Screening Of Fungicides Research Articles

Comparison of the Species Communities ofPhytophthora, Pythium, andPhytopythiumAssociated with Soybean Genotypes in High Disease Environments in Ohio

The roles that specific cultivars with different levels and types of resistance may play on the diversity and abundance of Phytophthora, Phytopythium, and Pythium spp. communities were compared. Three soybean cultivars were planted in a total of 11 different high disease environments in Ohio and seedlings were collected for direct isolation and amplicon sequencing of the rhizosphere soil. Plant population and yields were lower for the moderately susceptible cultivar Sloan compared with the cultivars Kottman, with high partial resistance to Phytophthora sojae, and Lorain, with high partial resistance to both Pythium spp. and Phytophthora sojae. Based on both direct isolation and amplicon sequencing, distinct communities with key indicator species were identified at each environment, including differences at 14 and 25 day after planting for two environments. The environment had the largest influence on the community composition. Soybean genotype did influence the abundance of the hemibiotroph Phytophthora sojae but not species of Phytopythium or Pythium. In addition, from all environments and cultivars, operational taxonomic units (OTUs) classified as Pythium attrantheridium, P. heterothallicum, and P. sylvaticum were always detected. This is also the first report of an OTU of P. periilum from soils and the first one to recover undescribed species that match the sequence of Pythium sp. CAL2011f from soybean seedlings in Ohio This study highlights which species to target for the identification and development of resistant cultivars or for fungicide screening.

Morphological and molecular identification of Macrophomina phaseolina in the pool of pathogens of sugar beet (Beta vulgaris) root rot : Screening of fungicides for its control

Morphological and molecular identification of Macrophomina phaseolina in the pool of pathogens of sugar beet (Beta vulgaris) root rot : Screening of fungicides for its control

In vitro management of ginger rhizome rot causing pathogen by fungicides

Ginger, a basic Indian spice widely used in Indian culinary and alternative medicines as well. An experiment on screening of fungicides against the major test pathogen Fusarium oxysporum f. sp. zingiberi was performed in vitro by poisoned food technique using contact and systemic fungicides. The fungicides tested at 24, 48, 72 and 96 h. Amid fungicides tested, carbendazim + mancozeb @ 0.15, 0.2 and 0.25%, carbendazim @0.1 and 0.15% and copper oxychloride @ 0.25% were found best in inhibiting the pathogen growth by 89.97 and 85.14 per cent respectively and recorded highest inhibition (%) over other treatments at 24h, carbendazim+mancozeb@ 0.25% noticed a significant inhibition of 89.97 per cent after 48h of incubation, similarly, carbendazim+mancozeb (0.25%) proved its inhibition ability and found with highest inhibition of 85.42, 79.42 per cent at 72h and 96h respectively over control.

Management of early blight of tomato by using different bioagents as seed dressing and its effect on germination and growth

Early blight of tomato caused by Alternaria solani (Ellis & Martin) Sorauer is one of the most destructive disease of tomato. It is a potential disease of tomato that reduces its production globally. Several management practices have been adopted so far to minimize the disease. Present study was based on screening of fungicides, bio agents and botanicals against A. solani in tomato causing early blight disease in glass house condition. Among six different treatments, T-6 treatment i.e. 2 per cent spray of mancozeb gives maximum disease control of 59.60 per cent followed by T-4 treatment having seedling treatment by Trichoderma harzianum with 50.98 per cent disease control. Disease severity was also in this study, which were 20.33 per cent given by treatment 6.

Evaluation of Sensitivity and Resistance Risk of Corynespora cassiicola to Isopyrazam and Mefentrifluconazole.

Necrotic lesions on leaves caused by Corynespora leaf spot (CLS) seriously threaten the quality and yield of cucumber in China. Corynespora cassiicola has developed different degrees of sensitivity to various fungicides due to its long-term and extensive application. In our work, the effect of isopyrazam and mefentrifluconazole on different life stages of C. cassiicola was examined. To determine the optimal effect of binary mixtures of isopyrazam and mefentrifluconazole, the two fungicides were mixed at different proportions. Furthermore, the disease suppression of isopyrazam, mefentrifluconazole, and their compound mixture against CLS was evaluated in greenhouse experiments. Ultraviolet (UV) mutagenesis and fungicide-selection methods were performed to assess the risk of resistance development. Among the three life stages tested, isopyrazam showed the weakest inhibition on mycelial growth, and mefentrifluconazole showed the strongest inhibition of germ tube elongation. According to Wadley's and cotoxicity coefficient methods, the optimal proportion of the two-component mixture of isopyrazam and mefentrifluconazole was 1:1. Isopyrazam, mefentrifluconazole, and their binary mixture at 1:1 reduced the disease severity of CLS on potted cucumber plants, with protective effects of 31.11, 24.65, and 42.12% and curative effect of 33.90, 37.48, and 42.84%, respectively. Compared with isopyrazam or mefentrifluconazole alone, the binary mixture of the two fungicides at 1:1 did not exert significant influence on the change of C. cassiicola sensitivity. Undoubtedly, such data will greatly facilitate the screening of new fungicides for CLS and resistance management.

In vitro screening of fungicides and plant extracts against six pathogenic fungi isolated from cotton (Gossypium arboreum L.) seed

Six pathogenic fungi, namely Aspergillus flavus Link., A. niger van Tieghem (Type-I)., Curvularia lunata (Wakker) Boedijn, Fusarium moniliforme var. subglutinans Wr. & Reink., Fusarium sporotrichioides Sherb., Mem. and Rhizoctonia solani J.G. Kuhn were isolated from cotton seeds. Five fungicides viz., Acrobat MZ, Autostin 50 WDG, Capvit 50 WP, Nativo 75 WP and Thiovit 80 WG were selected to evaluate in vitro efficacy at 100, 200, 300, 400 and 500 ppm concentrations against pathogenic fungi following poisoned food technique. Out of 5 fungicides Nativo 75 WP showed the complete growth inhibition of above mentioned six pathogenic fungi at all the used concentrations. Autostin 50 WDG showed complete growth inhibition of all tested pathogenic fungi except Curvularia lunata. Leaf extract of five angiospermic plants viz., Adhatoda vasica, Aegle mermelos, Azadirachta indica, Datura metel and Psidium guajava were selected to evaluate in vitro fungitoxicity at 5, 10, 15 and 20% concentrations against the test pathogens. At 20% concentration, out of the 5 plants extracts A. indica was found to be most active to inhibit the growth of Aspergillus niger (Type-I) (65.56%) and Fusarium moniliforme var. subglutinans (75.00%), Psidium guajava were most active against A. flavus (81.29%) and Curvularia lunata (72.23%), and Datura metel was most active against Fusarium sporotrichioides (64.77%) and Rhizoctonia solani (42.44%).

Non-targeted screening of triazole fungicides in tomatoes by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry

In order to cope with the differences in international trade regulations, it is necessary to establish a rapid non-targeted screening method for triazole fungicides in food. Therefore, a non-targeted method based on ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was established for the rapid screening of triazole fungicides in tomatoes. Tomato samples were extracted with acetonitrile and then purified by QuEChERS. The purified solution was separated on a BEH C18 column (100 mm×2.1 mm, 1.7 μm) using a gradient mobile phase consisting of acetonitrile and water (both containing 0.1% formic acid). Full information tandem mass spectrometry (MSE) acquisition using electrospray ion source under positive ion mode was performed. The 19 triazole fungicides were divided into eight groups based on their structural differences. The secondary mass fragments of eight typical standards in the eight groups of triazole fungicides were analyzed, and then, the regularities of the characteristic fragment ions and neutral loss fragments produced by collision-induced dissociation of the triazole fungicides were summarized. The fragmentation regularity was further verified by the other 11 triazole fungicides. A total of 16 tomato samples collected from local supermarkets in Beijing were screened using this non-targeted method. Diniconazole was identified and confirmed in one sample, which demonstrated that the method could achieve rapid and accurate non-targeted screening of triazole fungicides in tomatoes. The proposed method is highly efficient, sensitive, and accurate, thus providing a reference for screening triazole fungicide residues in food.

Five Fungal Pathogens Are Responsible for Bayberry Twig Blight and Fungicides Were Screened for Disease Control.

Bayberry (Myrica rubra) is a commercial fruit in China. For the past seven years, twig blight disease has been attacking bayberry plantations in Shantou City, Guangdong Province, China, leading to destructive damage and financial loss. In this study, five fungal species associated with twig dieback and stem blight were identified based on morphological characteristics combined with multilocus sequence analysis (MLSA) on the internal transcribed spacer (ITS) region, partial sequences of β-tubulin (tub2), translation elongation factor 1-α (tef1-α), large subunit ribosomal RNA (LSU) and small subunit ribosomal RNA (SSU) genes, which are Epicoccum sorghinum, Neofusicoccum parvum, Lasiodiplodia theobromae, Nigrospora oryzae and a Pestalotiopsis new species P. myricae. P. myricae is the chief pathogen in fields, based on its high isolation rate and fast disease progression after inoculation. To our knowledge, this is the first study reporting the above five fungi as the pathogens responsible for bayberry twig blight. Indoor screening of fungicides indicates that Prochloraz (copper salt) is the most promising fungicide for field application, followed by Pyraclostrobin, 15% Difenoconazole + 15% Propiconazole, Difenoconazole and Myclobutanil. Additionally, Bacillus velezensis strain 3–10 and zeamines from Dickeya zeae strain EC1 could be used as potential ecofriendly alternatives to control the disease.

Screening of fungicides and bio-control agents against Sclerotium rolfsii (Sacc.) causing collar rot in Lentil

Lentil is an important pulse crop, contributes about 8-9% of the total pulse production in India and is also a major source of protein, minerals and vitamins. Collar rot of lentil is an important seedling disease caused by Sclerotium rolfsii Sacc. In this study, twenty isolates (Th1-Th20) of Trichoderma harzianum, one isolate of Pseudomonas fluorescence and nine commercially available fungicides were tested in vitro for their efficacy in inhibiting the growth of the pathogen. Trichoderma harzianum isolate Th16 and Th14 were found to inhibit maximum mycelial growth of the pathogen. The complete inhibition of mycelial growth of Sclerotium rolfsii was found with Propiconazole, Tabuconazole, Hexaconazole, Ridomil and Carbendazim+ Mancozeb at all (0.03%, 0.05% and 0.1%) concentrations. Other fungicides (Captan, Mancozeb and Carbendazim) also showed significant inhibition of the mycelial growth of the pathogen. No inhibition was recorded in the treatment with copper oxychloride even at 0.2% concentration.

Heterologous expression of an alternative oxidase from Moniliophthora perniciosa in Saccharomyces cerevisiae: Antioxidant function and in vivo platform for the study of new drugs against witches’ broom disease

The fungus Moniliophthora perniciosa is the causal agent of witches’ broom disease (WBD), one of the most devastating diseases of cacao, the chocolate tree. Many strategies to control WBD have been tested so far, including the use of agrochemicals such as the strobilurins. Strobilurins are fungicides of the QoI family, and they are used in the control of a wide array of fungal diseases in many different crops, including cereals, field crops, fruits, tree nuts, and vegetables. These drugs act by specifically inhibiting fungal respiration at the Qo site of complex III, which is a component of the main mitochondrial respiratory chain. However, M. perniciosa is resistant to this family of chemicals. It has been postulated that this resistant phenotype is, at least in part, a result of the strong ability of this fungus to counteract the oxidative stress generated by the impairment of the main mitochondrial respiratory chain, through the activation of an alternative oxidase (Mp-AOX). To test this hypothesis, we expressed functional mitochondria-localized Mp-AOX in the model yeast Saccharomyces cerevisiae. We demonstrated that heterologous expression of Mp-AOX strongly inhibits hydrogen peroxide production by mitochondria. It also diminishes the total cell amount of oxidized glutathione (GSSG), resulting in a fifty-fold higher GSH/GSSG ratio in cells expressing Mp-AOX than in wild type cells. In addition, Mp-AOX activity decreases yeast growth rate and leads to low biomass production. Therefore, we propose the use of this heterologous expression system to direct the development of new inhibitors of fungal AOX by comparing the differences in optical density of Mp-AOX-expressing cells in the presence and absence of potential AOX inhibitors. Together, our results confirm the antioxidant role of Mp-AOX and provide an in vivo platform to be used in the screening of new fungicides based on Mp-AOX inhibition.

In Vitro Screening of Fungicides and Plant Extracts Against Pathogenic Fungi Associated With Infected Fruits of Carica Papaya L

Five fungicides viz., Autostin 50 WDG, Dithane M 45, Greengel 72 WP, Ridomil Gold MZ 68 WG and Tilt 250 EC exclusively were tested against three pathogenic fungi viz., Colletotrichum gloeosporioides (Penz.) Sacc., Fusarium nivale (Fr.) Ces. and Fusarium sp. associated with Carica papaya L. following poisoned food technique. At 100 ppm Autostin showed complete growth inhibition of C. gloeosporioides, F. nivale and Fusarium sp., while Tilt 250 EC showed complete growth inhibition of C. gloeosporioides at the same concentration. These fungicides at 400 and 500 ppm showed complete growth inhibition of F. nivale. Tilt 250 EC showed complete growth inhibition of Fusarium sp. at 300, 400 and 500 ppm. Eight plants extract, viz., Adhatoda vasica, Azadirachta indica, Curcuma longa, Ocimum sanctum, Lantana camara, Tagetes erecta, Thuja orientalis and Vitex negundo were also tested for their efficacy at 5, 10, 15 and 20% concentrations against these pathogenic fungi. Out of the eight plant extracts, Ocimum sanctum showed highest (88.57%) radial growth inhibition of C. gloeosporioides at 20% concentration. Curcuma longa showed highest (88.55%) radial growth inhibition of F. nivale and Adhatoda vesica showed highest (80.02%) radial growth inhibition of Fusarium sp. at the same concentrations. The present investigation suggests Autostin 50 WDG and Tilt 250 EC as best inhibiting chemical fungicides for C. gloeosporioides, F. nivale and Fusarium sp. Extracts of O. sanctum, C. longa and Adhatoda vesica were found to be superior to other plant extracts tested.
 Journal of Bangladesh Academy of Sciences, Vol. 42, No. 2, 121-128, 2018

Management of Stemphylium leaf spot (Stemphylium vesicarium) and rust (Puccinia asparagi) of asparagus (Asparagus officinalis) with cultivar selection and fungicides

Stemphylium leaf spot (SLS) and rust are foliar diseases of asparagus fern. If left unmanaged, both SLS and rust can contribute to early decline of an asparagus field and a reduction in yield in subsequent seasons. Currently, growers rely on protectant foliar fungicides and cultivar selection to control foliar disease in asparagus in Canada. However, it is unclear which new cultivars are less susceptible to foliar disease and if any new fungicides might provide adequate control. The objectives of this research were to: (1) assess cultivars and experimental breeding lines for sensitivity to foliar disease, and (2) evaluate fungicides for control of foliar disease in asparagus. A cultivar trial was established in 2011 to compare six cultivars and lines. Also in 2011, thirteen fungicides and combinations of fungicides were assessed for control of foliar disease in ‘Guelph Millennium’. In both studies, the fern was assessed for symptoms of SLS and rust. ‘Jersey Giant’ and ‘Guelph Equinox’ and lines UG010 and UG023 had lower rust severity (as measured as standardized area under the disease progress curve, sAUDPC) than ‘Guelph Millennium’ and ‘Tiessen’. ‘Jersey Giant’ also had lower SLS disease severity index (DSI) and sAUDPC than ‘Guelph Millennium’ and ‘Guelph Equinox’ and the line UG023. There was a negative correlation between SLS and rust for both sAUDPC and DSI assessments. In the fungicide screening trials, differences were observed in lesion counts and sAUDPC. In a 3-year-old field, azoxystrobin/cyproconazole, azoxystrobin/difenoconazole, benzovindiflupyr, cyproconazole, tebuconazole, and the tank-mixture of mineral oil + pigment + propiconazole had lower sAUDPC than the untreated control. In the 4-year-old field, only azoxystrobin/cyproconazole, azoxystrobin/difenoconazole, and cyproconazole had lower sAUDPC than the untreated control. Further research is warranted to investigate rust management programs with fungicides on slow-rusting asparagus cultivars.

In silico Prediction, Characterization, Molecular Docking, and Dynamic Studies on Fungal SDRs as Novel Targets for Searching Potential Fungicides Against Fusarium Wilt in Tomato.

Vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici (FOL) is one of the most devastating diseases, that delimits the tomato production worldwide. Fungal short-chain dehydrogenases/reductases (SDRs) are NADP(H) dependent oxidoreductases, having shared motifs and common functional mechanism, have been demonstrated as biochemical targets for commercial fungicides. The 1,3,6,8 tetra hydroxynaphthalene reductase (T4HNR) protein, a member of SDRs family, catalyzes the naphthol reduction reaction in fungal melanin biosynthesis. We retrieved an orthologous member of T4HNR, (complexed with NADP(H) and pyroquilon from Magnaporthe grisea) in the FOL (namely; FOXG_04696) based on homology search, percent identity and sequence similarity (93% query cover; 49% identity). The hypothetical protein FOXG_04696 (T4HNR like) had conserved T-G-X-X-X-G-X-G motif (cofactor binding site) at N-terminus, similar to M. grisea (1JA9) and Y-X-X-X-K motif, as a part of the active site, bearing homologies with two fungal keto reductases T4HNR (M. grisea) and 17-β-hydroxysteroid dehydrogenase from Curvularia lunata (teleomorph: Cochliobolus lunatus PDB ID: 3IS3). The catalytic tetrad of T4HNR was replaced with ASN115, SER141, TYR154, and LYS158 in the FOXG_04696. The structural alignment and superposition of FOXG_04696 over the template proteins (3IS3 and 1JA9) revealed minimum RMSD deviations of the C alpha atomic coordinates, and therefore, had structural conservation. The best protein model (FOXG_04696) was docked with 37 fungicides, to evaluate their binding affinities. The Glide XP and YASARA docked complexes showed discrepancies in results, for scoring and ranking the binding affinities of fungicides. The docked complexes were further refined and rescored from their docked poses through 50 ns long MD simulations, and binding free energies (ΔGbind) calculations, using MM/GBSA analysis, revealed Oxathiapiprolin and Famoxadone as better fungicides among the selected one. However, Famoxadone had better interaction of the docked residues, with best protein ligand contacts, minimum RMSD (high accuracy of the docking pose) and RMSF (structural integrity and conformational flexibility of docking) at the specified docking site. The Famoxadone was found to be acceptable based on in silico toxicity and in vitro growth inhibition assessment. We conclude that the FOXG_04696, could be employed as a novel candidate protein, for structure-based design, and screening of target fungicides against the FOL pathogen.

Standard area diagrams to aid assessments of the severity of blight leaf spot symptoms on cassava leaves

A standard area diagram (SAD) set to assess the severity of blight leaf spot (BliLS) caused by Passalora vicosae on cassava leaves was developed and validated. The proposed SAD set includes diagrams illustrating six leaves with different severities of blight leaf spot (5, 10, 20, 30, 40 and 50%). The SAD set was validated by ten raters with no previous experience in disease assessment. Lin’s concordance correlation analysis of estimated versus actual disease severity showed that the statistical parameters (υ, u, r and ρc) were improved when raters were aided by the SADs. Overall agreement measured by Lin’s concordance correlation coefficient (ρc) increased from 0.70 to 0.82, without and with SADs, respectively. Similarly, by analysing the coefficient of determination (R2) and intra-class correlation coefficient (ρ), the estimates of severity were more reliable by using the SADs. The proposed SAD set increases the accuracy and reliability of estimates of the severity of BliLS in cassava and therefore is a valuable aid for research on the epidemiology, breeding for resistance, fungicide screening and pathotype characterization.

Simple and inexpensive long-term preservation methods for Phytophthora infestans

Phytophthora infestans is one of the most notorious pathogen among Phytophthora species causing potato late blight disease. Stable and long-term preservation of this pathogen is essential for biological research and fungicide screening. The aim of this study was to find a suitable long-term preservation method for P. infestans. We adjusted the storage temperature, made a slight modification to the rye seed method, and compared the influence of four preservation methods (the mineral oil method, the sterile water method, the rye seed method, and the modified rye seed method) on survival, growth and virulence of four isolates of P. infestans. The results showed that all four methods maintained high viability of the tested P. infestans isolates, but the two rye seed methods were the best ways to maintain 100% viability of the P. infestans isolates without contamination. The four preservation methods did not significantly influence growth or morphological characteristics of the P. infestans isolates. The impacts of the four methods on the virulence of the four P. infestans isolates were isolate-specific. For isolates YF3 and 64093, all four methods were suitable for maintaining their virulence. Whilst for isolate HQK8–3, the rye seed and sterile water methods were more suitable to maintain its virulence than the other two methods. For isolate 32835, storage under mineral oil was the best method for maintaining its virulence. In view of these results, it is recommended P. infestans should be stored by several different storage methods to ensure the safety and stability of the isolates.

Assessing fungicides for seedling protection of cucumber to collar rot disease caused by Sclerotium rolfsii

Sclerotium rolfsii Sacc. is known to be a serious pathogen on many crops of economic importance including cucurbits. Due to proliferic growth and ability to forming sclerotia, this pathogen is the major constraint in successful cultivation of cucumber. The present investigation was thus carried out to evaluate the potential of nine different fungicides i.e. carbendazim, thiophenate methyl, vinclozoline, captan, copper oxychloride, mancozeb, hexaconazole, mycobutanil and propiconazole at different concentrations of 10, 50, 100 and 150 ppm, on the growth inhibition of S. rolfsii . The primary assessment was made on in vitro screening of fungicides and its concentration whereby hexaconazole at lowest concentration (10 ppm) rendered the most vital effect (P≤0.0001) on growth reduction ability followed by propiconazole and mycobutanil. No growth of S. rolfsii observed on plates amended with hexaconazole when the concentration was further increased. Similar effect was traced in an experiment conducted on root trainer. The percent infected plant also provided the same impact of fungicides received in toxic-assay experiment. Maximum seedlings protection of cucumber was achieved through seed application of hexaconazole even at lowest concentration (P≤0.01); similarly, no mortality was detected on higher concentration of this fungicide. Although our result directly claiming the best effect of hexaconazole but we propose to use a combination of fungicides from different groups in order to avoid resistance development in S. rolfsii against a particular fungicide. A combination of carbendazim and hexaconazole is hereby proposed for seedling protection of cucumber to S. rolfsii .

Fungicidal screening of novel halogenated schiff bases derived secondary amines against Rhizoctonia bataticola and Macrophomina phaseolina

Novel N-alkyl-N-[1-(5-fluoro-2-hydroxyphenyl)ethyl]amines and N-alkyl-N-[1-(3, 5-dichloro-2-hydroxyphenyl)ethyl] amines were synthesized as new agricultural pests controlling agents. Novel halogenated Schiff bases derived secondary amines were screened for in vitro fungicidal bioassay by poison food technique and the results thus obtained showed promising fungicidal activity against two important plant pathogenic fungi viz. Rhizoctonia bataticola and Macrophomina phaseolina. Fungicidal bioassay revealed that compound 6f was found to be most active against both R. bataticola and M. phaseolina (IC = 100%), followed by 6d (IC = 97.7% against R. bataticola and IC = 95.1% against M. phaseolina) and 6g (IC = 97.0% against both R. bataticola and M. phaseolina) in case of fluoro derivatives. Dichloro derivatives showed lesser activity against these pathogens with 7b as most active (IC = 73.3% against R. bataticola and IC = 63.3% against M. phaseolina).

Simultaneous Determination and Investigation of Nine Fungicides in Fruits Using Diethylenetriamine-Functional Magnetic Core-Shell Polymer Modified Graphene Oxide as an Efficient Adsorbent Coupled to UPLC-HRMS.

In this study, diethylenetriamine-functional magnetic core-shell polymer modified graphene oxide (DETA-MPs-GO) was prepared via precipitation polymerization and amidation reaction, and it was characterized by transmission electron microscopy (TEM), Fourier-transformed infrared spectroscopy (FTIR), and X-ray diffractometer (XRD). Subsequently, a magnetic solid-phase extraction (MSPE) procedure was applied to the as-synthesized DETA-MPs-GO for the detection of nine fungicides in fruit samples, prior to ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The homogenized fruit samples, spiked with D-labelled internal standards, were firstly extracted by 5 mL of acetonitrile twice and then purified by DETA-MPs-GO adsorbents. The optimization of the adsorption and elution conditions of DETA-MPs-GO toward fungicides was carried out to attain a satisfactory adsorption performance and desorption efficiency. The adsorption mechanism was carefully investigated, and the results revealed that a synergistic adsorption mechanism, including hydrogen bond and a π–π stacking interaction, was confirmed. Moreover, the limits of quantitation (LOQs) of the proposed approach were in the range of 0.01 to 0.30 μg/kg under the optimum conditions. The average recoveries at three spiking levels were 84.9% to 105.2%, with relative standard deviations (RSDs) varying from 0.8% to 8.2% (n = 6). The developed method was successfully utilized for the screening and detection of fungicides in 81 fruit samples purchased from markets. A detailed survey was carried out about the concentration distribution, types of fungicides, and combined use of fungicides in different fruits.

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Evaluation of the antagonistic effect of different plant species on white root disease causing fungus: <em>Rigidoporus microporus</em>

Antagonistic effect of some locally available plant spp. on Rigidoporus microporus (Fr.) Overeem, which causes white root disease was tested in vitro and in the field. As in vitro tests, Poisoned Food Technique (PFT) and Soil Fungicide Screening Test (SFST) were used. In the field study, the plant species were established in plots and were inoculated with Rigidoporus microporus. The innoculum potential of the soil of each plot was assessed after a certain period of time. Among the nine species used, several species showed antagonistic action over Rigidoporus microporus at in vitro tests, while Alpinia galanga L. (Galangale) showed the most significant inhibitory effect. In the field trial, the plot with Alpinia galanga showed a significantly low innoculum potential. Alpinia galanga has the potential to be developed as an antagonistic agent against the white root disease.