Fungicidal Effect Research Articles

Evaluation of the effectiveness of biological fungicides in various sunflower protection systems

The effectiveness of sunflower protection against septoria was studied in 3 protection systems: chemical, integrated and biologized. Each system had 2 repetitions, in one of them the soil biological fungicide Sternifag, SP (Trichoderma harzianum, strain VKM F-4099D, 1010 CFU/g) was introduced in autumn. The study was conducted in 2021 and 2022 at the Agrobiotechnology field in the Shebekinsky district of the Belgorod region. Biologics were used in integrated and biologized protection systems. In particular, the biological preparation Alirin-B, Zh was used in the biologized protection system. It has been experimentally established that during the autumn application of the soil biological fungicide Sternifag, SP, in all variants of protection systems, an increase in the efficiency of treatments and sunflower yields was noted. It was also found that the studied biological preparations had a growth-stimulating effect on the vegetative organs of plants, including the root system. An economic assessment of 3 sunflower protection systems showed that the average yield over 2 years was higher in all variants when applying Sternifag, SP. The highest yield was obtained with an integrated protection system of 39.3 c/ha. Due to the high costs of drugs, the profitability in the chemical system was in both replications less than other options – 215 and 286%. In the biologized system, profitability was the highest – 536 and 618%, this was due to the cost of biological drugs, which were 2 times less. Thus, it is recommended to introduce integrated and biologized sunflower protection systems, which will contribute not only to reducing the cost of protective measures, but also to reducing the pesticide burden on agroecosystems and improving the quality of finished products through the use of biological pesticides.

Inhibitory effects of berberine on fungal growth, biofilm formation, virulence, and drug resistance as an antifungal drug and adjuvant with prospects for future applications.

Berberine (BBR), an isoquinoline alkaloid found in medicinal plants such as Coptidis rhizoma, Berberis sp., and Hydrastis canadensis, is a distinctive compound known for its dual ability to exhibit broad-spectrum antifungal activity while offering beneficial effects to the host. These attributes make it a highly valuable candidate for antifungal therapy and as an antibiotic adjuvant. This review provides a comprehensive evaluation of BBR's antifungal properties, focusing on its in vitro and in vivo activity, underlying mechanisms, and its influence on fungal pathogenicity, including virulence, biofilm formation, and resistance. Additionally, the antifungal potential of BBR extracts, derivatives, and nanoformulations is examined in detail. BBR demonstrates fungicidal effects through multiple mechanisms. It targets critical fungal components such as mitochondria, cell membranes, and cell walls, while also inhibiting enzymatic activity and transcription processes. Furthermore, it suppresses the expression of virulence factors, effectively diminishing fungal pathogenicity. Beyond its direct antifungal activity, BBR exerts beneficial effects on the host by modulating gut microbiota, thereby bolstering host defenses against fungal infections and reducing potential adverse effects. BBR's interaction with conventional antifungal drugs presents a unique complexity, particularly in the context of resistance mechanisms. When used in combination therapies, conventional antifungal drugs enhance the intracellular accumulation of BBR, thereby amplifying its antifungal potency as the primary active agent. These synergistic effects position BBR as a promising candidate for combination strategies, especially in addressing drug-resistant fungal infections and persistent biofilms. As antifungal resistance and biofilm-associated infections continue to rise, the multifaceted properties of BBR and its advanced formulations highlight their significant therapeutic potential. However, the scarcity of robust in vivo and clinical studies limits a full understanding of its efficacy and safety profile. To bridge this gap, future investigations should prioritize well-designed in vivo and clinical trials to thoroughly evaluate the therapeutic effectiveness and safety of BBR in diverse clinical settings. This approach could pave the way for its broader application in combating fungal infections.

Assessment of inhibitory potentiality of natural compounds against worrisome rice blast fungus

Rice blast, a severe fungal disease, is a substantial threat to global food security, particularly in rice-oriented areas. The Magnaporthe oryzae fungus is increasingly resistant and fast developing in nature. However, chemical fungicides are not only detrimental to the environment but eventually also lose their efficiency. To Tackle this issue, we used an in silico based strategy to identify plant metabolites as bio-fungicides to combat rice blast. Therefore, we screened a total of 56 antifungal natural compounds for the ability to inhibit fungal development through the targeted inhibition of essential proteins in the rice blast pathogen. Molecular docking analysis identified curcumin, myricetin, sterigmatocystin, and versicolorin B as promising candidates with superior binding affinities compared to conventional fungicides like strobilurin, azoxystrobin, and tricyclazole. Notably, myricetin showed the docking score for the SD protein of −233.20, whereas versicolorin B demonstrated the highest binding affinity for the SD protein of −234.23. Among the control fungicides, azoxystrobin displayed the lowest docking score of −177.53. The docked complexes were found to be stable based on molecular dynamics simulations results; the binding free energies of SD-Versicolorin B (−156.018 ± 24.881 kJ/mol) and SD-Myricetin (−137.526 ± 19.977 kJ/mol) complexes were also found to be favorable. Taking everything considered, these naturally occurring substances showed strong fungicidal effects against rice blast causative agent while remaining non-toxic, providing encouraging substitutes for traditional fungicides. In conclusion, these non-toxic natural compounds exhibited strong fungicidal action against rice blast, suggesting promising alternatives to conventional fungicides.

Effectiveness of Chemical Fungicides for the in vitro Control of Fusarium spp. Causing Basal Rot in Onion in Sinaloa, Mexico.

Objective: Identificar la efectividad in vitro de cinco fungicidas químicos, y el porcentaje de inhibición de crecimiento micelial de F. falciforme, F. brachygibbosum y F. oxysporum en la producción de cebolla. Design/methodology/approach: Los aislamientos se sometieron a una prueba de sensibilidad in vitro de cinco fungicidas con concentraciones de 1, 10, 100 y 1000 ppm en medio de cultivo PDA. Se transfirieron discos de 0.5 cm de diámetro de los aislamientos al centro de caja Petri que contenían el medio de cultivo impregnado con los fungicidas. Se estableció un diseño completamente al azar con cinco tratamientos y un testigo, con tres repeticiones por concentración. Se midió el crecimiento micelial y se calculó el porcentaje de inhibición de crecimiento micelial. Results: Se observó diferencia en el porcentaje de inhibición del micelio entre los fungicidas y las especies siendo tubeconazole el más efectivo. Además, se encontró que, a mayor dosis de fungicida, el porcentaje de inhibición micelial disminuye. El fungicida más efectivo para F. falciforme y F. brachygibbosum fue boscalid y verango a bajas concentraciones, y tubeconazole y tiabendazol a altas concentraciones. Para F. oxysporum boscalid y verango fueron más efectivos a bajas concentraciones. Findings/conclusions: En general, F. oxysporum mostró una mayor sensibilidad a todos los fungicidas.

Resveratrol-coated gold nanorods produced by green synthesis with activity against Candida albicans.

Candida albicans is an opportunistic yeast capable of causing a wide range of mucosal, cutaneous, and systemic infections. However, therapeutic strategies are limited to a few antifungal agents. Inorganic nanoparticles have been investigated as carrier systems for antifungals as potential new treatments. In this study, we focused on the antifungal activity of gold nanorods, a specific rod-shaped gold nanoparticle, produced by green synthesis using resveratrol as a metal-reducing agent. The synthesis method resulted in stable control nanoparticles (AuNp) and resveratrol-coated gold nanoparticles (AuNpRSV) with medium sizes of 32.4 × 15.9 nm for AuNp, and 33.5 × 15.3 nm for AuNpRSV. Both AuNp and AuNpRSV inhibited the C. albicans grown at 2.46 µg/mL, exhibited fungicidal effects at 4.92 µg/mL, and significantly decreased filamentation, biofilm viability, reactive oxygen species production and ergosterol levels of C. albicans. In addition, exposure to AuNpRSV reduced the ability of C. albicans to grow in the presence of cell membrane stressors. Transmission electron microscopy revealed enlargement of the cell wall and retraction of the cell membrane after treatment with AuNp and AuNpRSV. Promisingly, in vivo toxicity analysis demonstrated that both nanoparticles maintained the full viability of Galleria mellonella larvae at 49.20 µg/mL. In conclusion, both gold nanoparticles exhibited antifungal activity; however, these effects were enhanced by AuNpRSV. Altogether, AuNps and AuNpRSVs are potential antifungal agents for the treatment of C. albicans infections.

Management of Leaf Blight Disease of Medicinal Plants with Bio-agents and Chemical Fungicides

Leaf blight affecting medicinal plants like Piper longum, Tylophora indica, and Hibiscus subdariffa is a major issue in West Bengal, causing significant damage year-round. Effective management of this disease is crucial. Several chemical fungicides and Trichoderma isolates were evaluated against the disease of these plants under field condition. Carbendazim and mancozeb were found to be effective in Piper longum in terms of higher disease control (47.50 & 41.47%) with lower per cent disease incidence (49.87 & 51.47%) and per cent disease index (25.34 & 28.25%) over the control. Although all the Trichoderma isolates were not effective as chemical fungicides but Trichoderma isolate-3 was found to have more efficiency in disease control (35.23%) compared to other two isolates. Mancozeb was treated as the most effective fungicide in T. indica to control the disease (45.07%) with lower disease incidence (54.87%) and disease severity (27.34%) compared to other treatment and control plot. In contrary in H. subdariffa carbendazim was found the most effective fungicide with lowest disease incidence (47.89%) and disease severity (23.37%) resulting higher disease control (47.81%) compared to control. It was followed by cupper oxychloride and mancozeb comparatively with higher disease incidence (49.79 & 51.43%) and disease severity (25.89 & 31.78%). Whether all the Trichoderma isolates did not show significant efficacy as fungicides but Trichoderma isolate-3 showed comparatively good result in disease control (34.32%) over other two isolates and control plot. So, the aforementioned respective fungicides could be used in the control of leaf blight disease of respective medicinal plant. But to control the disease with bio agents more efficient Trichoderma culture need to be investigated.

Identification of Pseudopestalotiopsis ampullacea as a new pathogen causing tea gray blight in India and its management strategies

Gray blight is a serious threat to the tea [Camellia sinensis (L.) O. Kuntze] production in major tea cultivating countries including India. The disease is caused by Pestalotiopsis-like species. In this study, five isolates of Pseudopestalotiopsis species isolated from symptomatic tea leaf samples in North Bengal, India were investigated. Based on the multi-locus phylogenetic analysis using concatenated sequences of three (ITS, tef-1 alpha, and tub-2) loci, cultural and micromorphological characters, and host association, the fungal isolates were identified as Pseudopestalotiopsis ampullacea F. Liu & L. Cai. The morphological analysis also revealed that the fungal isolates were evidently differentiated from other Pseudopestalotiopsis species. To date, P. ampullacea has not been reported on tea plants in India. Among the five isolates studied, isolate NKT0P03 was randomly selected for pathogenicity tests and its sensitivity to fungicides and microbial antagonists. In pathogenicity test, the isolate showed weak to high virulence reactions on 25 different tea cultivars. The pathogen showed an avirulent reaction on the cultivar TV11. In order to identify an effective management strategy against this new pathogen, synthetic fungicides and microbial biocontrol agents were evaluated in the laboratory. Results revealed that carbendazim + mancozeb, hexaconazole, propiconazole, and valextra were effective fungicides with an 85.1% to 89.8% range of inhibitory activity against P. ampullacea NKT0P03. Among microbial agents, Trichoderma harzianum, T. reesei, T. hamatum, Bacillus subtilis, and Microbacterium barkeri were efficient bioagents against P. ampullacea NKT0P03 with antagonistic activity ranging between 66.6% and 84.2%. Thus, these fungicides and microbial bioagents can be recommended as effective agents for the management of P. ampullacea causing tea gray blight after their field evaluations.

Essential oils as natural sources for the control of Botrytis cinerea: Chemical composition and antifungal effect

The essential oils of cinnamon, clove, bergamot, lemongrass, citronella, rosemary, basil and lemongrass were extracted by hydrodistillation, had their composition determined by gas chromatography coupled with mass spectrometry and were investigated for their potential to restrict Botrytis cinerea cultivar in vitro, a fungus responsible for the gray mold disease that mainly attacks strawberry plants. Their composition was then correlated chemometrically to identify likely compounds that were related to the observed inhibition effects. Five essential oils demonstrated an inhibitory effect on Botrytis cinerea, through the well diffusion method, with the control plate being the plate without the addition of essential oil. Among these, clove, cinnamon and lemongrass showed the greatest action with the lowest inhibitory concentrations (0.85 mg/mL). The best fungicidal effects were for the essential oil of cinnamon (0.85 mg/mL), clove (1.27 mg/mL) and aloysia (2.12 mg/mL). The main correlated compounds were cinnamaldehyde, eugenol, β-citral and citronellal. Through the analysis of the main components, it is observed that lemongrass essential oil is closer to clove essential oil and, subsequently, to aloysia essential oil, having some compounds in common, among them limonene and citral.

Screening of Mango Varieties against Anthracnose Diseases Caused by Colletotrichum gloeosporioides and Its In vitro Management through Biocontrol Agents and Fungicides

Mango (Mangifera indica L.), known as the "King of Fruits," is a major fruit crop cultivated in India and worldwide. Anthracnose, caused by Colletotrichum gloeosporioides, is a primary biotic stress affecting mango production, yield, and export quality in all mango-growing regions. This study evaluated the response of mango varieties to anthracnose and its management using effective fungicides and biocontrol agents. Ten C. gloeosporioides isolates were isolated from samples collected from the Kollam and Thiruvananthapuram districts in Kerala. Among them, isolate C10 from Thiruvananthapuram was the most virulent. Among five local mango varieties (Kottukonam, Priyoor, Neelam, Rumani, and Totapuri) screened through artificial inoculation, Totapuri displayed the lowest disease severity (45.4%), followed by Neelam and Rumani, while Kottukonam exhibited the highest (72.33%). In vitro, the study of different biocontrol agents showed that Bacillus amyloliquefaciens VLY24 showed 37.08% inhibition against the pathogen, followed by 32.87% inhibition by Bacillus velezensis PSCE-10. Carbendazim 50% WP at 0.1% and 0.2% exhibited 100% mycelial growth suppression.

Analysis of the stereoselective fate and toxicity of penflufen in the water-sediment system for risk reduction

Chiral succinate dehydrogenase inhibitor (SDHI) fungicides are widely used in agricultural production, but there is insufficient research on their environmental risk in water–sediment ecosystems. Here, the stereoselective fate and toxic effects of the chiral SDHI fungicide, penflufen, in the water–sediment system were investigated. The results showed that S-penflufen is more persistent in water, sediment, and zebrafish. Additionally, the sorption coefficient (Koc) in sediment and uptake rate constant (Ku) in zebrafish of S-penflufen were higher than those of R-penflufen. The acute toxicity of S-penflufen to zebrafish, Daphnia magna and Chironomus kiiensis were 32-, 6.1-, and 8.9-fold higher than those of R-penflufen. The AlphaFold2 and molecular docking results showed that S-penflufen had stronger binding capability with SDH in the three water–sediment organisms than R-penflufen. Therefore, S-penflufen induced stronger sub-chronic toxic effects on zebrafish than R-penflufen, even at 0.05 mg/L. The results of multi-omics analysis showed that S-penflufen affected the tricarboxylic acid cycle in zebrafish and induced antioxidant, detoxification, and immune system responses, ultimately affecting zebrafish metabolic processes and cellular function. The overall results indicate that S-penflufen has a higher risk in water–sediment systems. Moreover, combining multi-omics and AlphaFold2 techniques facilitates the elucidation of the molecular mechanism of the stereoselective toxic effects of chiral pesticides.

Antifungal Efficacy of Zinc Oxide Nanoparticles against Anthracnose and Southern Blight Disease in Green Gram

Nanotechnology has rapidly advanced in the 21st century, with significant developments in the synthesis and application of nanoparticles. ZnNps (Zinc nanoparticles) were synthesized using extracts from mehandi (Lawsonia inermis), neem (Azadirachta indica), marigold (Tagetus erecta) and ginger (Zingiber officinalis). ZnNps were synthesized after analyzing the compatability of the plant extracts with the test pathogens. This study investigates the antifungal activity of green synthesized zinc nanoparticles (ZnNps) in the laboratory against Colletotrichum lindemuthianum, the causative agent of anthracnose in mung beans and Sclerotium rolfsii causing southern blight in mung bean using the poisoned food technique. Various concentrations (100ppm, 250ppm and 500ppm) of zinc nanoparticles derived from neem, mehandi, marigold and ginger were evaluated alongside corresponding plant extracts and Zinc nitrate hexahydrate at 250ppm. Results indicated significant fungistatic activity, with Mehandi ZnNps at 500ppm exhibiting the highest efficacy, demonstrating minimal mycelial growth (28.00mm) and a growth inhibition rate of 68.88% followed by Marigold and Neem ZnNps against Colletotrichum. As for Sclerotium, Neem ZnNps at 500 ppm exhibiting the highest efficacy, demonstrating minimal mycelial growth (15.00 mm) and a growth inhibition rate of 83.33% followed by ginger and Mehandi. All tested ZnNps concentrations outperformed their respective plant extracts and Zinc nitrate hexahydrate, confirming the potential of green synthesized ZnNps as effective agents. This study provides an eco-friendly alternative to chemical fungicides, addressing the increasing need for sustainable agricultural practices to combat fungal diseases in mung beans. These findings underscore the potential of green synthesized ZnNps as effective ecofriendly fungicides.

Evaluation of Novel Picolinamide Fungicides (QiI) for Controlling Cercospora beticola Sacc. in Sugar Beet

Studies were initiated to find new effective fungicides to use under field conditions to discover novel approaches for optimizing disease management in sugar beet crops. Cercospora leaf spot (CLS), a prevalent foliar disease in sugar beet crops worldwide, is caused by the fungal pathogen Cercospora beticola Sacc. This disease has become the most prevalent pathogen in sugar beet crops across nearly all European growing regions, including Hungary. The epidemic spread of this disease can cause up to 50% yield loss. The use of fungicides has been a cornerstone in managing CLS of sugar beet due to the limited efficacy of non-chemical alternatives. However, the emergence of fungicide-resistant strains of Cercospora beticola Sacc. in recent decades has compromised the effectiveness of certain fungicides, particularly those belonging to the QoI (FRAC Group 11) and DMI (FRAC Group 3) classes. Hungary is among the many countries where resistance to these fungicides has developed due to their frequent application. Picolinamides represent a novel class of fungal respiration inhibitors targeting Complex III within the Quinoine-Inside Inhibitor (QiI) group. Two innovative fungicides from this class, fenpicoxamid and florylpicoxamid (both classified under FRAC Group 21), were evaluated for their efficacy in managing CLS of sugar beet in Hungary during the 2020 and 2021 growing seasons. Both fungicides were applied as formulated products at various application rates and demonstrated superior efficacy in controlling CLS compared to untreated control plots and the reference fungicides difenoconazole and epoxiconazole. The results consistently demonstrated that all tested application rates of fenpicoxamid and florylpicoxamid effectively controlled CLS in sugar beet, exhibiting a clear dose–response relationship. Disease severity, as measured by the area under the disease progress curve (AUDPC), was significantly correlated with yield reduction but showed no significant association with root sugar content. Moreover, data from both study years indicated that picolinamide fungicides applied at a rate of 75 g ai/ha significantly outperformed difenoconazole (100 g ai/ha) in controlling the CLS of sugar beet. Additionally, higher application rates of picolinamides at 100–150 g ai/ha outperformed epoxiconazole at 125 g ai/ha in disease suppression. Fenpicoxamid is currently registered for use in cereals within Europe, and outside of Europe in Banana against Black Sigatoka (eff. Mycosphaerella fijiensis). Florylpicoxamid, while not yet registered in Europe, is undergoing approval processes in various countries worldwide for a range of crops and is continually being evaluated for potential market introduction. Additional details regarding the efficacy of florylpicoxamid against CLS in sugar beet were presented at ‘The 10th International Conference on Agricultural and Biological Sciences (ABS 2024, Győr-Hungary)’ in 2024.

Microbial Diversity and Biodegradation Mechanism of Microorganisms in the Dingtao M2 Tomb.

The Dingtao M2 tomb, the largest and best-preserved imperial "Huangchangticou" tomb in China, holds great significance for its conservation. Currently, varying degrees of microbial degradation are occurring on the surfaces of the M2 tomb. This study aimed to determine the microbial diversity of the M2 tomb and its surrounding environment during July 2021 and August 2022. High-throughput metagenomic sequencing revealed that the dominant fungus on the surface of the tomb chamber was Dacrymyces stillatus (DTT1) in July 2021, which changed to Talaromyces pinophilus (DTT2) in August 2022. Enzymatic activities for cellulose and lignin degradation suggested that DTT1 has high levels of manganese peroxidase, lignin peroxidase, laccase, and cellulase. The wood of the tomb contained higher levels of Fe2+ and Ca2+, and experiments with different concentration gradients of these ions in the culture medium revealed that DTT1 exhibited greater activity of cellulose and lignin degradation in environments with higher concentrations of Fe2+ and Ca2+. DTT2 degraded both cellulose and lignin. Lastly, a laboratory plate inhibition experiment demonstrated that isothiazolinone fungicide had a significant fungicidal effect on these two dominant fungi. This study provides valuable data and a theoretical basis for the preservation of the M2 tomb and other wooden cultural relics.

Fusarium spp. in Metalworking Fluid Systems: Companions Forever.

Water-miscible metalworking fluids (MWFs) are utilized in a variety of metal removal and forming operations. For end-use, formulation concentrates are diluted in water, creating conditions conducive to microbial growth and metabolism, possibly compromising the fluid's integrity and mechanically obstructing filters or piping systems. Metalworking machines offer additional habitats on surfaces that are in permanent or temporary contact with MWFs. For that reason, biocides have been incorporated into concentrates for years, but legal constraints will restrain their use in the future. While bacterial contamination of MWFs is well documented, fungal contamination is often overseen and infrequently reported in the literature. In this study, we report fungal prevalence in in-use MWFs sampled worldwide over 10 years, and we are convinced that the presence of fungi is the norm rather than the exception. In addition, we evaluated the inhibitory effect of fungicides on fungal growth, sporulation and spore viability using traditional culture-dependent methods and flow cytometry. In essence, we show that the effectiveness of these fungicides is limited and dependent on the chemical construction of the fluid. We think that the ecology created by water-diluted MWFs is of higher importance than the anti-fungal activity of single components.

Investigating the Antagonistic Effects of Novel Combination Fungicides against Fusarium oxysporum f. sp. ricini under In-vitro Conditions

Aim: The study aimed to assess the efficacy of nine novel fungicide combinations against Fusarium oxysporum f. sp. ricini, the causal agent of wilt disease in castor. Methodology: The efficacy of fungicides was evaluated using the poisoned food technique under in-vitro conditions. Radial mycelial growth of the pathogen was measured across various concentrations (100 to 1000 ppm) of the fungicide combinations to determine their impact on mycelial inhibition. Results: Results indicated a substantial reduction in radial mycelial growth with increased fungicide concentration. Among the tested fungicides, Tebuconazole + Trifloxystrobin and Prochloraz + Tebuconazole recorded complete mycelial inhibition (100 %) at all the tested concentrations, demonstrating significant fungicidal activity followed by Hexaconazole + Captan with a mean mycelial inhibition of 85.2 %, indicating strong potential for disease management. In contrast, the least mean mycelial inhibition (24.7 %) was observed with Thiophanate methyl + Pyraclostrobin. Conclusion: These findings underscored the importance of selecting effective fungicide combinations to manage F. oxysporum f. sp. ricini, thereby enhancing crop protection and agricultural sustainability.

Optical Properties and Antimicrobial Activity of Si/PVP Hybrid Material Combined with Antibiotics.

Silica-poly (vinylpyrrolidone) hybrid material was prepared using the sol-gel method. Tetramethyl ortosilane (TMOS) was used as a silica precursor. XRD analysis established that the as-prepared material is amorphous. The morphological structure of the final product was determined by the incorporated PVP. The UV-Vis analysis showed that the obtained hybrid exhibited absorption in the ultraviolet range. The antimicrobial activity of the SiO2/15PVP hybrid material was tested on Staphylococcus epidermidis ATCC 14990, Salmonella typhimurium ATCC BAA-2162, Candida albicans, and Saccharomyces cerevisiae in combination with the following antibiotics: Vancomycin for Gram-positive bacteria, Ciprofloxacin for Gram-negative bacteria, and Nystatin for yeast. The results confirmed a concentration-dependent synergistic effect of the antibiotic in combination with the TM15/PVP hybrid particles, especially at their highest concentration of 100 mg/mL on Gram-positive bacteria and for the Gram-negative Salmonella. On Candida albicans ATCC 18804 and Saccharomyces cerevisiae CCY 21-6-3, the effect was synergistic again, and a fungicidal effect was observed at 6.25 and 1.50 mg/mL for the antibiotic concentration and concentrations of hybrid material at 100 mg/mL. The toxicity on Daphnia magna was also tested. The registered prooxidant activity of SiO2/15PVP shows possible applications at very low concentrations. The obtained results demonstrate the possibility of clinical implementations of the newly synthesized hybrid material.

Crop rotation and fungicides impact microbial biomass, diversity and enzyme activities in the wheat rhizosphere

Sustainable crop production systems should promote large and diverse soil microbial communities to enhance biological soil processes rather than depend solely on chemical interventions that include pesticide applications. Crop rotation increases above-ground temporal diversity which, relative to monoculture, usually increases soil microbial diversity. But comparisons between short and long crop rotations that also include pesticide effects are rare. A 5-yr (2013-2017) field study was conducted to investigate crop rotation and fungicide effects on the soil microbiome and activity. There were nine rotations, with or without fungicide applications, that included four 2-yr rotations (wheat preceded by canola, barley, pea, or flax), four 3-yr rotations where barley or canola were added to the 2-yr rotations, and one rotation where canola and wheat were stacked (canola-canola-wheat-wheat). In 2017, soil microbial biomass, composition, diversity and enzyme activities were measured in the rhizosphere of the final wheat crop in each rotation. Fungicides reduced fungal richness (the number of different fungal taxa) in the wheat rhizosphere (e.g., Chao1 indices of 64.0 vs. 79.9) especially in 2-yr rotations, but rotation length/type and the crops that preceded wheat had different effects on different taxa. Two of the three most predominant prokaryotic phyla, Proteobacteriota and Actinobacteriota, responded differently to rotation length: 3-yr rotations enriched the former (27.4% vs. 20.1% relative abundances), but 2-yr rotations enriched the latter (19.9% vs. 28.3% relative abundances). Relative to oilseed crops preceding the sampled wheat, a field pea preceding crop enriched Actinobacteriota (31.7% vs. 24.8% relative abundances) and the most abundant fungal class, Sordariomycetes (39.1% vs. 22.1% relative abundances), in addition to increasing microbial biomass carbon (MBC) and arylsulphatase activity by 33% and 57%, respectively. Correlations of the relative abundances of fungal or prokaryotic genera with β-glucosidase and arylsulphatase activities were similar (both positive or negative), but they were the opposite of correlations with acid phosphomonoesterase, suggesting a close link between C and S cycling. Besides the nutrient cycling implications of these soil microbial characteristics, there is need to study their biological disease control significance.

Antifungal activity of chalcone derivatives containing 1,2,3,4-tetrahydroquinoline and studies on them as potential SDH inhibitors.

A large number of pathogenic fungi have caused serious damage to the global crop yield, and drug resistance is always a topic that cannot be avoided for traditional fungicides. Therefore, finding efficient, green, and low-toxic fungicides is our primary task, which brings opportunities for the development of natural product green pesticides. Twenty chalcone derivatives containing 1,2,3,4-tetrahydroquinoline were designed and synthesized, and the compounds were tested for their fungicidal effects against eight plant pathogenic fungi in vitro. The results demonstrate that the original splicing did not have fungicidal activity, so a piperazine fragment was introduced; the test results revealed that H1-H10 all had good antifungal activity. Among them, H4 showed the highest inhibitory activity against Phytophthora capsici (Pc) with a median effect concentration (EC50) value of 5.2 μg/mL, which was higher than that of the control drugs Azoxystrobin (EC50 = 80.2 μg/mL) and Fluopyram (EC50 = 146.8 μg/mL). After the study, it was demonstrated that H4 mainly acted on the cell membrane against Phytophthora capsici and inhibited the activity of the marker enzyme of mitochondria (SDH) in the fungus. H4 has significant resistance to Phytophthora capsici and also plays a significant role in inhibiting SDH activity, providing a new direction for the development of green pesticides. © 2024 Society of Chemical Industry.

Inhibition of the Growth of Four Phytopathogenic Fungi by Eucalyptus Wood Vinegar

Purpose: The objective of this work aimed to assess the wood vinegar (WV) from the carbonization of Eucalyptus wood in the inhibition in vitro of Fusarium sp., Ganoderma sp., Macrophomina sp., and Sclerotium rolfsii. Method: WV was added to a culture medium and poured onto Petri dishes. After, the fungi were picked up in 1-mm disks and placed in the center of each Petri dish. The experimental design had five treatments, T1, T2, T3, T4, and T5, with crescent concentrations of WV, respectively, 0 (control), 5, 10, 15, and 20 mL L-1. The variables evaluated were fungal growth, mycelial growth rate index, and percentage of mycelial growth inhibition. Results and Discussion: A gradual decrease in the mycelial growth, in the mycelial growth rate index, and an increase in the percentage of mycelial growth inhibition were determined for all assessed fungi in the concentration of 20 mL L-1 of WV. Hence, the conclusion was that eucalyptus WV presented fungi-toxic properties over the assessed fungi and the product can be considered as an alternative for the chemical control of the incidence of these pathogens in crops and forest plantations. Research Implications: The use of natural products with fungi toxic properties is becoming important for the control of pathogens that attack crops and forest plantations due to the harmful effects of the conventional fungicides on living organisms and the environment. The search for efficient alternative products is therefore a goal to be reached in the field of phytopathology. Originality/ Value: The use of natural products with fungitoxic properties has been gaining ground in the control of pathogens affecting agricultural and forestry crops. This intensifies the search for natural products that are efficient in the biocontrol of phytopathologies.

Efficient Preparation of S-Scheme Ag/AgBr/BiOBr Heterojunction Photocatalysts and Implications for Degradation of Carbendazim: Mechanism, Pathway, and Toxicology.

Carbendazim (CBZ), as a highly effective benzimidazole fungicide, has a good control effect on various crops caused by fungi. However, excessive use of CBZ in water, atmosphere, soil, and crops has serious effects. The efficient degradation of CBZ is an effective way to reduce its toxic effect. In this work, the type of S-scheme Ag/AgBr/BiOBr heterojunction photocatalyst was effectively prepared by a simple one-step solvothermal in situ method and first applied to the mineralization and degradation of CBZ. The effects of the molar ratio of AgBr to BiOBr, catalyst dosage, CBZ concentration, pH value of the original solution, and inorganic salt ions on the photocatalytic degradation performance of CBZ were comprehensively studied. The results showed that, under visible light irradiation, 0.9-Ag/AgBr/BiOBr (0.9-AAB) exhibited the best photocatalytic degradation performance (88.9%) against the concentration at 10 mg/L of CBZ in original solutions with pH of 10. However, the degradation effect was also good at pH 7. After 90 min, the degradation efficiency reached 86.0%, corresponding to a TOC removal efficiency of 84.0%. The results indicate that the main active species are 1O2 and •O2- free radicals according to the free radical quenching experiments and electron spin resonance spectra. Combined with the XPS characterization results, the electron transfer mechanism of the S-scheme heterojunction was deeply revealed. Additionally, the degradation pathway of CBZ was proposed through both the intermediate identification and the theoretical calculation derived from the DFT Fukui index. Finally, the toxicity of CBZ and the degradation intermediates were predicted based on the T.E.S.T.