistance mutations. Such instability documented in several plant pathogens can accelerate the appearance of adaptive variants (Beckerman et al., 2015). In Sclerotinia sclerotiorum, sublethal DMI exposure significantly increased the frequency of INDELs across the genome, offering a mechanistic explanation for the rapid rise of resistance alleles in field populations (Gambhir et al., 2021). Adding further complexity, regulatory networks also modulate the resistance landscape. For instance, the transcription factor FgSR has been shown to bind cis-regulatory elements upstream of Cyp51A and Cyp51B, orchestrating their expression and enhancing the adaptive capacity of F. graminearum under DMI stress (Huang et al., 2019). Taken together, these molecular, evolutionary, and inducible pathways illustrate why azole resistance continues to expand despite decades of stewardship efforts. As agricultural systems remain heavily dependent on DMIs, understanding these mechanisms is critical not only for resistance monitoring but also for designing next-generation, nanotechnology-driven interventions that can mitigate these adaptive advantages and safeguard long-term disease control.

Reducing chemical selection pressure through cultural and agronomic strategies is a foundational approach for delaying resistance development. Strategies such as limiting annual fungicide applications, rotating products with distinct modes of action, minimizing eradicant treatments, and integrating non-chemical interventions like resistant cultivars or biocontrol agents have been widely recommended (Brent and Hollomon, 1998a; Corkley et al., 2022). However, the effectiveness of these measures heavily depends on consistent farmer compliance and long-term adoption, which is often variable. Baseline pathogen sensitivity assays, including multi-concentration or discriminatory dose tests, enable early detection of shifts in susceptibility, exemplified by pydiflumetofen resistance screening in F. graminearum at 5.0 μg/ml (Shao et al., 2021). Yet, such assays are labour-intensive, require laboratory infrastructure, and are impractical for large-scale or real-time monitoring.

Molecular diagnostics, including PCR, PCR-RFLP, allele-specific PCR, and real-time PCR allow rapid detection of known resistance mutations at population level (Kunova et al., 2021). Loop-mediated isothermal ampliflication (LAMP) further supports onsite detection within approximately 45 minute and has been successfully applied to pathogens such as Botrytis cinerea, Podosphaera xanthii, and Cercospora beticola (Shrestha et al., 2020). Despite these advantages, molecular approaches are limited by their reliance on prior knowledge on specific resistance mutations, rendering them ineffective against novel, rare, or polygenic resistance mechanisms. Moreover, they require specialized equipment, trained personnel, and laboratory facilities, which are often inaccessible in many agricultural settings. These methods generally provide only snapshot of pathogen populations, offering limited insight into evolving resistance dynamics or mixed infections in heterogeneous field conditions.

Epigenetic regulation including DNA methylation and histone modifications has emerged as an additional factor influencing fungicide tolerance, virulence, and stress adaptation (Tang et al., 2021). While clinical inhibitors suggest potential for developing epigenetic fungicides that could bypass conventional resistance mechanisms (Heerboth et al., 2014), practical implementation in crop protection remains largely experimental. The lack of standardized detection methods and field-ready tools further limits the application of epigenetic monitoring for routine resistance surveillance.

These constraints underscore the urgent need for more sensitive, rapid, and integrative detection platforms, providing a strong rationale for exploring nanotechnology-enabled solutions in azole resistance surveillance.

Nanoparticles can be synthesized using a wide range of physical, chemical, and biological approaches including laser ablation, emulsification, pyrolysis, encapsulation, and dispersion-precipitation (Astruc, 2008). Continuous technological refinement has accelerated the development of novel synthesis routes, making comprehensive categorization a dynamic and evolving process. In parallel, increasing attentions has been directed toward in vivo biosynthesis routes employing plants and microorganisms as sustainable alternatives to conventional physiochemical methods (Costa Silva et al., 2017).

Among biological systems, fungi represent particularly efficient platforms for nanoparticle biosynthesis due to their superior protein secretion capacity compared with bacteria and actinomycetes, often resulting in higher nanoparticle yields (Sastry et al., 2003). These distinctive dissimilatory properties allow fungi to mediate rapid, cost-effective, and environmentally benign synthesis of metal nanoparticles. Recognizing this emerging field, Mahendra Rai et al. (2009) introduced the term “myconanotechnology” to encompasses research focused on nanoparticles synthesized using fungal systems. Since then, fungal-mediated nanoparticles synthesized has gained prominence as a powerful green alternative to traditional chemical and physical fabrication methods. Fungi exploit their abundant biomass, extracellular enzymes, and secreted metabolites to reduce metal ions and stabilize nascent nanoparticles, while their inherent bioaccumulation capacity and robust enzymatic machinery further enhance synthesis efficiency (Rami et al., 2024). Fungal nanoparticle biosynthesis can proceed through either intracellular or extracellular pathways; however, extracellular synthesis is generally preferred for large-scale applications due to simplified downstream processing, higher product purity, and improved economic feasibility (Guilger et al., 2017). These advantages closely align with the growing global demand for scalable and sustainable green nanotechnologies.

Microscopic fungi, particularly ascomycetes and imperfect fungi are renowned for producing a vast repertoire of bioactive compounds; nearly 6,400 biologically active molecules have been identified to date (Mahmoud, 2025). Leveraging these metabolic pathways, fungal species such as Verticillium sp., Fusarium oxysporum, Penicillium sp., and Aspergillus fumigatus have shown exceptional capability in synthesizing metal and metal sulfide nanoparticles. Compared with bacterial systems, fungi offer several intrinsic advantages, including larger cellular compartments that facilitate substantial metal uptake and a diverse repertoire of extracellular enzymes capable of rapid bioreduction and nanoparticle stabilization. In addition, fungi are easy to culture, highly scalable, and resilient under diverse environmental, collectively supporting their adoption in industrial scale nanomaterial production. These features have led to their recognition as robust and sustainable biological “biofactories” for nanoparticle generation (Eweis et al., 2024).

Despite the greater complexity associated with their eukaryotic organization, particularly in terms of genetic manipulation, recent advances in fungal genomics, transcriptomics, and metabolic engineering are rapidly expanding opportunities to optimize fungal systems for high-efficiency nanomanufacturing. A notable example is the use of Phoma species to catalyse specific biochemical reactions leading to the formation of inorganic nanoparticles, representing a rational and emerging biosynthetic strategy. Extracellular mycosynthesis of silver nanoparticles (AgNPs) by filamentous fungi offers the additional advantage of producing large quantities of nanoparticles in a relatively pure form within short timeframes, while simplifying downstream processing (Gade et al., 2013). In this context, the in vitro antimicrobial activity of AgNPs synthesized using Phoma capsulatum, Phoma putaminum and Phoma citri was evaluated against major fungal and bacterial pathogens, including Aspergillus niger, Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. All three Phoma species produced extracellular, rapid and eco-friendly AgNPs with strong antimicrobial efficacy (Rai et al., 2015). The resulting nanoparticles ranged from 10–80 nm, 5–80 nm, and 5–90 nm, with mean sizes of 31.85 nm, 25.43 nm, and 23.29 nm for P. capsulatum, P. putaminum, and P. citri, respectively. AgNPs from P. citri exhibited the lowest MIC (0.85 µg mL^-¹) against S. choleraesuis, whereas those from P. capsulatum showed the highest MIC (10.62 µg mL^-¹) against S. choleraesuis, P. aeruginosa, and clinical E. coli isolates. Comparable MIC values (10.62 µg mL^-¹) were also observed for P. citri-derived AgNPs against P. aeruginosa and both clinical and standard E. coli strains, confirming broad-spectrum antifungal and antibacterial activity (Rai et al., 2015).

Within the broader framework of agricultural nanotechnology, fungal-derived nanoparticles offer distinct advantages. Nanoparticles synthesized through fungal pathways frequently display superior biocompatibility, enhanced structural and chemical stability within soil-plant environments, and reduced risks to non-target and beneficial organisms. Additionally, the incorporation of fungal metabolites during synthesis often confers enhanced antimicrobial and antifungal potency, creating nanoparticles with intrinsic biological activity. These attributes make myogenic nanoparticles particularly attractive for the development of next-generation nano formulated fungicides, nutrient delivery systems, and plant growth enhancers, aligning strongly with the growing demand for eco-friendly, efficient, and sustainable tools in modern crop production.

Nanocarriers are broadly classified into four main types: ceramic, carbon-based, organic, and inorganic nanoparticles (Table 2). Among these, inorganic nanoparticles consist of both metals and metal oxides, whereas carbon-based nanomaterials include carbon nanotubes, fullerenes, carbon nanofibers, carbon black nanoparticles, and graphene. Additionally, nanocarriers can be categorized according to their structural dimensionality as zero-dimensional, one-dimensional, two-dimensional, or three-dimensional nanostructures (Ijaz et al., 2020). The following subsection summarize the major classes of nanocarriers relevant to fungicide delivery, with emphasis on their structural attributes, mechanisms of action, and applied potential in sustainable crop disease management.

The long-term effectiveness of azole fungicides is increasingly constrained by formulation-related inefficiencies that inadvertently accelerate resistance evolution rather than suppress it. Conventional azole formulations suffer from poor aqueous solubility, rapid photodegradation, and heterogeneous deposition on plant surfaces, leading to fluctuating exposure profiles at pathogen infection sites (Gikas et al., 2022). These limitations are particularly consequential for foliar pathogens such as P. arachidicola, where repeated cycles of infection and incomplete fungicide coverage favour the persistence and enrichment of azole tolerant subpopulations (Bosch et al., 2014; Sun et al., 2024). In this context, nanotechnology is emerging not merely as formulation upgrade but as a paradigm shift in how azole fungicides interact with both the host plant and the pathogen, redefining precision, persistence, and selectivity in disease control strategies (Table 3) (Asmawi et al., 2024).

At the biochemical level, azoles target sterol 14α-demethylase (Cyp51), disrupting ergosterol biosynthesis and compromising fungal membrane integrity, cellular respiration, and growth (Peyton et al., 2015; Spampinato and Leonardi, 2013). While this mode of action remains highly conserved across filamentous fungi, including P. arachidicola, its effectiveness in the field is increasingly undermined by resistance mechanisms such as Cyp51 overexpression, amino acid substitutions within the azole-binding pocket, and activation of multidrug efflux transports. These mechanisms frequently coexist within individual strains, reflecting strong selection pressure under recurrent azole exposure (Cools and Fraaije, 2013; Whaley et al., 2017). Crucially, such selection pressure is often exacerbated by formulation failure rather than intrinsic fungicide weakness, as sublethal and spatially uneven azole concentrations are potent drivers of adaptive evolution.

Nano-assisted delivery directly addresses this vulnerability by fundamentally altering the physiochemical behaviour of azoles at the plant-pathogen interface. Encapsulation of hydrophobic azole molecules within polymeric, lipid-based, or inorganic nanocarriers shields them from premature degradation while dramatically improving aqueous dispersibility and foliar coverage (Monapathi et al., 2021; Singh et al., 2018). This enhanced dispersion ensures more uniform exposure of fungal propagules to inhibitory concentrations, reducing the probability that resistant individuals survive at spray margins or poorly wetted microhabitats. Empirical evidence from multiple crop systems demonstrates that nano-encapsulated azoles achieve superior antifungal efficacy compared with their conventional counterparts, even at reduced application rates, underscoring the central role of delivery precision in fungicide performance (Ahmad et al., 2023; Campos et al., 2015).

Beyond improved deposition, nanocarriers introduce a second critical dimension: temporal control over fungicide availability. Release kinetics can be precisely tuned by modifying carrier composition, particle size, and matrix cross-linking, enabling sustained delivery that maintains fungicidal concentrations over extended periods. Environment-responsive systems further refine this control, as demonstrated by mesoporous silica nanoparticles that modulate fungicide release depending on moisture or pH conditions (Mas et al., 2014; Wanyika, 2013). Similarly, lignin-based nanocarriers allow programmable release of tebuconazole within plant tissues coupling biodegradability with controlled bioavailability (MaChado et al., 2020). Such sustained-release behaviour is particularly advantageous for managing polycyclic diseases like peanut web blotch, where prolonged protection is required to interrupt successive infection events without repeated fungicide applications.

Nanotechnology also reshapes fungicide-plant interactions in ways that extend beyond delivery efficacy. Reduced contact angles and enhanced adhesion achieved through nanosuspensions increase retention on leaf surfaces, minimizing wash-off losses and environmental contamination while improving uptake at infection-prone sites (Xiao et al., 2022). Surface functionalization further enables targeted interactions with plant tissues, enhancing localization without increasing overall fungicide load. Importantly, emerging multifunctional nanocarriers blur the traditional boundary between crop protection and plant nutrition. Metal-organic frameworks (MOFs)-based systems loaded with hexaconazole have demonstrated not only prolonged suppression of Ganoderma boninense but also enhanced seedling growth through gradual nutrient release during carrier degradation, illustrating how nano-enabled fungicides can be integrated into holistic crop health strategies (Farhana et al., 2022).

Despite these advances, the application of azole nano-formulations specifically against P. arachidicola remain conspicuously underexplored. Recent genomic and resistance-risk assessments in P. arachidicola have identified Cyp51 and efflux transporters as key molecular determinants of azole sensitivity, providing a robust framework for evaluating nano-enabled interventions (Sun et al., 2024). However, the absence of pathogen-specific nano-azole studies represents both a limitation and an opportunity. Established nano-formulation platforms such as polymeric and solid lipid nanoparticles, gated mesoporous systems, lignin nanocarriers, and MOFs have already demonstrated efficacy against diverse azole-sensitive and azole-tolerant fungi and can be readily adapted for P. arachidicola with minimal technological barriers (Campos et al., 2015; MaChado et al., 2020; Mas et al., 2014).

A critical consideration moving forward is that nano-enabled enhancement of azole delivery must be accompanied by rigorous resistance surveillance and environmental risk assessment. Sustained low-level exposure, if poorly calibrated, could inadvertently intensify selection pressure on fungal populations, particularly through efflux-mediated tolerance pathways (Parker et al., 2014). Likewise, the ecological fate of certain nanomaterials especially metallic nanoparticles demands careful evaluation to avoid unintended impacts on non-target microbiota and soil health. Prioritizing biodegradable and biogenic carriers, coupled with molecular monitoring of resistance markers, will therefore be essential for translating nano-azole strategies into durable solutions.

Taken together, nano-assisted azole delivery represents a conceptual shift from simply applying fungicides to engineering their spatial and temporal behaviour within agroecosystems. For peanut web blotch management, this shift offers a powerful opportunity to restore azole efficacy against P. arachidicola, slow resistance evolution, and align disease control with broad sustainability goals. The convergence of fungal genomics, advanced materials science, and precision agriculture now sets the stage for next-generation fungicide design where formulation is as critical as the active ingredient itself.

Conventional fungicides, typically applied as bulk chemical sprays, often exhibited poor foliar adhesion, limited tissue penetration, rapid degradation, and require higher doses, thereby increasing environmental contamination and resistance selection pressure (Brent and Hollomon, 1998b; Popp et al., 2013). By contrast, nano-formulated fungicides leverage engineered nanocarriers to enhance leaf retention, trans-cuticular and systemic transport, and controlled release of active ingredients, resulting in greater efficacy at lower application rates (Dávila Costa and Romero, 2025; Kumar et al., 2025; Sudheep et al., 2025). Figure 3 illustrates how these nano-enabled systems outperform conventional formulations by integrating physiochemical functionalities such as enhances stability, high surface area, redox activity, and tunable surface chemistry that enable synergistic antifungal actions, broaden activity spectra, and reduce reliance on single-target chemistries. Collectively, these attributes translate into improved persistence, lower environmental footprints, and superior disease suppression, even against recalcitrant or partially resistant pathogen populations.

Functionalization with chemical groups or biomolecules allows nanomaterials to interact more effectively with fungal cells, as demonstrated with multi-walled carbon nanotubes (MWCNTs) functionalized with OH-, COOH-, and NH₂ groups, which inhibited spore elongation and germination of Fusarium graminearum irrespective of nanotube length. Similarly, PEGylated zinc nanoparticles (ZnNPs) exhibited increased activity against multiple Fusarium species, Macrophomina phaseolina, Rhizocotonia solani, illustrating how surface modifications enhance fungicidal performance (Ammar et al., 2021).

The role of capping agents further underscores the importance of nanoparticle design. AgNPs synthesized via Trichoderma harzianum filtrates were significantly more effective when capped with organic residues such as amino acids and proteins, inhibiting mycelial growth and sclerotia formation, whereas uncapped NPs failed due to instability and aggregation (Guilger et al., 2017).

Polymeric and inorganic nanomaterials expand this versatility. Chitosan-Cu nanoparticles effectively inhibited mycelial growth and spore germination of Alternaria solani and F. oxysporum, while Chitosan-Carrageenan nanocomposites loaded with mancozeb achieved up to 83% inhibition of Alternaria solani at minimal doses (Kumar et al., 2023). Inorganic nanoparticles such as cobalt and nickel ferrite (CoFe₂O₄ and NiFe₂O₄) disrupted growth and sporulation of C. gloeosporioides, F. oxysporum, and Dematophora necatrix, and graphene oxide effectively suppressed Aspergillus oryzae and F. oxysporum in rice (Sawangphruk et al., 2012).

Encapsulation of hydrophobic fungicides within nanoparticles further enhances their stability, bioavailability, and targeted delivery. Chlorothalonil and tebuconazole, when loaded onto surfactant-free nanoparticles, demonstrated higher uptake and resistance against fungal decay in wood. Similarly, chitosan nanoencapsulation of dazomet and hexaconazole improved uptake and disease control in oil palm against Ganoderma boninense, demonstrating the potential of nanaoformulations to optimize both delivery and therapeutic outcomes (Maluin et al., 2019).

Beyond delivery, nanoparticles serve as multifunctional tools for plant protection, combining analytical, antimicrobial, and genetic delivery capabilities. AgNPs exhibit potent activity against Botrytis cinerea, Rhizoctonia solani, Alternaria alternate, and Macrophomina phaseolina, while copper-based nanocomposites (CuO, Cu2O, and Cu + Cu2O) suppress Phytophthora infestans infections. Zinc nanoparticles enhance both bacterial and fungal resistance, and light-activated TiO2/Zn composites offer targeted suppression of bacterial diseases in plants (Paret et al., 2013). Under greenhouse conditions, ZnO and CuO nanoparticles significantly limited late blight progression in potato plants infected with Phytophthora infestans, achieving substantial reductions in disease severity at low application rates (AlHarethi et al., 2024). Taken together, the evidence underscores how nanomaterials transcend the limitations of conventional fungicide technologies by merging precise delivery, improved persistence, and diverse functional roles, ultimately redefining the framework for sustainable crop protection.

Timely detection remains one of the most decisive factors in preventing fungal epidemics, yet traditional diagnostic tools are slow, labour-intensive, and often reactive rather than preventive. Nano-biosensors address this gap by offering rapid, ultrasensitive detection of fungal spores, toxins, and infection-associated biomarkers directly in the field. Leveraging nanoscale optical, electrochemical, and catalytic properties, these systems can signal pathogen presence within minutes, well before symptoms appear (Ray et al., 2023). By integrating nanosensors into precision agriculture frameworks, farmers gain real-time situational awareness, enabling earlier and more targeted interventions that minimize chemical inputs and avert yield-limiting outbreaks. Through advanced nanosensors, fungal pathogens can now be identified rapidly and precisely, leveraging colorimetric or electrical conductivity changes for near real-time diagnostics (Nainnwal, 2025). This capability overcomes the limitations of conventional methods, which are often slow, labour-intensive, and reactive rather than preventive.

Beyond individual plants, nanosensor-enabled monitoring transforms disease management at the ecosystem scale. Continuous surveillance of soil profile and environmental parameters empowers precision interventions, allowing farmers to anticipate pathogen outbreaks and deploy targeted treatments (Singh, 2023). Such proactive strategies not only contain disease spread but also bolster crop resilience and food security. The economic and environmental advantages are equally compelling. Fungal diseases can reduce yields by 20-40%, threatening both agricultural sustainability and profitability (Ajaz et al., 2024). Nanosensors facilitate rapid agricultural detection and minimize dependency on broad-spectrum fungicides, reducing chemical usage, environmental contamination, and potential human health risks (Ajaz et al., 2024; Sundararajan et al., 2024). Together, these technologies establish a new paradigm for high-precision, sustainable disease management, combing early detection with ecological responsibility.

Despite rapid progress in biogenic nanoparticle synthesis, the translation of fungal nanotechnology into field-ready crop protection tools remains constrained by fundamental production and material performance limitations. The agricultural sector demands industrial-scale quantities of highly uniform, bioactive nanomaterials, yet current mycogenic platforms often struggle to deliver consistent particle morphology, monodispersity, and chemical functionalization at economically viable rates. As (Kumar et al., 2023) emphasize, the long-term integration of nanotechnology into plant disease management is inseparable from high-throughput, cost-efficient manufacturing pipelines capable of meeting the volume and quality benchmarks required for commercial fungicide delivery systems.

Beyond manufacturing capacity, the environmental durability of fungal-derived nanomaterials represents a second critical barrier. Nanoparticles deployed in crop fields must withstand an exceptionally dynamic set of abiotic pressures including ultraviolet radiation, temperature oscillations, humidity shifts, phyllosphere hydrodynamics, and soil physiochemical variability. Under such fluctuating conditions, nanoscale systems often experience aggregation, premature release of active ingredients, altered surface chemistry, or loss of functional bioactivity, ultimately compromising field-level performance. Underscores the urgency of developing robust stabilization chemistries, whereas (Mohanty et al., 2024) warn that insufficient stability can undermine the controlled release kinetics essential for maintain sustained antifungal pressure.

These challenges highlight the broader need for next-generation formulation science tailored specifically for agricultural ecosystems. Promising avenues include cross-linked biopolymer matrices that resist environmental degradation, nano-bio hybrid structures that leverage fungal metabolites for enhanced stability, and stimuli-responsive coating engineered to release azoles only under pathogen-inductive cues. Such innovations will be pivotal for ensuring that mycogenic nanoparticles and azole nanocarriers retain their structural and functional integrity from the moment of synthesis through field deployment.

The rapid advancement of nanotechnology research in agriculture has outpaced the development of regulatory systems capable of addressing its unique physiochemical and ecological behaviours. Across jurisdictions, nanomaterials are largely governed through adaptations of existing chemical, pharmaceutical, and food safety legislation rather than dedicated nano-specific frameworks. This has resulted in heterogenous regulatory approaches, varying levels of precaution, and persistent uncertainty for developers and end-users. While some regions emphasize precaution and lifecycle safety, other prioritize regulatory flexibility and innovation, collectively shaping the global governance landscape for fungal nanotechnology and nanofungicides.

A critical frontier for nano-enabled fungicide resistance management lies in examining how biogenic and azole-loaded nanocarriers behave, degrade, and influence ecological health. Nanoparticles introduced into soil or sprayed on foliage undergo continuous physiochemical transitions (aggregation, dissolution, corona formation, and redox reactions) that redefine their mobility and biological interactions. These transformations determine nanoparticle retention, leaching potential, plant uptake pathways, and their influence on microbial guilds that regulate nutrient cycling (Elmeanawy et al., 2022) emphasize that only integrated models bridging nanotechnology, soil biogeochemistry, microbial ecology, and plant physiology can reliably predict such multi-layered interactions across time.

A parallel challenge is persistence and degradation behaviour, which varies widely with carrier composition and environmental context. Surfactant-based systems show contrasting mineralization patterns; lecithin degrading rapidly while synthetic surfactants like polysorbate 80 degrade slowly, raising concerns about long-term soil accumulation (Maluin et al., 2019). Polymeric nanocarriers likewise differ: PLA persists longer than PLGA due to slower hydrolysis (Elsawy et al., 2017), while elevated temperatures or alkaline pH accelerate breakdown (Sharma, 2019). Such variability complicates predictions about environmental residence times and long-term ecological consequences, particularly under repeated application cycles typical of disease management programs.

These scientific uncertainties directly intersect with public perception, which can influence regulatory decision and adoption trajectories. Without transparent, longitudinal data demonstrating safe degradation pathways and low ecotoxicological risk, public acceptance of nano-enabled agricultural interventions may remain limited. Thus, environmental fate studies are central to the ethical and socially responsible deployment of nanotechnology in modern crop protection. Together, these complexities underscore the necessity for comprehensive environmental life-cycle assessments, improved material design for controlled degradation, and open science communication to foster public trust. Advancing these domains will determine whether they can achieve broad, sustainable integration into agricultural disease management.

Although azole-loaded nanoparticles offer a strategic advantage over conventional fungicide formulation especially for mitigating resistance evolution, the stability of these nanosystems remains a key determinant of field performance. Lipid-based nanocarriers, nanoemulsions, and vesicular systems are particularly sensitive to variations in pH, ionic strength, and temperature, all of which are common stressors in real agricultural environments. When these systems destabilize, premature drug release and droplet coalescence undermine targeted delivery, compromising disease control efficacy (Hassanzadeh et al., 2022).

A major pillar of stability engineering lies in precise optimization of the Hydrophilic-Lipophilic Balance (HLB) of excipients. It was demonstrated that excipients with carefully tuned HLB values support more durable emulsions, improved structural cohesion, and controlled azole release profiles (Asmawi et al., 2019). Mixed surfactant systems such as mixtures of Tween 80 and Tween 60 enhance interfacial packing density and molecular interactions, resulting in superior droplet stabilization (Chang and McClements, 2014) further showed that formulations incorporating medium-chain triglycerides or orange oil yield exceptionally stable nanosystems when combined with high-HLB surfactants. Similarly, revealed that tuning the Tween 80: Span 20 ratio to achieve an HLB of 3:1 produced the smallest and most stable nanocarriers, underscoring the centrality of surfactant engineering in advanced azole delivery platforms. These findings collectively demonstrate that excipient selection, interfacial design, and molecular-level tuning are not minor formulation decisions, instead they are strategic levers that define whether azole Nanofungicides can maintain integrity across agricultural environments.