Crop Protection Research Articles

Traditional insights into ITK and its delineation for sustainable crop protection

The challenge of producing sufficient food to feed the growing population is aggravated by pests and diseases, with insect pests alone causing 15-20 percent losses in food production. Despite the availability of numerous synthetic and conventional pesticides, traditional practices, known as Indigenous Technical Knowledge (ITK), have been utilized by farmers for generations and have been adequate to date. These practices are deeply rooted in local culture and are environmentally safe. ITKs are a wealth of agricultural wisdom intertwined with religious and cultural beliefs that have significantly contributed to plant protection. It considers the interconnectedness of all living beings and the natural environment. In the context of the current scenario, it is essential to preserve and safeguard these traditional practices. Numerous government centres and policies are dedicated to this goal, recognizing the importance of documenting ITK for future use. Although ITKs were initially practiced without scientific validation, modern research has characterized and supported many of these methods. This review emphasizes the significance of Indigenous Technical Knowledge, the support systems in place and the necessity of detailed documentation and scientific characterization of ITK in use. By focusing on preserving and validating ITKs, we can reduce reliance on harmful chemical pesticides, promote sustainable agricultural practices and ensure food safety and security.

The continuing significance of chiral agrochemicals.

Chemical crop protection is one of the most cost-effective methods for agriculture, as crop failures can be prevented, and sustainable growth can be enabled regardless of the seasons. Agricultural production must be significantly increased in the future to meet the food needs of a growing world population. However, the continued loss of established active ingredients due to consumer perceptions, changing needs of farmers and ever-changing regulatory requirements is higher than annually new active ingredients introduced to the market. The development of innovative active ingredients is therefore essential to continuously improve the selectivity, efficacy and favorable environmental profile of agrochemicals. Molecules with stereogenic centers can be considered here, as they often have different properties than non-chiral molecules. Natural products and their congeners are still a valuable source of inspiration for chiral agrochemicals. However, only a few novel chiral agrochemicals are currently produced on an industrial scale as pure stereoisomers or in enriched form. As of 2018, around 43% of the 35 chiral products introduced to the market (herbicides, fungicides, insecticides, acaricides, and nematicides) contain one or more stereogenic centers in the molecule, and almost 69% of them have been marketed as racemic mixtures of enantiomers or stereoisomers. Surprisingly, the proportion of chiral agrochemicals is in the same order of magnitude as in the time frame from 2007 to 2017 with around 42%, respectively. This report therefore provides an overview of the continued importance of chiral agrochemicals brought to market in the last 6 years and describes the inherent related challenges of modern agrochemicals through the management of key aspects arising from innovative crop protection products. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Deep learning and computer vision in plant disease detection: a comprehensive review of techniques, models, and trends in precision agriculture

Plant diseases cause significant damage to agriculture, leading to substantial yield losses and posing a major threat to food security. Detection, identification, quantification, and diagnosis of plant diseases are crucial parts of precision agriculture and crop protection. Modernizing agriculture and improving production efficiency are significantly affected by using computer vision technology for crop disease diagnosis. This technology is notable for its non-destructive nature, speed, real-time responsiveness, and precision. Deep learning (DL), a recent breakthrough in computer vision, has become a focal point in agricultural plant protection that can minimize the biases of manually selecting disease spot features. This study reviews the techniques and tools used for automatic disease identification, state-of-the-art DL models, and recent trends in DL-based image analysis. The techniques, performance, benefits, drawbacks, underlying frameworks, and reference datasets of more than 278 research articles were analyzed and subsequently highlighted in accordance with the architecture of computer vision and deep learning models. Key findings include the effectiveness of imaging techniques and sensors like RGB, multispectral, and hyperspectral cameras for early disease detection. Researchers also evaluated various DL architectures, such as convolutional neural networks, vision transformers, generative adversarial networks, vision language models, and foundation models. Moreover, the study connects academic research with practical agricultural applications, providing guidance on the suitability of these models for production environments. This comprehensive review offers valuable insights into the current state and future directions of deep learning in plant disease detection, making it a significant resource for researchers, academicians, and practitioners in precision agriculture.

Growth Promotion and Secondary Metabolites of Vegetables by Spraying Soil with Psidium guajava, Aloe vera, Allium sativum and Medicago sativa Extracts at Various Stages of Growth

There is a growing need for sustainable, efficient methods to promote plant growth and protect crops, with plant extracts offering natural, multi-component solutions. Based on previous observations, Psidium guajava, Aloe vera, Allium sativum and Medicago sativa were selected from 17 water extracts to investigate how the application times of soil sprays affect the antioxidant enzymes and secondary metabolites in fruity and leafy vegetables at different growth stages. From 1 week after sowing (WAS) to 4 WAS, all applications increased the shoot fresh weight by 42–69% in cucumbers, 40–64% in tomatoes, 46–65% in kale and 42–63% in lettuce. These applications also increased the photosynthesis, flavonoids and antioxidative enzymes (ascorbate peroxide (APOD) and guaiacol peroxidase (GPOD)), which provided the plants with a balanced supply of nutrients essential for growth. In the real world, these results show that the use of natural extracts (P. guajava and A. sativum) can be a sustainable, eco-friendly alternative to synthetic fertilizers and pesticides, helping to improve crop yields and metabolism without harming the environment. This approach could reduce the reliance on chemical inputs and promote more sustainable agricultural practices, especially in controlled environments, like greenhouses, where crops like cucumbers and kale are grown.

Design and development of pyrazol-5-ylbenzamide derivatives containing chiral oxazoline moiety as fungicides based on molecular docking.

Development of novel chiral antifungal agents for effective control of plant pathogens is urgently needed. In this study, a series of pyrazol-5-yl-benzamide derivatives containing chiral oxazoline moiety were rationally designed and developed based on molecular docking. The in vitro antifungal assay results indicated that compounds (rac)-4h (R1 = Et), (S)-4 h (R1 = S-Et) and (R)-4 h (R1 = R-Et) exhibited remarkable antifungal activities against Valsa mali with median effective concentration (EC50) values of 0.24, 0.06 and 1.08 mg/L, respectively. Preliminary structure-activity relationships (SARs) revealed that the modification of the chiral substituent group at the oxazoline moiety significantly affected the antifungal activities of the target compounds. Furthermore, compounds (S)-4h (87.5%) and (R)-4h (84.3%) exhibited in vivo protective activities comparable to tebuconazole (87.5%) against V. mali. Subsequent molecular docking analysis, succinate dehydrogenase (SDH) enzyme inhibition assays and molecular dynamic (MD) simulations verified that the potential target enzyme of this class of derivatives could be SDH and helped to explain the large difference in antifungal activities of compounds (S)-4h and (R)-4h. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) observations confirmed that these two compounds severely disrupted the mycelial morphology of V. mali. Theoretical calculation studies provided some insight into the subsequent modification of such pyrazol-5-yl-benzamide derivatives. Resistance frequency studies showed that (S)-4h and (R)-4h treatments were less likely to produce resistant fungal strains than tebuconazole. Meanwhile, compounds (S)-4h and (R)-4h exhibited no apparent toxicity to the Apis mellifera L. Therefore, these derivatives are potential candidates for the development of novel chiral fungicides for crop protection. © 2025 Society of Chemical Industry.

Spray-Induced Gene Silencing (SIGS): Nanocarrier-Mediated dsRNA Delivery Improves RNAi Efficiency in the Management of Lettuce Gray Mold Caused by Botrytis cinerea

The plant pathogenic fungus Botrytis cinerea causes significant losses in agricultural production and it is rather difficult to control due to its broad host range and environmental persistence. The management of gray mold disease is still mainly based on the use of chemicals, which could have harmful effects not only due to impacts on the environment and human health, but also because they favor the development of fungicide-resistant strains. In this scenario, the strategy of RNA interference (RNAi) is being widely considered, and Spray-Induced Gene Silencing (SIGS) is gaining interest as a versatile, sustainable, effective, and environmentally friendly alternative to the use of chemicals in the protection of crops. The SIGS approach was evaluated to control B. cinerea infection on lettuce plants. In vitro-synthesized dsRNA molecules (BcBmp1-, BcBmp3-, and BcPls1-dsRNAs) were used naked, or complexed to small layered double hydroxide (sLDH) clay nanosheets. Therefore, treatments were applied by pressure spraying whole lettuce plants lately inoculated with B. cinerea. All sprayed dsRNAs proved effective in reducing disease symptoms with a notable reduction compared to controls. The effectiveness of SIGS in reducing disease caused by B. cinerea was high overall and increased significantly with the use of sLDH clay nanosheets. The sLDH clay nanosheet–dsRNA complexes showed better plant protection over time compared to the use of naked dsRNA and this was particularly evident at 27 days post-inoculation. RNAi-based biocontrol could be an excellent alternative to chemical fungicides, and several RNAi-based products are expected to be approved soon, although they will face several challenges before reaching the market.

Efficient Pest Detection Through Advanced Machine Learning Technique

Crop Protection is the key element to achieve food security. Many studies have been conducted over the decades to avoid crop losses during pre- harvest and post-harvest stages. Crop losses due to pest attack and plant disease spread, reduces the agriculture production and possess a direct impact on the economy of a country. Deployment of Artificial Intelligence (AI) based pest control strategies to detect pest species is under research. In this manuscript, deep learning based EfficientNetB7 architecture and transfer learning methodology is used to develop a real-time resource-efficient pest detection system. EfficientNetB7's innovative compound scaling technique has managed to balance efficiency in terms of computations and accuracy to effectively classify pests through images with minimal resources. The proposed system uses appropriate fine-tuning of training parameters and regularization mechanisms such as optimizers, data augmentation, to effectively develop a pest detection system. The trained model is ported on to STM32 microcontroller using CubeAI in STM32CubeIDE.The model is assessed by using a publicly available dataset, and a classification accuracy of 93.5% is achieved. This system not only automates pest detection but also provides a match percentage for the identified pests, thus supporting precision agriculture. Future work includes increasing the dataset and exploring edge AI techniques for decentralized decision-making. This manuscript showcases the transformative potential of EfficientNetB7 in precision agriculture, offering a scalable, cost-effective, and sustainable solution for the detection of pests with relevant broader impacts on agricultural automation practices.

CRISPR/Cas12a-based method coupled with isothermal amplification to identify Alternaria spp. isolated from wheat grain samples

Alternaria fungal species are considered major plant pathogens, infecting various crops and resulting in significant agricultural losses. Additionally, these species can contaminate grain with multiple mycotoxins that are harmful to humans and animals. Efficient pest management relies on timely detection and identification of phytopathogens in plant and grain samples, facilitating prompt selection of a crop protection strategy. Conventional identification tools, such as morphological characterization and identification based on polymerase chain reaction (PCR)-based methods, are time-consuming and laboratory-bound, limiting their implementation for on-site diagnostics essential in the agricultural industry. Isothermal amplification methods, including nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), and recombinase polymerase amplification (RPA), enable nucleic acid amplification at constant temperatures, making them ideal for point-of-care diagnostics without the need for thermal cycling equipment. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 12a (Cas12a)-based identification, coupled with such isothermal amplification methods, represents an emerging nucleic acid-based technology for detecting plant pathogens at high accuracy and sensitivity. This study aimed to develop a CRISPR/Cas12a-based method integrated with RPA amplification for specific detection of Alternaria spp. isolated from wheat grain samples. The developed method targeted the β-tubulin gene was successfully identified Alternaria strains within a 20-min RPA amplification followed by a 30-min CRISPR/Cas12a reaction and visualization of results. Specificity test included pathogenic fungal species commonly hosted wheat grain, such as Fusarium spp. Bipolaris sorokiniana, and Nigrospora oryzae revealed high specificity of the method for Alternaria species. Furthermore, the method exhibited high sensitivity, detecting Alternaria DNA down to 100 copies, validated by real-time fluorescence readout. A fluorescence assay was employed to visualize the results of RPA and CRISPR/Cas12a reaction, demonstrating substantial implementation potential of the method in point-of-care detection of Alternaria spp. In conclusion, we present the CRISPR/Cas12a-based method as a potentially sustainable approach for the rapid, precise, and specific nucleic-acid-based identification of Alternaria species in grain samples.

Optimization of Operational Parameters for Agricultural Drone Spraying in Maize Crops

This research on an agricultural drone sprayer for maize crops aimed to standardize various operational parameters—such as spraying height, discharge rate, and drone forward speed—based on metrics like effective swath width, droplet density, Volume Median Diameter (VMD), Number Median Diameter (NMD), Homogeneity Factor (HF), spray volume consumed, effective field capacity, field efficiency, and spray deposition at two crop stages (stage 1: 60 DAS and stage 2: 70 DAS). Field experiments indicated that droplet density decreased as spraying height, discharge rate, and forward speed increased. The maximum droplet densities were 12.39, 12.91, and 12.80 droplets/cm² at a spraying height of 2 m, a discharge rate of 100%, and a forward speed of 3 m/s, respectively, for crop stage 1. Average VMD and NMD ranged from 234 µm to 263 µm and 139 µm to 148 µm, respectively, across different parameter levels. An HF close to one was achieved, with values of 1.71, 1.59, and 1.70 at a spraying height of 2.5 m, a discharge rate of 80%, and a forward speed of 5 m/s, respectively, for both stages. Spray volume consumption per hectare decreased with increasing spraying height, decreasing discharge rate, and increasing forward speed. The maximum effective field capacity (EFC) was found as 2.84 ha/h with 80% field efficiency (FE) at a spraying height of 3 m, and 3.02 ha/h with a 73.08% FE for crop stage 1 and 2. Based on the study, the optimal operational parameters were standardized as a spraying height of 2.5 m, a discharge rate of 80%, and a forward speed of 5 m/s.The drone sprayer significantly reduced time, covering one hectare in only 0.32 hours compared to 11.62 hours with a battery-operated manual knapsack sprayer. This research provides valuable insights for optimizing agricultural drone spraying parameters, potentially improving the efficiency of drone sprayers in crop protection practices.

Integrated Crop Protection Management

This paper presents the development of an innovative mobile application designed to assist farmers by providing critical information for optimizing agricultural productivity. The app integrates three core functionalities: soil health analysis, monsoon prediction, and a marketplace for buying and selling crops. Soil health analysis uses advanced algorithms to assess soil quality, offering recommendations for improved crop growth. The monsoon prediction feature leverages meteorological data to forecast rainfall patterns, enabling farmers to plan for planting and irrigation more effectively. Additionally, the app’s buy-sell module facilitates direct trade between farmers, enhancing market accessibility and ensuring fair pricing. Through empirical testing and user feedback, the app demonstrated significant potential in improving farm management practices, increasing crop yields, and enhancing financial outcomes for farmers. This research underscores the importance of integrating technology into agriculture, offering a sustainable and data-driven solution to modern farming challenges.

Seed microbiome in crop disease management

Abstract Sustainable agriculture needs innovative approaches because of the increasing demand for food in which the plant microbiome helps in increase crop production and protection which leads to reduce the use of chemical fertilizers. The microbiome comprises a variety of microorganisms that reside in plant parts such as leaves, stems, roots, flowers and seeds. In particular, the seed microbiome, which inhabits the seed surface and internal tissues, offers an opportunity to improve plant health and resilience to biotic and abiotic stresses. They help to tolerate stress and inhibit the pathogens through induced systemic resistance (ISR), production of antimicrobial, volatile compounds and competition for nutrients and space. These beneficial microorganisms within the microbiome are isolated and characterized using culture-dependent and culture-independent methods via modern omics technology called metagenomics. The importance of the seed microbiome in plant defence mechanisms against pathogens and the factors that affect the composition of the microbiome, such as plant genotype, agricultural practices and environmental impact are addressed in detail in this review.

Avermectins and Their Derivatives: Recent Advances in Biosynthesis and Application.

Avermectins (AVMs) and their derivatives are the most effective and widely used nematicides, insecticides, and acaricides against endo- and ectoparasites of plants, animals, and humans. Demand for avermectins and their highly effective derivatives has increased due to their high cost-effectiveness and wide range of applications as medicines and crop protection products. Due to the unique structures of these compounds and for industrial production purposes, numerous efforts and strategies have been dedicated to enhancing the production of avermectins and creating new analogues in recent years. Here, we have systemically reviewed the recent studies on the biosynthesis and application of avermectins and their derivatives, including avermectin metabolism and its related bioregulation in Streptomyces avermitilis, approaches for enhancing the bioproduction of avermectins, the structure and toxicology of avermectin derivatives, and future prospects, with a focus on the recent advances in biosynthesis and significance of the superior avermectin derivatives.

Evaluating the impact of neonicotinoids on aquatic non-target species: A comprehensive review.

Neonicotinoid insecticides (NNIs) are the fastest-growing class in agricultural protection. They target nicotinic acetylcholine receptors (nAChR) in pests, stimulating the nervous system at low doses and causing paralysis and death at higher concentrations. NNIs are used in crop protection, seed treatment, forestry, agriculture, and flea control in domestic cattle. Effective at lower concentrations and offering long-term control, NNIs are favoured for their systemic activity. However, due to their water solubility, mobility, and moderate persistence, NNIs easily contaminate adjacent aquatic environments via runoff, leaching, or spray drift. While less toxic to vertebrates, their widespread use poses threats to aquatic and terrestrial organisms, causing neurotoxicity, nephrotoxicity, cytotoxicity, genotoxicity, immunotoxicity, hepatotoxicity, endocrine disruption, and reproductive malformations. This review synthesizes research to address knowledge gaps on the environmental impact of NNIs and proposes policies to mitigate their harmful effects on aquatic non-target species.

A review of emerging techniques for pyrethroid residue detection in agricultural commodities.

Pyrethroid pesticides are essential for modern agriculture, helping to control pests and protect crops. However, due to growing concerns about their potential impact on human health and the environment, reliable detection methods are essential to ensure food safety. In this literature review, we explore the techniques used over the past decade to detect pyrethroid residues in agricultural products. Until now, various methods have been developed for detecting pyrethroid pesticides, ranging from conventional analytical approaches to innovative approaches. The conventional analytical approaches include gas, liquid, and supercritical fluid chromatography, micellar electrokinetic capillary chromatography, and enzyme-linked immunosorbent assay. Whereas innovative approaches refer to various optical-based and electrochemical-based sensors. For each method, we evaluate its strengths, limitations, and practical applications. Recent innovations are highlighted, focusing on sensitivity, selectivity, and practical applicability. By summarizing the current state of research, this review serves as a valuable resource for researchers and practitioners, providing insights into the evolving technology and strategy for detecting pyrethroid residue.

Encapsulation of thyme essential oil in dendritic mesoporous silica nanoparticles: Enhanced antimycotic properties and ROS-mediated inhibition mechanism.

Dendritic mesoporous silica nanoparticles (DMSNs) have emerged as promising nanocarriers due to their unique three-dimensional structure and tunable pore characteristics. This study investigates the potential of DMSNs to deliver thyme essential oil (TEO) for enhanced antifungal activity against Fusarium oxysporum (F. oxysporum), a major plant pathogen. DMSNs were successfully synthesized and characterized, followed by the encapsulation of TEO within their porous structure. The resulting TEO@DMSNs composites exhibited significant antifungal activity against F. oxysporum, with inhibition rates reaching 70%, indicating an effective crop protection with a dose-dependent effect. The enhanced antifungal efficacy of TEO@DMSNs compared to free TEO is attributed to the sustained release of TEO and the synergistic effect of the nanocarrier itself. In-depth mechanism investigations revealed that TEO@DMSNs likely disrupted the fungal cell membrane, leading to leakage of cellular contents and ultimately cell death. Moreover, DMSNs and TEO@DMSNs were found to be safe for plant growth, demonstrating their potential as environmentally friendly antifungal agents. This study provides valuable insights into the design and development of advanced nanocarriers for targeted drug delivery and disease management in agriculture.

Influence of sulfur and selenium application on wheat growth in arsenic-contaminated soil.

Wheat could become poisoned when grown in soil with high arsenic (As) content. It is worthwhile to investigate the potential use of sulfur (S) and selenium (Se) for crop protection while detoxifying heavy metal(loid)s. In this study, a pot experiment was conducted under both single and combined application of the two elements. Their effects on wheat growth were analyzed based on As distribution in subcellular tissues and the variation in physiological and biochemical indicators. Despite wheat absorbing and enriching As under S and Se application, its growth status improved. Cell wall and vacuole sequestered majority of elevated As. Phytochelatins (PCs) content increased significantly in the roots, particularly when Se was applied alone. They could chelate with As using thiol groups. Superoxide dismutase (SOD) activity was found to be considerably lower in leaves and without any discernible increase in roots. Peroxidase (POD) activity in roots/stems and/or catalase (CAT) activity in stems increased, and exerted antioxidant effects. The leaf was well protected, and its chlorophyll content significantly increased. The application of S alone had a relatively weaker effect on reducing As content in grains, but the mixed application of Se could induce an inhibitory effect.

Status and measures of food insecurity in Karnali province of Nepal

Food insecurity has been prevailing in the province for more than decades. Province lacks complete study on measures of food insecurity. So, an experiment and discussion with self-observation were conducted throughout the years to determine status and measures of food insecurity in Karnali, Nepal. The research was conducted in Jumla, Mugu & Surkhet of Karnali province with Split-plot design including two or three (as per technical requirement) mini plots to compare intensified or non-intensified cropping/inputs, conservational farming vs. non-conservational farming (three mini plots), artificial pollination vs natural pollination, and crop field protected with insect net vs. without net (part of plant protection), as part of experiment and field trials. Observation and self-study from various projects were carried out to determine status or opportunities of modern farming, drought resilient agriculture, value addition, and promotion of cereals/pseudo-cereals. KII (Key Informant Interview) and FGD (Focus-Group Discussion) conducted with farmer groups (Number:25) and government officials to determine the situation of food security and programs or policy influencing opportunities in the province. Application of innovative tools, technologies and skills through crop or rice intensification, conservational farming, breeding or genetic make-up, crop protection from insect/pest, opportunities of value addition centers, modern farming, and drought resilient agriculture with promotion of cereals or pseudo-cereals and policy influencing or advocacy opportunities have found most effective and sustainable methods of crop improvement for the potential measures of food insecurity in the province. Therefore, the study would support researchers to understand the contextual implications of food security in the province.

Effect of water stress on vegetative growth and leaf concentration of flavonoids in mint (mentha x piperita) under protected cultivation conditions

Medicinal plants, such as mint, contain active ingredients, which, although they are responsible for the therapeutic properties attributed to them, are also responsible for poisoning and adverse reactions that can occur if they are used in inadequate doses, high doses, or for prolonged periods. Many of these plant species have survived for millions of years thanks to their ability to produce substances that protect them from predators or extreme conditions. Even though some of these compounds (condensed tannins, phenols, alkaloids, oligosaccharides, and saponins) can produce a violent and immediate reaction, in most cases, they have a subtle effect that manifests itself with prolonged ingestion. By applying computational chemistry, the structures of bioactive molecules were revealed, representing them three-dimensionally after virtual screening. Therefore, in the project's development, the effect of water stress on the production of flavonoids in the protected mint crop was studied, using the previously measured field capacity and ultimately controlling the irrigation. This was divided into four irrigation application treatments (each 3, 6, 9, and 12 days), evaluating different agronomic variables and through a foliar analysis of the content of flavonoids present in the four treatments under study. The findings of this study, with their significant implications for medicinal plant cultivation, underscore how water stress can affect the production of flavonoids in mint. This knowledge can be directly applied to optimize cultivation practices and enhance the quality of medicinal plants, thereby benefiting the agricultural and pharmaceutical industries.

The effect of crop rotation on populations of major entomophages (review)

The analysis of the literature data on the assessment of the impact of crop rotations on the protection of cereals and other crops from a complex of dominant pests using elements of landscape design is carried out. The conservation of biodiversity and the activation of natural entomophages with an increase in their efficiency contributes to the stabilization of agroecosystems. There has been established a positive effect on the life expectancy and number of natural enemies of phytophages when using nectar crops and other methods, which make it possible to reduce chemical pesticide treatments up to their complete abolition without loss of productivity and product quality. There has been clarified the importance of crop rotations in creating a refuge for natural entomophages. Proper planning of crop rotations refers to methods of manipulating the habitat and can significantly increase the efficiency of entomophages in pest control, which is especially important for organic farming. Scientifically substantiated crop rotation with the inclusion of various methods (sowing of variety mixtures, nectar-bearing crops, marginal trapping crops, etc.) contributes to the stabilization of the ecological state of agroecosystems, increases the level of profitability of agricultural production and safety of the natural environment. The current paper may be of greatest interest to farmers and large commodity producers.

The Synergy of Chitosan and Azoxystrobin Against Fusarium graminearum Is Modulated by Selected ABC Transporters.

The development of innovative and effective strategies to combat fungal pathogens is critical to sustainable crop protection. Fungicides have been used for over two centuries, with traditional copper- and sulfur-based formulations still in use due to their broad-spectrum, multisite mode of action, which minimizes the risk of pathogen resistance. In contrast, modern systemic fungicides, though potent, often target a single site of action, leading to the accelerated emergence of resistant fungal strains. This study explores synergistic interactions between chitosan (CS) and selected fungicides, focusing on their antifungal activity against Fusarium graminearum. Among the fungicides tested, azoxystrobin (Amistar) exhibited the highest 44.88 synergy score when combined with CS (30 kDa, degree of deacetylation ≥ 90), resulting in significantly improved antifungal efficacy. Furthermore, the combination of CS and Amistar with double-stranded RNA (dsRNA) targeting selected ABC transporter genes further amplified antifungal activity by silencing genes critical for fungal tolerance to treatment. This dual synergy highlights the potential of RNA interference (RNAi) as both a functional tool to investigate fungal physiology and an effective antifungal strategy. These findings reveal a promising and environmentally friendly approach to mitigate resistance while improving fungal control. Furthermore, the remarkable synergy between azoxystrobin and CS presents a novel mechanism with significant potential for sustainable agricultural applications, which warrants further investigation to elucidate its molecular basis.