Systemic Fungicides Research Articles

Effectiveness of systemic fungicides against tomato early blight (Alternaria alternata)

Tomato (Lycopersicon esculentum Mill.) is one of the most remunerative and widely grown vegetables in the world. This crop is affected by major fungal pathogens (viz., early blight, late blight, wilt, collar rot, damping off and powdery mildew), among them early blight (Alternaria alternata) is considered as most important one. Among the fungicide tested, the majority were found effective in inhibiting the radial growth of test fungus and highest inhibition was observed in propiconazole 25 EC at 250 and 500 ppm concentration; difenoconazole 25 EC and tebuconazole 25.9 EC at 500 ppm concentration which were equally effective and completely inhibited the mycelial growth and proved significantly superior over rest of the treatments.

Effects of tillage intensity and pesticide treated seeds on epigeal arthropod communities and weed seed predation in a maize-soybean rotation

Tillage practices and the use of pesticide seed treatments (PST) both have the potential to influence epigeal arthropod communities and the ecosystem services they provide, yet few studies have examined both factors in conjunction. A three-year field study (2017–2019) was conducted to assess the independent and interactive effects of tillage and pesticide seed treatments on epigeal arthropod communities and weed seed predation in a long-term row crop tillage intensity experiment located in southeastern New Hampshire, USA. Throughout the study, maize and soybean were planted in rotation with and without pesticide seed treatments (seed coatings containing a mixture of systemic and contact fungicides and neonicotinoid insecticides) under three tillage systems (full-, strip-, and no-till) in a randomized complete block design with four replications. Epigeal arthropod communities were sampled with pitfall traps from September to October 2018–2019 and weed seed predation was assessed over the same period each year from 2017–2019. A total of 1669 individual arthropods, representing 47 taxonomic groups, were observed over the course of the study. In 2018, epigeal arthropod communities differed based only on pesticide seed treatment. The opposite response was observed in 2019, as epigeal arthropod communities differed based only on tillage. Activity densities of Pterostichus melanarius (Illiger) were higher in the strip-till compared to full-till treatment in 2018. Annual levels of post-dispersal weed seed predation by invertebrates (% total seeds removed) varied based on tillage treatment in 2017 and 2019, but not in 2018, and ranged from as low as 6.1 % to as much as 27.2 % depending on year and treatment. These data provide evidence that both pesticide seed treatments and tillage systems can influence the communities of epigeal arthropods that inhabit annual row crop agroecosystems relatively late in the growing season, when the majority of pesticide residues have likely dissipated, and that the weed seed predation services provided by members of this community can be strongly negatively impacted by intensive tillage.

Dissipation and Residue of Chloroisobromine Cyanuric Acid in Ginger and Pepper and Its Dietary Intake Risk Assessment.

Chloroisobromine cyanuric acid is a highly effective broad-spectrum systemic fungicide for disease control in agricultural crops. In this study, the degradation, residue levels, and potential dietary risks associated with the chloroisobromine cyanuric acid residues in two widely consumed crops, pepper and ginger, were evaluated through supervised field experiments conducted at 12 sites for pepper and 4 sites for ginger in China in 2021. A QuEChERS-LC-MS/MS method was established for quantifying cyanuric acid (CYA) in both crops. The method achieved a limit of quantification (LOQ) of 0.02 mg kg-1 for ginger and 0.05 mg kg-1 for pepper, with recovery rates ranging from 91% to 96% for ginger and 84% to 89% for pepper and the relative standard deviation of 2.9% to 11.2% for ginger and 2.8%~12.9% for pepper, respectively. The results indicated that CYA had half-lives ranging from 3.1 to 8.2 days in pepper, and the terminal CYA residues at harvest were all lower than 5 mg kg-1, the maximum residue limit established in China. Furthermore, the chronic dietary risk exposure to chloroisobromine cyanuric acid in ginger and pepper, harvested at a pre-harvest interval of three days and at the normal harvesting time after the application of 50% chloroisobromine cyanuric acid soluble powder (SP), was 37.96%, which was much lower than 100%, indicating no significant health risks to the Chinese population. This study provides basic data for establishing the MRLs and serving as a reference for developing the analytical method applicable to CYA residues in different plant matrices.

Exploring the impact of plant genotype and fungicide treatment on endophytic communities in tomato stems.

This study examines how plant genotype can influence the microbiome by comparing six tomato genotypes (Solanum lycopersicum) based on their traditional vs. commercial backgrounds. Using Illumina-based sequencing of the V6-V8 regions of 16S and ITS2 rRNA genes, we analyzed and compared the endophytic bacterial and fungal communities in stems to understand how microbiota can differ and be altered in plant genotypes and the relation to human manipulation. Our results reflect that traditional genotypes harbor significantly more exclusive microbial taxa and a broader phylogenetic background than the commercial ones. Traditional genotypes were significantly richer in Eurotiomycetes and Sordariomycetes fungi, while Lasiosphaeriaceae was more prevalent in commercial genotypes. TH-30 exhibited the highest bacterial abundance, significantly more than commercial genotypes, particularly in Actinomycetia, Bacteroidia, and Gammaproteobacteria. Additionally, traditional genotypes had higher bacterial diversity, notably in orders like Cytophagales, Xanthomonadales, and Burkholderiales. Moreover, we performed an evaluation of the impact of a systemic fungicide (tebuconazole-dichlofluanide) to simulate a common agronomic practice and determined that a single fungicide treatment altered the stem endophytic microbiota. Control plants had a higher prevalence of fungal orders Pleosporales, Helotiales, and Glomerellales, while treated plants were dominated by Sordariomycetes and Laboulbeniomycetes. Fungal community diversity significantly decreased, but no significant impact was observed on bacterial diversity. Our study provides evidence that the background of the tomato variety impacts the fungal and bacterial stem endophytes. Furthermore, these findings suggest the potential benefits of using of traditional genotypes as a source of novel beneficial microbiota that may prove highly valuable in unpredicted challenges and the advancement in sustainable agriculture.

Evaluation of Fungicides against Fusarium pallidoroseum (Cooke) Sacc. causing Wilt of Coriander In vitro

Coriander (Coriandrum sativum L.) is one of the most important spice crop known to affect by various diseases. Among them, coriander wilt causes serious problems and it is also caused by a newly reported causal agent Fusarium pallidoroseum (Cooke) Sacc. Hence, F. pallidoroseum being new pathogen on coriander, a laboratory experiment was conducted to study the efficacy of different non-systemic fungicides at 1000, 1500 and 2000 ppm; systemic fungicides at 100, 250 and 500 ppm and ready-mix fungicides at 500, 750 and 1000 ppm concentrations against F. pallidoroseum using Poisoned Food Technique. The results revealed that, among non-systemic fungicides, copper oxychloride 50 WP at all concentration found significantly superior with cent per cent mycelial growth inhibition. In contrast, propineb 70 WP found least effective at 1000 ppm concentration (2.71%). Among systemic fungicides, flusilazole 40 EC and thiophanate methyl 70 WP each at 500 ppm concentration gave cent per cent mycelial growth inhibition of F. pallidoroseum. While, kresoxim methyl 44.3 SC found least effective at 100 and 250 ppm concentration (9.74 and 12.95%). Among ready-mix fungicides, prochloraz 5.7 + tebuconazole 1.4 ES at all concentration and azoxystrobin 18.2 + difenoconazole 11.4 SC at 1000 ppm concentration found effective and showed cent per cent mycelial growth inhibition of F. pallidoroseum. While, fluxapyroxad 25 + pyraclostrobin 25 SC at 500 ppm found least effective (18.34%).

Status of Alternaria leaf blight in cotton and its fungicidal management

Surveys were carried out in the three districts of North Gujarat, viz., Aravalli, Sabarkantha, and Banaskantha to investigate the severity of Alternaria leaf blight in cotton, The disease was found to be quite severe and with a mean PDI of 23.77, the Banaskantha district had the highest disease intensity of Alternaria leaf spot disease; in contrast, the average disease intensity in the Aravalli and Sabarkantha districts was 17.94 and 20.44 per cent, respectively. Further, to manage the disease, research was conducted to evaluate the in vitro and in planta bioefficacy of fungicides against Alternaria macrospora of cotton at the Department of Plant Pathology and Alternaria leaf blight in cotton at Agronomy Instructional farm, S D Agricultural University Sardarkrushinagar, Gujarat, respectively. Under in vitro condition, among five systemic fungicides, Carbendazim showed the highest per cent growth inhibition, while Propiconazole showed the lowest. Among different non-systemic fungicides, Mancozeb inhibited the radial growth of A. macrospora the most, while Chlorothalonil inhibited the least. Further, among five combined fungicides, Tebuconazole 50% + Trifloxistrobin 25 WG inhibited the most growth and Captan 70% + Hexaconazole 50 WP inhibited the least. Thereafter, the bio-efficacy of the two most effective fungicides from each group (two systemic, two non-systemic, and two combined fungicides) was tested under field conditions, and the mean disease intensity ranged from 12.28 to 36.43 per cent, with the lowest being Tebuconazole 50% + Trifloxystrobin 25 WG and the highest being untreated control. The highest percentage of illness control (66.29%).. KEYWORDS :Alternaria macrospora, cotton, fungicides

Apple scab: resistance to chemical fungicides

The review highlights the situation with the development of resistance to various systemic fungicides in Venturia inaequalis around the world and in Russia, with an assessment of the prospects for their further use. Information is provided on all fungicides used in Russia against apple scab, their effectiveness at a given time, and a description of each chemical class. Data on the mechanisms of resistance to chemicals in the pathogen, including at the molecular level, are presented. The problem of the development of resistance in V. inaequalis and possible ways of its solution at the present level of scientific knowledge are discussed.

Influence of a New Generation Fungicide on Fusarium Head Blight in Spring Barley

Fusarium head blight is a serious problem in both traditional and intensive agriculture. The way to solve this problem is to use combined systemic fungicides. We therefore studied the effect of the new-generation fungicides Alto Super and KE (Propiconazole 250 g/l and Ciproconazole 80 g/l) combined with the foliar fertilizer Ultramag Super Sulphur-900. Laboratory studies were carried out at the Plant Pathology Laboratory of the People's Friendship University of Russia (RUDN), and field experiments were carried out in 2022 at the experimental field station of the Federal Research Centre "Nemchinovka." Fusarium head blight appeared in late July and early August. The application of the new-generation fungicide Alto Super, KE, alone and in combination with the new foliar fertilizer Ultramag Super Sulphur considerably reduced the development of the epiphytotic fungal disease. Their biological efficacy was 44.53–83.36%. The yield of Nur Spring barley in the experimental variants was higher than in the control variant. The yield gain of spring barley increased by 5.85% for Alto Super, KE, 9.40% for Ultramag Super Sulphur-900, and 12.85% for Alto Super, KE, and Ultramag Super Sulphur-900.

Microbes as carbendazim degraders: opportunity and challenge.

Carbendazim (methyl benzimidazol-2-ylcarbamate, CBZ) is a systemic benzimidazole carbamate fungicide and can be used to control a wide range of fungal diseases caused by Ascomycetes, Basidiomycetes and Deuteromycetes. It is widely used in horticulture, forestry, agriculture, preservation and gardening due to its broad spectrum and leads to its accumulation in soil and water environmental systems, which may eventually pose a potential threat to non-target organisms through the ecological chain. Therefore, the removal of carbendazim residues from the environment is an urgent problem. Currently, a number of physical and chemical treatments are effective in degrading carbendazim. As a green and efficient strategy, microbial technology has the potential to degrade carbendazim into non-toxic and environmentally acceptable metabolites, which in turn can dissipate carbendazim from the contaminated environment. To date, a number of carbendazim-degrading microbes have been isolated and reported, including, but not limited to, Bacillus, Pseudomonas, Rhodococcus, Sphingomonas, and Aeromonas. Notably, the common degradation property shared by all strains was their ability to hydrolyze carbendazim to 2-aminobenzimidazole (2-AB). The complete mineralization of the degradation products is mainly dependent on the cleavage of the imidazole and benzene rings. Additionally, the currently reported genes for carbendazim degradation are MheI and CbmA, which are responsible for breaking the ester and amide bonds, respectively. This paper reviews the toxicity, microbial degradation of carbendazim, and bioremediation techniques for carbendazim-contaminated environments. This not only summarizes and enriches the theoretical basis of microbial degradation of carbendazim, but also provides practical guidance for bioremediation of carbendazim-contaminated residues in the environment.

Exploring the potential of systemic fungicides and plant extracts in suppressing Fusarium wilt of tomato

This comprehensive study has examined the potential of controlling Fusarium oxysporum f. sp. lycopersici causing tomato wilt using systemic fungicides and plant extracts. For the field evaluation of several fungicides, namely Heritage, Pyranil, Folicur, Medallion, Bloom, Benomyl, Defeater, Chipco, Sporta, and Aliette, and plant extracts including Citrullus colocynthis, Eucalyptus globulus, Azadirachta indica, Zingiber officinale, Allium sativum, Nicotiana tabacum, Aloe indica, and Calendula officinalis, tomato seeds were cultivated in the greenhouse at the Vegetable Research Area at Ayub Agriculture Research Institute, Faisalabad, during October 2022. The key findings confirmed the significant effectiveness of fungicides such as Chipco, Bloom, Sporta, and Benomyl. These fungicides, at different concentrations, effectively inhibited the growth of the fungal mycelium. The amount of inhibition ranged from 1.75 cm to 5.84 cm, whereas the control group exhibited an increase of 9 cm. The study highlights the significant inhibitory impact of Bloom on fungal development, resulting in a remarkable reduction of fungal mycelial growth by 85.92%, 81.10%, and 79.90% at various concentrations. In addition, plant extracts demonstrated their natural antifungal characteristics, which varied in efficacy based on the concentrations used. The extracts from A. indica and A. sativum were the most effective, exhibiting the maximum growth inhibition percentage at a concentration of 8%. The present investigation highlighted the potential application of certain fungicides and plant extracts to combat F. oxysporum f. sp. lycopersici. These alternatives provide an environmentally friendly response to synthetic fungicides for managing the disease. Further research is needed to enhance the understanding of the exact efficiency and cost-effectiveness.

Evaluation of non-systemic fungicides for growth inhibition of Alternaria burnsii causing blight in cumin

Cumin (Cuminum cyminum L.) is an important seed spice crop at world level and India is the leading producer (70% of world production), consumer and exporter of cumin in the world. Almost 80% of the crop cultivated is consumed in India. The crop yield is affected by several biotic and abiotic factors, among them, blight caused by Alternaria burnsii (Uppal, Patel and Kamat) is one of the most dreaded diseases and a major production constrain for the successful cultivation of cumin crop. Among the non-systemic fungicides tested, captan 75% WP, chlorothalonil 75 % WP and mancozeb 75 % WP were most effective with 95.67, 95.62 and 94.86 per cent growth inhibition, respectively whereas hexaconazole 5 % EC was most effective in systemic fungicides with 99.98 per cent inhibition followed by Tebuconazole 25.9 % EC 87.40 per cent inhibition.

The investigation of the interaction determination between carbendazim and elastase, using both in vitro and in silico methods

Pesticides, including fungicides, are one of the important groups of environmental toxins that affect human and animal health. Studies have shown that these compounds are considered chemical pollutants. Carbendazim is a systemic fungicide. Unfortunately, excessive use of carbendazim has caused environmental pollution all over the world. In this study, the effect of carbendazim on the enzyme elastase (secreted from the endocrine gland of the pancreas) has been investigated. In a study, the performance and reaction of carbendazim with elastase were investigated using spectroscopic techniques. The stability and structure of elastase enzymes were studied under the influence of carbendazim. The results of fluorescence emission and UV–visible absorption spectrum showed that in the presence of carbendazim, there is an increase in UV–Vis absorption and a decrease in the intensity of the intrinsic fluorescence emission in the protein spectrum. Additionally, a decrease in the thermal stability of elastase was observed in the presence of carbendazim. The stability and structure of elastase enzyme were investigated in the presence of carbendazim. The results revealed that the UV–Vis absorption increased due to the presence of carbendazim, as indicated by the hyperchromic spectrum at 220 and 280 nm peaks. Additionally, the intrinsic fluorescence emission in the protein spectrum decreased with increasing carbendazim concentration at three different temperatures (298, 303, and 313 K). Moreover, the study demonstrated that the TM decreased from 2.59 to 4.58 with the increase of carbendazim, suggesting a decrease in the stability of the elastase structure in response to the elevated carbendazim concentration. According to the results of the research, the interaction between elastase and carbendazim has occurred, and changes have been made in the enzyme under the influence of carbendazim. The formation of the complex between elastase and carbendazim was consistent with the results obtained from molecular simulation and confirmed the thermodynamic data.

Evaluation of Different Fungicides against Fusarium Wilt Pathogen of Bottle Gourd

Bottle gourd (Lagenaria siceraria Mol.Standl.), a prominent member of the cucurbitaceae family, stands as a significant vegetable crop. However, it faces a formidable challenge in the form of Fusarium wilt, attributed to Fusarium oxysporum f. sp. lagenariae, a fungal pathogen. This disease poses a substantial threat to bottle gourd cultivation, affecting its vascular system and leading to symptoms like wilting and yellowing, ultimately endangering the plant's survival. The research was conducted on evaluation of fungicides against F. oxysporum of bottle gourd at department of plant pathology, S. D. Agricultural University during 2018-2020. Four systemic, four non-systemic and four combined fungicides at different concentration were tested against F. oxysporum through poison food technique. Among systemic fungicides, carbendazim found much effective and it recorded the highest growth inhibition (99%) at higher concentration, followed by propiconazole (98%) at 500 ppm. Among non systemic fungicides, propineb recorded the highest growth inhibition (99.50%) at higher concentration, followed by chlorothalonil (73.83%) at 2000 ppm. Among combined fungicides, carboxin + thiram recorded the highest growth inhibition (99.50%) at higher growth inhibition at 1000 ppm.

In vitro Evaluation of Fungicides against Anthracnose of Betelvine (Piper betle L.)

Background: Betelvine is important commercial crop and the most profitable among all cultivated crops, which plays a vital role in the overall livelihood security of farm families. Diseases are the major yield constraints of crop plants. One of the most serious fungal diseases of dragon fruit is anthracnose caused by Colletotrichum species. Since less information available on anthracnose of betel vine, this study was undertaken. Methods: The efficacy of non-systemic, systemic and combination fungicides were tested against Colletotrichum gloeosporioides using poisoned food technique (Vincent 1947) under in vitro condition. Six non-systemic fungicides Chlorothalonil 75% WP, Captan 50% WP, Mancozeb 75% WP, Copper oxychloride 50% WP, Propineb 70% WP and Copper hydroxide 53.8% at (250 ppm, 500 ppm and 1000 ppm), six systemic fungicides Hexaconazole 5% EC, Propiconazole 25 % EC, Azoxystrobin 25% SC, Tebuconazole 25.9% EC, Difenaconazole 25% EC and Picoxystrobin 22.5% SC at (100ppm, 150ppm, 250ppm) and six combi fungicides Propiconazole 13.9% + Difenoconazole 13.9% EC, Tebuconazole 50% + Trifloxystrobin 25% WG, Fluropyram 200 g/L + Tebuconazole 200 g/L SC, Fluxopyroxad 250 g/l + pyraclostrobin 250g/L, Fluopyram 250 g/L + Trifloxystrobin 250 g/L SC, Azoxystrobin 16.7% + Tricyclazole 33.3% SC at (150 ppm, 250 ppm, 500 ppm) were evaluated. Results: Among six non-systemic fungicides evaluated against C. gloeosporioides which was obtained from the isolated sample and results revealed that the Copper hydroxide gave 69.90 % inhibition which was superior over all other fungicides evaluated and least inhibition was recorded with Mancozeb 40.30%. Difenconazole, Tebuconazole were the best systemic fungicides found best with inhibition % of 98.28 and 95.17 when evaluated against C. gloeosporioides. Out of the six evaluated combination products, propiconazole + difenconazole exhibited the highest inhibition rate at 99.78 %. Following closely, Fluopyram 200 g/L + Tebuconazole 200 g/L SC and Tebuconazole 50% EC + Trifloxystrobin 25% WG displayed inhibition rates of 89.47% and 87.50 % respectively.

In Vitro Evaluation of Fungicides Against Mango Anthracnose Caused by <i>Colletotrichum gloeosporioides</i>

Mango is a significant fruit crop in our country, but it is often attacked by anthracnose, a disease that causes considerable pre and post-harvest losses. There are different methods to control this disease but management through the use of various fungicides, often in combination is more suitablef, under field conditions. This study was conducted in vitro experiments using the poison food technique to induce anthracnose disease in mangoes. Efficacy of 10 different fungicides was investigated, including contact fungicides like Blitox (Copper oxychloride 50% WP) and Indofil M-45 (Mancozeb 75% WP), as well as systemic fungicides like Topsin-M 70 WP (Thiophanate-M methyl 70% WP), Amistar Top (Difenconazole @ 12.5%), Aliette (Fosetyl Aluminium 80%), Score (Difenconazole @ 25% EC), Meriman (Captan WP 50%), Tilt (Propiconazole 25% EC), mirador (Azoxystrobin @ 20%), and Native (Tebuconazole+ Trifloxystrobin 75% WG). These fungicides were tested at three concentrations (0.05, 0.1, and 0.15) to evaluate their effectiveness in inhibiting the growth of <i>Colletotrichum gloeosporioides</i>, the causal agent of anthracnose in mangoes. The results of this study showed that among the fungicides tested, Tilt (Propiconazole 25% WP), a systemic fungicide, exhibited superior inhibition, achieving complete 50 percent mycelial inhibition and preventing sporulation across all three concentrations. In contrast, Meriman (Captan WP 50%) showed the lowest inhibition, at 31.57 percent, compared to the other fungicides tested. These findings underscore the importance of selecting the appropriate fungicide for effective management of anthracnose in mango crops.

Neuroprotective effect of Withania somnifera leaves extract nanoemulsion against penconazole-induced neurotoxicity in albino rats via modulating TGF-β1/Smad2 signaling pathway

Penconazole (PEN) is a systemic triazole fungicide used to control various fungal diseases on grapes, stone fruits, cucurbits, and strawberries. Still, it leaves residues on treated crops after collection with many hazardous effects on population including neurotoxicity. Withania somnifera leaves extract (WSLE) is known for its memory and brain function enhancing ability. To evoke such action efficiently, WSLE bioactive metabolites are needed to cross the blood–brain barrier, that could limit the availability of such compounds to be localized within the brain. Therefore, in the present study, the association between PEN exposure and neurotoxicity was evaluated, and formulated WSLE nanoemulsion was investigated for improving the permeability of the plant extract across the blood–brain barrier. The rats were divided into five groups (n = 6). The control group was administered distilled water, group II was treated with W. somnifera leaves extract nanoemulsion (WSLE NE), group III received PEN, group IV received PEN and WSLE, and group V received PEN and WSLE NE. All rats were gavaged daily for 6 weeks. Characterization of compounds in WSLE using LC–MS/MS analysis was estimated. Neurobehavioral disorders were evaluated in all groups. Oxidative stress biomarkers, antioxidant enzyme activities, and inflammatory cytokines were measured in brain tissue. Furthermore, the gene expression patterns of GFAP, APP, vimentin, TGF-β1, Smad2 and Bax were measured. Histopathological changes and immunohistochemical expression in the peripheral sciatic nerve and cerebral cortex were evaluated. A total of 91 compounds of different chemo-types were detected and identified in WSLE in both ionization modes. Our data showed behavioral impairment in the PEN-treated group, with significant elevation of oxidative stress biomarkers, proinflammatory cytokines, neuronal damage, and apoptosis. In contrast, the PEN-treated group with WSLE NE showed marked improvement in behavioral performance and histopathological alteration with a significant increase in antioxidant enzyme activity and anti-inflammatory cytokines compared to the group administered WSLE alone. The PEN-treated group with WSLE NE in turn significantly downregulated the expression levels of GFAP, APP, vimentin, TGF-β1, Smad2 and Bax in brain tissue. In conclusion, WSLE NE markedly enhanced the permeability of plant extract constituents through the blood brain barrier to boost its neuroprotective effect against PEN-induced neurotoxicity.

Comparative assessment of the effectiveness of contact and systemic fungicides for treating soybean seeds in the forest-steppe of the Novosibirsk Region

Comparative assessment of the effectiveness of contact and systemic fungicides for treating soybean seeds in the forest-steppe of the Novosibirsk Region

Study on the Design, Synthesis, Bioactivity and Translocation of the Conjugates of Phenazine-1-carboxylic Acid and N-Phenyl Alanine Ester.

The natural pesticide phenazine-1-carboxylic acid (PCA) is known to lack phloem mobility, whereas Metalaxyl is a representative phloem systemic fungicide. In order to endow PCA with phloem mobility and also enhance its antifungal activity, thirty-two phenazine-1-carboxylic acid-N-phenylalanine esters conjugates were designed and synthesized by conjugating PCA with the active structure N-acylalanine methyl ester of Metalaxyl. All target compounds were characterized by 1H NMR, 13C NMR and HRMS. The antifungal evaluation results revealed that several target compounds exhibited moderate to potent antifungal activities against Sclerotinia sclerotiorum, Bipolaris sorokiniana, Phytophthora parasitica, Phytophthora citrophthora. In particular, compound F7 displayed excellent antifungal activity against S. sclerotiorum with an EC50 value of 6.57 µg/mL, which was superior to that of Metalaxyl. Phloem mobility study in castor bean system indicated good phloem mobility for the target compounds F1-F16. Particularly, compound F2 exhibited excellent phloem mobility; the content of compound F2 in the phloem sap of castor bean was 19.12 μmol/L, which was six times higher than Metalaxyl (3.56 μmol/L). The phloem mobility tests under different pH culture solutions verified the phloem translocation of compounds related to the "ion trap" effect. The distribution of the compound F2 in tobacco plants further suggested its ambimobility in the phloem, exhibiting directional accumulation towards the apical growth point and the root. These results provide valuable insights for developing phloem mobility fungicides mediated by exogenous compounds.

Efficacy of different fungicides against Ascochyta rabiei and Botrytis cinerea associated with chickpea

Ascochyta rabiei and Botrytis cinerea have been reported to cause blight and gray mold diseases in chickpea in different parts of the world and cause a significant economic loss to crop. In the present investigation, an in vitro evaluation of fungicides was conducted to find out the sensitivity and fungicide concentration in inhibiting the growth of Ascochyta rabiei and Botrytis cinerea. In vitro evaluation of fungicides revealed that, among five fungicides, bavistin (carbendazim 50 WP) a systemic fungicide was highly effective in inhibiting the mycelial growth with 100% inhibition at all the concentrations tested followed by baycor (bitertenol WP (25% w/w), with 98.88% inhibition at 500 ppm concentration and captan with 80% mycelia growth inhibition in A.rabiei. The fungicides such as chlorothalonil, copper oxychloride, and bitertanol at all concentrations were ineffective against B. cinerea. The fungicides that were effective under laboratory conditions could be further evaluated under field conditions to validate their efficacy and they could be incorporated as a component in integrated disease management in chickpea.

Isolation, identification and transcriptome analysis of triadimefon-degrading strain Enterobacter hormaechei TY18.

Triadimefon, a type of triazole systemic fungicide, has been extensively used to control various fungal diseases. However, triadimefon could lead to severe environmental pollution, and even threatens human health. To eliminate triadimefon residues, a triadimefon-degrading bacterial strain TY18 was isolated from a long-term polluted site and was identified as Enterobacter hormaechei. Strain TY18 could grow well in a carbon salt medium with triadimefon as the sole nitrogen source, and could efficiently degrade triadimefon. Under triadimefon stress, a total of 430 differentially expressed genes (DEGs), including 197 up-regulated and 233 down-regulated DEGs, were identified in strain TY18 using transcriptome sequencing (RNA-Seq). Functional classification and enrichment analysis revealed that these DEGs were mainly related to amino acid transport and metabolism, carbohydrate transport and metabolism, small molecule and pyrimidine metabolism. Interestingly, the DEGs encoding monooxygenase and hydrolase activity acting on carbon-nitrogen were highly up-regulated, might be mainly responsible for the metabolism in triadimefon. Our findings in this work suggest that strain E. hormaechei TY18 could efficiently degrade triadimefon for the first time. They provide a great potential to manage triadimefon biodegradation in the environment successfully.