BACKGROUND:Biofumigation is increasingly recognized as an environmentally friendly strategy for controlling soil-borne pathogens. However, its efficacy is highly dependent on environmental conditions, and practical predictive frameworks remain limited. A mechanistic understanding of how environmental factors interact with microbial communities and chemical metabolites is essential for optimizing biofumigation under field conditions. RESULTS:Environmental factors significantly influenced biofumigation efficacy against Fusarium and Phytophthora. Strong interactive effects among temperature, soil moisture, and biofumigant dosage highlighted the necessity of synergistic multi-factor management in practice. Among these, temperature emerged as the dominant regulator (partial η2 = 0.92-0.96), acting as the primary driver that activates the suppressive pathways. Response surface modeling identified that an optimal balance for practical application was achieved at 41-43 °C, 17-19% soil moisture, and a moderate dosage of 4.76 g m-2. Volatile organic compound (VOC) profiling identified dimethyl disulfide as a key bioactive component, while microbial analyses revealed the significant enrichment of disease-suppressing taxa, particularly Paenibacillus. Structural equation modeling robustly explained 90% of the variance in suppression efficacy, revealing dual mechanistic pathways: temperature primarily drove pathogen inhibition via microbial regulation, whereas biofumigant dosage acted mainly through VOC-mediated pathways. Additionally, high soil moisture negatively impacted both chemical accumulation and biological suppression. CONCLUSION:Biofumigation efficacy is governed by a tightly coupled environmental-microbial-chemical framework. Rather than acting in isolation, high temperature, moderate moisture, and an optimized biofumigant dosage synergistically maximize pathogen suppression, providing actionable mechanistic insights and predictive guidelines for optimizing biofumigation in agricultural settings. © 2026 Society of Chemical Industry.

Allyl isothiocyanate (AITC) is effective as a bio-based fumigant in controlling soil-borne diseases; however, the selective pressure it exerts on soil microecology and evolutionary dynamics remains inadequately characterized. This study systematically investigated the remodeling effects of continuous AITC fumigation on soil microbial communities, functional genes, and functional strains by integrating metagenomic analysis and pure culture techniques. Results demonstrate that AITC drives directional selection from “sensitive” to “tolerant” microorganisms. Fungal communities exhibit greater cumulative damage than bacterial communities, with the proportion of significantly suppressed fungi increasing linearly from 9.3% at baseline to 35.7%. At the genus level, sensitive groups were predominantly enriched in pathogen-associated genera, e.g., Pseudomonas and Xanthomonas, whereas tolerant groups, represented by Bacillus and Streptomyces, maintained ecological dominance under continuous stress. Functionally, AITC induced differential evolution of functional gene repertoires. Nitrogen cycle genes (e.g., amoC) exhibited high negative sensitivity, with significant downregulation by 20%, whereas the TCA core module in the carbon cycle exhibited strong robustness. Virulence assays confirmed EC50 values for tolerant beneficial bacteria (Bacillus spp.) (>40 mg·L−1) were significantly higher than those for pathogens (1.3–7.9 mg/L). This study established a microbial “sensitive-tolerant” response framework under AITC stress, revealing the core potential of endogenous tolerant strains for the precise ecological restoration of fumigated soils.

Chemical fumigants such as dazomet (DZ) and dimethyl disulfide (DMDS) effectively suppress soil-borne pathogens but there is uncertainty regarding the restoration of soil ecological functions in continuous cropping obstacles after fumigation, such as microbe-mediated organic carbon cycling. However, the mechanism by which microbial remediation measures enhance carbon mineralization activity after soil fumigation remains unclear. In this study, we conducted microcosm experiments to investigate the impacts of Bacillus velezensis inoculation on exogenous organic carbon (EOC) mineralization and bacterial community composition and interactions following chemical fumigation. Relative to fumigation alone, B. velezensis addition increased cumulative EOC mineralization by 27% in DZ-treated soils and by 22% in DMDS- treated soils. This enhancement was associated with the enrichment of core taxa and keystone species, which collectively increased microbial activity. Structural equation modeling further confirmed that core taxa (OTU56, belonging to Bacillus) induced positive interactions with indigenous species, which drove the observed enhancement in EOC mineralization. We conclude that B. velezensis facilitates the rapid recovery of soil carbon mineralization after fumigation by selectively reshaping the bacterial community and strengthening bacterial cooperative networks. This work provides a mechanistic framework for microbially driven ecological restoration of fumigant-impacted continuous-cropping obstacle soils and informs the development of sustainable soil-management practices in chemically challenged agroecosystems.

Soil fumigation has been widely reported to increase the bioavailability of manganese (Mn) in soils, yet the microbial processes underlying this response remain poorly understood. Here, we investigated how dimethyl disulfide (DMDS) fumigation regulates soil Mn bioavailability by integrating community-level analysis of Mnoxidizing microorganisms with cellular-level functional characterization of a representative Mn-oxidizing bacterium. 16S rRNA amplicon sequencing with internal spike-in standards for absolute abundance estimation revealed that DMDS fumigation induced significant but transient shifts in the structure and assembly patterns of Mn-oxidizing microbial communities, accompanied by increases in bioavailable Mn. As fumigation effects dissipated, microbial community structure and Mn availability exhibited gradual and partial recovery toward pre-fumigation states, depending on soil type and fumigation intensity. Batch culture experiments with the model Mn-oxidizing bacterium Pseudomonas putida MnB1 further demonstrated that DMDS fumigation resulted in a 44.53-59.38% reduction in Mn oxidation activity and markedly suppressed biofilm formation. These functional impairments were accompanied by large-scale transcriptional reprogramming, with 4639 genes showing differential expression, primarily enriched in energy metabolism and Mn oxidation-related pathways. Protein structure prediction and molecular docking analyses provided complementary molecular-level insights suggesting a potential interaction between DMDS and Mn oxidation-associated proteins. Collectively, these results indicate that enhanced soil Mn bioavailability following fumigation is closely associated with reversible disturbances to microbial Mn oxidation processes across community and cellular scales. This study advances a crossscale functional framework linking fumigation disturbance, microbial Mn oxidation capacity, and redox-sensitive micronutrient dynamics in soil systems.

Soil fumigation is widely used to control soil-borne diseases, yet its effects on nitrification recovery and ammonia-oxidizing microorganisms across contrasting soils remain unclear. This study investigated the impact of dimethyl disulfide (DMDS) fumigation on nitrification dynamics and microbial community assembly in four agricultural soils differing markedly in pH (4.32-6.76) and physicochemical properties. A 15-week incubation experiment was conducted, during which mineral nitrogen dynamics, amoA gene abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and community composition were quantified using kinetic modeling, qPCR, and high-throughput sequencing. DMDS induces transient NH4+-N accumulation, with concentrations increasing to 110-230% of pre-fumigation levels during the first two weeks (P < 0.05), while NO3--N production was significantly suppressed to 20-60% of control levels (P < 0.01). Kinetic analysis shows that DMDS markedly prolongs the time to maximum nitrification rate (t(max)), especially in acidic soils, where t(max) increases from 3.73 to 16.01 weeks under high-dose treatment. Concurrently, the maximum nitrification rate (K-max) declines from 19.08 to 4.02 mg N kg(-1) wk(-1). amoA gene abundance of AOA and AOB is significantly reduced during early recovery (P < 0.05) but returns to near-control levels within 12 weeks, while high-throughput sequencing revealed shifts in the community composition of AOA and AOB, reflected by a decline in Nitrosospira and soil-dependent shifts in Nitrososphaera abundance, accompanied by soil-specific restructuring trajectories and slower compositional recovery in acidic soils. Community assembly processes were defined as stochastic (ecological drift and dispersal limitation) and deterministic (environmental selection driven by soil properties such as pH and nitrogen availability). Overall, stochastic processes dominated at the community level, whereas neutral community model (NCM) analysis revealed time-dependent, taxon-specific deviations from neutral expectations during the early recovery stage, followed by gradual convergence toward neutral dynamics. Soil pH (4.32-6.76) emerged as a key regulator, with nitrification recovery being markedly delayed in acidic soils compared to near-neutral soils. These findings clarify soil-dependent recovery mechanisms of nitrification following DMDS fumigation and provide insight for environmentally informed fumigation management.

Soilborne oomycete diseases, represented by Phytophthora and Pythium, pose a persistent challenge to the management of crops and perennial woody plants owing to the long-term survival and recurrent nature of these pathogens. Conventional target-site fungicides often exhibit inconsistent field efficacy and an elevated risk of resistance development under prolonged use. Fosetyl-aluminum (fosetyl-Al), a systemic fungicide that is rapidly converted to phosphite (Phi), displays a mode of action distinct from that of direct antimicrobial agents. Its disease control efficacy is achieved through two complementary mechanisms. At one level, it shows direct inhibitory activity against oomycetes by limiting spore germination, mycelial growth, and sporulation, in part via disruption of pathogen energy metabolism. More importantly, its primary mode of action involves the induction and amplification of host defense responses, including increased phytoalexin accumulation, enhanced expression of pathogenesis-related (PR) proteins, and strengthened cell wall architecture, ultimately conferring improved resistance to oomycete infection. Accumulating evidence further suggests that fosetyl-Al exerts minimal direct disturbance on soil microbial communities and exhibits good compatibility with arbuscular mycorrhizal fungi and diverse plant growth-promoting rhizobacteria, with its effects on the rhizosphere microecosystem occurring mainly through improvements in host physiological status. Within integrated pest management (IPM) frameworks, fosetyl-Al is therefore more appropriately positioned as a functional agent that supports host health and modulates disease progression, rather than as a rapid curative fungicide, acting synergistically with fast-acting chemicals, biological control agents, and agronomic practices. Based on current research consensus, this review further summarizes existing limitations, and outlines future research priorities and application strategies for fosetyl-aluminum in sustainable agricultural production and forest health management.

Soil fumigation suppresses soil-borne pathogens but also non-target microorganisms, potentially altering soil carbon cycling. However, its impact on soil methane (CH4) metabolism, remains poorly understood. This study investigates the effects of chloropicrin (CP) fumigation on soil carbon dynamics and the microbial mechanisms underlying CH4 emissions. The results unveiled that CP fumigation significantly increased soil dissolved organic carbon by 68.7 %-217.5 %, enhanced CH4 emissions by 9.5 %-165.3 %, and promoted carbon dioxide (CO2) emissions by 14.0 %-60.6 % from days 35-77. CP fumigation directly promoted CH4 emissions through changes in mcrA and pmoA gene abundances, carbon environmental factors, and CO2 concentration. By day 49 post-fumigation, methanotroph abundance and diversity had declined markedly, whereas methanogen abundance increased, indicating greater sensitivity of methanotrophs to CP fumigation. Functionally, CP fumigation severely inhibited CH4 oxidation to formaldehyde (HCHO) and methanol (CH3OH) and suppressed the tetrahydromethanopterin (H4MPT) methanotrophic pathway, while promoting acetate-dependent methanogenesis. Only minor inhibition was observed in the CO2 reduction pathway. Together, these changes stimulated the CH₄ emissions. This study presents the first evidence that soil fumigation substantially alters soil CH4 cycling, revealing its broader ecological consequences.

BACKGROUND:Seed-borne pathogens substantially reduce cucumber yield and seed quality. Seed fumigation may provide effective disinfestation while maintaining seed viability. This study evaluated ethylicin (ETH) as a fumigant for cucumber seeds and compared its performance with that of allyl isothiocyanate (AITC) and chloropicrin (CP). RESULTS:ETH showed the highest overall efficacy in closed-plate bioassays and pot experiments, with over 75% inhibition of the target pathogens, outperforming AITC and CP. ETH fumigation selectively reshaped the seed-associated microbiota, significantly reducing pathogenic fungal and bacterial taxa, including Fusarium (69.55%), Alternaria (52.16%), and Proteobacteria. It also increased germination and emergence by 10.00-24.32%, and improved plant height (7.30-16.60%), stem thickness (2.73-5.11%), and chlorophyll content (6.77-7.80%). ETH-treated plants produced up to seven flowers per plant, compared with three in the control and seed residues ranged from 1.19 to 7.55 mg kg-1. CONCLUSION:ETH shows strong potential as a cucumber seed-fumigant, combining high disease suppression with improved crop establishment. These results offer a practical alternative to conventional fumigants for improving seed health and supporting sustainable cucumber production. © 2026 Society of Chemical Industry.

This study focuses on the severe soil-borne disease problems resulting from the continuous tomato cultivation in China, with the aim of deeply studying the multi-dimensional effects of the combined application of dimethyl disulfide (DMDS) and Trichoderma on soil microecology and tomato yield. Firstly, a plate confrontation experiment was conducted in the laboratory to determine the antibacterial effect of Trichoderma afroharzianum (TAF), and the results indicated that the inhibition rate of TAF against Fusarium oxysporum, an important tomato soil-borne pathogen, was 70.8 %, which suggests TAF could be a potential biocontrol agent. Subsequently, in tomato greenhouses in Fangshan, Beijing, DMDS (60 g/m2) was utilized to fumigate the soil before planting, and then T. afroharzianum (TAF) and Trichoderma harzianum (THZ) were applied for root irrigation of the seedlings during tomato growth. By monitoring the variations in soil microbial communities and resistance to gray mold, it was found that the addition of Trichoderma (TAF and THZ) could effectively inhibit the growth of soil-borne pathogens and significantly reduce the occurrence of gray mold, thereby significantly enhancing tomato yield, with an average increase of 11.5 %. High-throughput sequencing results demonstrated that the addition of Trichoderma suspension after fumigation had a significant impact on bacterial microbial communities, increasing the abundance of beneficial bacteria and fungi such as Truepera, Kernia, Agronomyces, Tumebacillus, and Acidibacter, optimizing the structure of soil microbial communities and promoting the healthy and sustainable development of soil and microecosystems. Moreover, some bacteria exhibit outstanding capabilities in degrading chemical substances in the soil, offering a robust guarantee for restoring the original healthy state of the soil. In conclusion, the research results explicitly demonstrate that the combined application of DMDS and biological agents constitutes a highly effective new approach to overcome soil succession obstacles, providing an innovative control strategy for the precise management of tomato soil-borne diseases.

Fumigants are broad-spectrum pesticides that exhibit multi-site activity and are effective against various pests including fungi, bacteria, insects, nematodes, weeds, and rodents. These chemicals are characterized by small molecular weights, low boiling points, and high vapor pressures. Because of their unique physical and chemical properties, fumigants demonstrate excellent efficacy in pest control through robust diffusion, distribution, and penetration abilities, coupled with specialized fumigation techniques. Although predominantly utilized in soil and grain fumigation, their applications also extend to quarantine and commodity fumigation. This article reviews the mechanisms of action of both traditional and emerging fumigants, such as methyl bromide, chloropicrin, phosphine, allyl isothiocyanate, dimethyl disulfide, sulfuryl fluoride, ethanedinitrile, ethyl formate, and ethylicin. The objective is to provide a theoretical foundation for ongoing research and the development of fumigants and their applications.

BACKGROUND:Soil-borne pathogens severely impact soil health and crop growth. Biofumigation is an eco-friendly method and supports global efforts to reduce chemical fertilizers and pesticides. However, the application in China is limited mainly due to high cost. There is a lack of systematic research on how plant waste biofumigation can improve soil health. We were the first to systematically examine the effects of biofumigation with cabbage and cauliflower wastes on soil and plant factors, and their contributions to crop growth. RESULTS:Results indicated that biofumigation achieved an inhibition rate of soil-borne pathogens between 66.98% and 92.70% at the end of the process, which persisted at 52.89-83.95% during harvest. Additionally, it enhanced soil physicochemical properties, enzyme activity, and the abundance of beneficial microorganisms by 0.41-119.12%. Crop yield also increased by 21.70-77.83%. Comparing the standard cabbage treatment with a higher dosage revealed that the latter did not significantly enhance pathogen inhibition rates but improved yield, suggesting the involvement of alternative mechanisms. A structural equation model revealed that Firmicutes and Bacteroidota increased crop yield by influencing ammonium nitrogen, organic matter, and catalase activity, with ammonium nitrogen being the most significant factor (0.74). CONCLUSION:These findings suggest that biofumigation with Brassica waste provides effective control of soil-borne pathogens at a reduced cost. Additionally, it improves soil fertility and can partially replace chemical fumigants and fertilizers. By minimizing chemical inputs, biofumigation contributes to improved soil health and sustainability. © 2025 Society of Chemical Industry.

Continuous use of substrate cultivation can easily lead to the accumulation of crop pathogens, leading to widespread crop diseases. It is necessary to screen suitable and efficient substrate and space fumigants to keep the healthy development in substrate and greenhouses. This study systematically evaluated the effects of allyl isothiocyanate (AITC) and ethylicin fumigation on pathogens present on the substrate inside greenhouses. The average populations of Fusarium spp. and Phytophthora spp., bacterial and fungal community structures, tomato growth and yield were investigated and analyzed. The results demonstrated that both AITC and ethylicin exhibited significant inhibitory effects on Fusarium spp. and Phytophthora spp. in the substrate, with control efficiencies of 94.2% and 87.5%. Furthermore, these agents achieved 100% inhibition against Fusarium spp. while exceeding 90% Phytophthora spp. in the greenhouse space. Fumigation treatments significantly reduced pathogenic bacteria and increased beneficial microorganisms like Bacillus, Streptomyces and Brevibacillus in the substrate. Additionally, tomato yields increased significantly by over 45%. This study presents the first report on AITC and ethylicin as potential efficient fumigants easily used for both substrate and greenhouse space fumigation, which demonstrates excellent control effect on crop pathogens, with potential application in commercial tomato production in greenhouses to support sustainable agricultural practices.

Plant parasitic nematodes cause substantial economic losses in agricultural products worldwide. Chemical control remains the predominant strategy among available approaches for nematode management. In recent years, a new generation of synthetic nematicides with distinct biochemical targets and improved selectivity has emerged. However, our understanding of the mechanisms of action, activity spectra, and safety of these new agents remains fragmented and lacks systematic integration. Clarifying their modes of action is essential for both the rational development and effective application of these compounds. This article reviews the characteristics and modes of action of both traditional and innovative nematicides, including organophosphates, carbamates, avermectins, cyclobutrifluram, fluazaindolizine, tioxazafen, fluensulfone, and fluopyram, following the classification by the Insecticide and Fungicide Resistance. This review addresses this gap by critically examining modern nematicides currently in use or under development, highlighting their molecular targets, toxicological considerations, and potential roles in sustainable nematode management.

Soil-borne diseases significantly hinder soil health; however, biofumigation presents an environmentally friendly and cost-effective strategy for managing these pests. Currently, research studies on the use of plants as green manures have primarily focused on their benefits for soil quality, whereas overlooking their fumigation effects on soil-borne pests. In this study, we evaluated several soil health indicators for 11 green manures belonging to genus Brassica . Our results indicated that all 11 Brassica species function as the green manure and possess the potential to control pests, with efficacy ranging from 37.55% to 99.19%. Among them, the rapeseed varieties “Zhong Shuang 919” canola and “Hua You Za 9” canola, as well as “Niu Xin No. 3” cabbage, achieved pest control rates of 86.56%–99.19%, increased soil ammonium nitrogen content by 193.73%–252.15%, enhanced organic matter content by 2.68%–13.81%, and boosted the relative abundance of beneficial microbes, such as Bacillus species, by 59.23%–147.85%. During the biofumigation process, isopropyl isothiocyanate was identified as a novel active compound, exhibiting an LC 50 of 1.92 mg/L against Meloidogyne incognita . These findings highlight the fumigation effects of certain Brassica species, suggesting that biofumigation can effectively control soil pests while simultaneously enhancing soil fertility.

With global agricultural practices increasingly focused on sustainability and efficiency, deciphering the complex relationship between soil nutrient turnover and crop nutrient uptake is critical for advancing crop productivity and environmental resilience. This study focuses on the nitrogen transformation process following dazomet soil fumigation and examines how soil microorganisms influence both soil nitrogen cycling and above-ground crop nitrogen metabolism. Fumigation led to significant changes, with ammonium nitrogen increasing by 18.89%-94.82% and nitrate nitrogen decreasing by 30.20%-90.21% in tobacco roots, stems, and leaves. Fumigation also caused a notable shift in the soil microbial community, inhibiting ammonium-oxidizing microorganisms while stimulating denitrifying microbes. These changes not only disrupted the nitrogen balance-reducing soil nitrification by 72.91%-86.51% and increasing denitrification by 197%-324% but also had a cascading effect on above-ground crop nitrogen metabolism. By altering the composition of microbial communities, the process directly influenced soil nutrient turnover, subsequently impacting nutrient availability and distribution in crop. The disruption in nitrogen balance further led to changes in the expression of key nitrogen metabolism enzymes and transporter genes. Specifically, genes related to nitrate and ammonium transporters, as well as amino acid and nitrogen metabolism enzymes, were upregulated. Structural equation modeling confirmed that the shifts in the microbial community were central to driving changes in both soil nutrient turnover and nitrogen distribution in the crop. These findings underscore the critical role of soil microbial communities as a link between soil nutrient cycling and above-ground nutrient metabolism, highlighting their importance in regulating plant nutrient absorption and utilization. This suggests that optimizing microbial management strategies could lead to significant improvements in crop nutrient efficiency.

IntroductionAllyl isothiocyanate (AITC) has demonstrated efficacy as a soil fumigant, effectively controlling soil-borne pathogens and nematodes. Although AITC has a significant effect on soil microbial communities, whether fumigation affects the production of crop endophytes is unclear.MethodsIn this study, AITC was used to fumigate the soil, and the response of endophytic bacteria (in roots, stems, and leaves) in different pepper genotypes (Xiangla359, La Xuan, Shuang Jiao) was investigated.ResultsFumigation with AITC significantly increased soil microbial diversity, stimulated the growth of Actinomycetota, and inhibited Pseudomonadota. However, the effects on endophytic bacteria varied among pepper varieties. Specifically, fumigation significantly reduced microbial diversity in the roots and leaves of Xiangla359, but had no significant effect on La Xuan and Shuang Jiao. Furthermore, the growth-promoting effect of AITC was most pronounced in Xiangla359.ConclusionOur results suggest that while AITC fumigation significantly alters soil microbial diversity and composition, its effects on crop endophytes are genotype-dependent. These findings provide insight into the complex interactions between soil microbial communities and crop endophytes in response to soil fumigation.

Root-knot nematode (RKN) eggs have a multilayered structure that allows them to survive long-term in soil, serving as a major source of reinfestation. Dimethyl disulfide (DMDS), an efficient and environmentally friendly fumigant alternative to methyl bromide, shows significant inhibitory activity against RKN eggs, yet its ovicidal mechanism remains unclear. This study integrated microscopy, multi-omics, and biochemical assays to evaluate DMDS potency under contact and fumigation treatments. RT-qPCR and biochemical assays were used for validation. Results showed that the 24-h EC50 values of DMDS against eggs were 39.88 mg·L-1 for contact treatment and 7.01 mg·L-1 for Petri dish fumigation, while the 4-d EC50 for soil fumigation was 3.91 mg·kg-1. Morphological analyses showed that DMDS treatment caused surface collapse and loss of structural integrity of the eggshell. Transcriptomic and proteomic analysis indicated significant downregulation of chitin synthase and chitin-binding protein genes, consistent with decreased chitinase activity. Furthermore, detoxification pathways, including glutathione metabolism and cytochrome P450-mediated detoxification, were significantly activated. The activities of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione S-transferase (GST), were markedly elevated. In summary, DMDS exerts a multifaceted toxicological effect on nematode eggs: it first penetrates into the egg and induces severe oxidative stress and energy-metabolic imbalance in the embryo, thereby jointly blocking normal embryonic development; this developmental arrest subsequently triggers secondary downstream effects, including disruption of eggshell structure and suppression of chitin biosynthetic processes. These findings provide a theoretical basis for the application of DMDS as a green and efficient fumigant for controlling plant-parasitic nematodes.