Standard Fungicide Research Articles

Evaluation of Application Timing of Miravis Ace for Control of Fusarium Head Blight in Wheat

Fusarium head blight (FHB) is a serious disease of wheat and barley that not only lowers yield but also contaminates the grain with associated mycotoxins such as deoxynivalenol (DON). Chemical control options for FHB and DON include application of triazole fungicides at the anthesis or flowering stage. This presents practical challenges for growers in managing FHB, as the appropriate timing window typically lasts only 3 to 4 days. If this small window is missed, due to weather conditions or technical problems, fungicide application is less effective in controlling FHB and DON. The present work was conducted over 2 years (2019 and 2020) to test the efficacy of a new fungicide (pydiflumetofen + propiconazole) from Syngenta labeled as Miravis Ace in controlling FHB and DON content at 50% head emergence (Feekes 10.3), anthesis (Feekes 10.5.1), and end of flowering (Feekes 10.5.3) stages. Prosaro 421 SC, a standard FHB control triazole fungicide, was used at all three stages for comparison with the test fungicide. Miravis Ace application at 50% head emergence provided significant control over the nontreated check for FHB incidence (2020), FHB severity (2019), and DON content (2019) with control efficacies as high as 51, 69, and 52%, respectively. However, mean control percentages relative to the check were highest with Miravis Ace at anthesis in both 2019 and 2020 for all the FHB parameters. In conclusion, 50% head emergence provides statistically significant control on FHB and DON, but anthesis was the most effective application stage for Miravis Ace.

Isolation, Identification and Molecular Characterization of Pathogenic Fungus causing bud Rot Disease to Coconut: Its Inhibition using Silkworm Fecal Matter Mediated Synthesized Silver and Copper Nanoparticles

Coconut is one the major economic crop in India; a considerable amount of crop will be lost every year due to bud rot disease. Phytophthora palmivora is an omnipresent pathogen which causes many different diseases on a wide range of plants including bud rot of coconut. In the present investigation, we have successfully isolated bud rot disease causing fungus from the infected coconut plant samples. The isolated fungus was primarily identified by observing in microscopy further the same sample was sent for molecular identification. The presence of Phytophthora palmivora was confirmed in 18s rRNA sequencing. The growth of isolated fungus was effectively inhibited using biosynthesized Silver and Copper nanoparticles. The inhibition effects of nanoparticles against Phytophthora palmivora were observed excellent in dose-dependent manner. The silver nanoparticles synthesized using Silkworm fecal matter was shown superior inhibition activity towards Phytophthora palmivora compare to standard fungicide Fluconazole. Hence, these silver Nano particles could be successfully used in inhibiting the pathogenic fungus causing bud rot disease to coconut.

High Efficacy and Low Risk of Phytotoxicity of Sulfur in the Suppression of Strawberry Powdery Mildew

Sulfur is a multisite inhibitor of strawberry powdery mildew (Podosphaera aphanis) recommended for fungicide resistance management, yet growers may refrain from its use due to purported phytotoxicity under conditions often qualitatively defined as “hot”, or “during periods of high temperature”. Our objectives were to (i) determine phytotoxicity of sulfur on three strawberry cultivars treated in controlled environments at temperatures of 30, 35, and 40°C for periods of 1, 2, 4, and 8 h after the sulfur application; and (ii) evaluate phytotoxicity and efficacy of sulfur on strawberry grown in open fields and high tunnels in Florida. Under controlled conditions, cultivars Florida127 and Florida Beauty exhibited minor phytotoxicity when exposed to sulfur at 30°C for 2 to 8 h. Cultivar Florida Radiance, however, was more sensitive, with greater phytotoxicity as exposure time increased. We found that weekly applications of sulfur on cultivar Florida127 significantly reduced P. aphanis foliar and fruit disease as well as or better than the standard fungicide treatment, and resulted in 80 to 300% higher yields (compared with nontreated controls) in open field and high tunnel trials, respectively. Ambient temperature did not exceed 35°C in open field trials, where no phytotoxicity was observed. In the high tunnel, where only mild leaf phytotoxicity was observed, temperatures exceeded 40°C for a total of 20 h across 9 days. Our results suggest that sulfur has benefits for disease suppression and fungicide resistance management that greatly surpass the minimal phytotoxicity observed only at temperatures above 35°C for a period of at least 2 h.

Kresoxim methyl SC-a Quinone Outside Inhibitor against Major Fungal Foliar Diseases of Apple

Scab and Alternaria leaf blotch are the major destructive diseases of apple causing enormous loss to apple orchards of Kashmir and other states of India. The present study reports the bio-efficacy of kresoxim methyl 44.3 gL−1SC-a quinone outside inhibitor (QOI), against these diseases. The fungicide was evaluated at 0.03, 0.04 and 0.05 per cent concentrations at two different locations for two consecutive years (2014 and 2015) under epiphytotic conditions of Kashmir valley. The performance was compared with recommended standard fungicides viz., tebuconazole 25.9 EC, hexaconazole 5 EC and difenaconazole 25 EC at 0.05, 0.05 and 0.03 per cent concentrations, respectively, besides the water sprayed trees as check. The fungicide, during both the seasons and at both the locations, provided the best protection against scab and Alternaria leaf blotch. The trees treated with kresoxim methyl at 0.05 per cent concentration provided 97.25 and 97.70 per cent control of leaf scab incidence and intensity as against 95.72 and 97.43, 88.70 and 91.47 and 77.70 and 78.89 per cent observed in standards difenaconazole 25 EC, tebuconazole and hexaconazole respectively. The fungicide was significantly superior to standards tebuconazole 25.9 EC and hexaconazole 5 EC and was statistically at par with difenaconazole. Similarly, the fungicide gave an average fruit scab control of 98.00 and 98.48 per cent in incidence and intensity as against 97.25 and 97.60, 92.18 and 93.63, and 83.54 and 87.20 per cent recorded in standard difenaconazole, tebuconazole and hexaconazole, respectively. At 0.05 per cent concentration it performed efficiently in controlling Alternaria leaf blotch of apple with 94.65 and 95.20 per cent in incidence and intensity as against 94.65, 89.80 and 84.70 per cent in incidence with an intensity of 96.10, 90.56 and 85.03 per cent achieved with difenaconazole, tebuconazole and hexaconazole sprayed trees, respectively. Thus, based on two year data at two locations and comparison with the standards, it was concluded that use of kresoxim methyl at 0.04 to 0.05 per cent concentrations is effective in controlling leaf/fruit scab and Alternaria leaf blotch diseases of apple. Phytotoxicity study with the test fungicide carried out at 0.05 and 0.1 per cent concentrations on commercial apple cultivars (Red delicious and Red chief) during both the seasons and locations, revealed no sign of toxicity on fruits, leaves and other parts of the trees.

The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions.

Citrus black spot (CBS) is caused by Phyllosticta citricarpa, which is classified as a quarantine organism in certain countries whose concerns are that CBS-infected fruit may be a pathway for introduction of the pathogen. This study evaluated the reproductive capability and viability of P. citricarpa under simulated conditions in which the whole fruit, peel segments, or citrus pulp with CBS lesions were discarded. Naturally infected ‘Midknight’ Valencia orange and ‘Eureka’ lemon fruit, either treated using standard postharvest sanitation, fungicide, and wax coating treatments or untreated, were placed into cold storage for 5 weeks (oranges at 4 °C and lemons at 7 °C). Thereafter, treated and untreated fruit were incubated for a further 2 weeks at conditions conducive for CBS symptom expression and formation of pycnidia. The ability of pycnidia to secrete viable pycnidiospores after whole fruit and peel segments or peel pieces from citrus pulp were exposed to sunlight at warm temperatures (±28 °C) and ±75% relative humidity levels was then investigated. The combination of postharvest treatments and cold storage effectively controlled CBS latent infections (>83.6% control) and pycnidium formation (<1.4% of lesions formed pycnidia), and the wax coating completely inhibited pycnidiospore release in fruit and peel segments. Pycnidiospores were secreted only from lesions on untreated fruit and peel segments and at low levels (4.3–8.6%) from peel pieces from pulped treated fruit. However, spore release rapidly declined when exposed to sunlight conditions (1.4% and 0% after 2 and 3 days, respectively). The generally poor reproductive ability and viability of CBS fruit lesions on harvested fruit, particularly when exposed to sunlight conditions, supports the conclusion that citrus fruit without leaves is not an epidemiologically significant pathway for the entry, establishment, and spread of P. citricarpa.

Copper nanoparticles: Green synthesis and managing fruit rot disease of chilli caused by Colletotrichum capsici.

The present study was focused on synthesis and characterization of copper nanoparticles to evaluate their efficacy against fruit rot pathogen of chilli crop. The green synthesis of nanoparticles was carried out by using extracts of Eucalyptus and Mint leaves. The synthesis of copper nanoparticles was confirmed by XRD, PSA, SEM and TEM. The average size of these particles synthesized by Eucalyptus leaf extract (CuNP-E) ranged from 10 to 130 nm, while as size of Mint leaf extract synthesized particles (CuNP-M) ranged from 23 to 39 nm, thus confirming their nano size. These green synthesized copper nanoparticles were evaluated against Colletotrichum capsici where Carbendazim 50 WP @ 500 ppm and copper oxychloride 50 WP @ 2500 ppm served as standard checks. The mycelia inhibition of Colletotrichum capsici caused by copper nanoparticles was studied on PDA medium. CuNP-M @ 1000 ppm showed highest mycelial inhibition of 99.78% followed by 93.75% at 500 ppm and CuNP-E @ 1000 ppm compared to standard fungicides, carbendazim 50 WP @ 500 ppm (72.82%), and copper oxychloride 50 WP @ 2500 ppm (85.85%). The CuNP-M @ 500 ppm were significantly superior to carbendazim 50 WP @ 500 ppm and copper oxychloride 50 WP @ 2500 ppm, but was statistically at par with CuNP-E @ 1000 ppm. This shows effectiveness of much lower concentration of copper nanoparticles compared to conventional fungicides. In detached fruit method, nanoparticles applied before inoculation of pathogen showed better results with regard to incubation period, lesion number and lesion size than after inoculation of pathogen. The present study reveals a simple, convenient, non-toxic and cost-efficient technique for the synthesis of nanoparticles and their effectiveness against Colletotrichum capsici. CuNP-M first time synthesized and evaluated against Colletotrichum capsici performed better than CuNP-E.

Combining Biocontrol Agents with Chemical Fungicides for Integrated Plant Fungal Disease Control.

Feeding a rising population of currently 7.8 billion people globally requires efficient agriculture, which is preferably sustainable. Today, farmers are largely dependent on synthetic fungicides to avoid food losses caused by fungal diseases. However, the extensive use of these has resulted in the emergence of fungicide-resistant pathogens and concerns have been raised over the residual effects on the environment and human health. In this regard, biocontrol agents (BCAs) have been proposed as an alternative to standard fungicides but their disease management capacity is usually incomplete and heavily relies on uncontrollable environmental conditions. An integrated approach combining BCAs with fungicides, which is the focus of this review, is put forward as a way to reduce the fungicide doses to manage plant diseases and thereby their residue on harvested crops. In addition, such a strategy of combining antifungal treatments with different modes of action reduces the selection pressure on pathogens and thereby the chances of resistance development. However, to allow its large-scale implementation, further knowledge is needed, comprising timing, number and interval of repeated BCA applications and their compatibility with fungicides. The compatibility of BCAs with fungicides might differ when applied in a mixture or when used in alternation.

Evaluation of some pesticides of plant origin for control of anthracnose disease (Colletotrichum destructivum O’Gara) in cowpea

Abstract. Enyiukwu DN, Amadioha AC, Ononuju CC. 2021. Evaluation of some pesticides of plant origin for control of anthracnose disease (Colletotrichum destructivum O’Gara) in cowpea. Asian J Agric 5: 4-11. Anthracnose is a common disease of cowpea in many bean growing areas of the world. This study evaluated the effects of Alchornea cordifolia, Tabernaemontana pachysiphon, and Lantana camara as low-input biopesticides for control of the disease. The experiment was laid out in randomized complete block design (RCBD) made up of 14 treatments with 4 replications. The results indicated that all the plant materials irrespective of carrier solvent and concentrations of application significantly (P?0.05) minimized the incidence and severity of the disease, as well as improved the yield and yield parameters of the treated crop than the control. Amongst all evaluated dosages of the plant materials, 50-100 % concentration of L. camara gave the best disease control and yield improvement of the crop, followed by full strength of T. pachysiphon and A. cordifolia was the least. However, comparative to benomyl a standard fungicide, the plant-derived pesticides demonstrated lower fungitoxicity against the pathogen apart from 50-100 % extracts of L. camara which were statistically (P?0.05) at par with the effects of the fungicide. Therefore, all the plant extracts could be used at higher doses as prophylactics to stem the disease; however, L. camara could be applied at lower doses to achieve the same level of control. These plant materials overall could therefore contribute as effective bio-fungicides towards improving productivity of cowpea in the humid tropics.

Long-Term Impact of Chemical and Alternative Fungicides Applied to Grapevine cv Nebbiolo on Berry Transcriptome

Viticulture is one of the horticultural systems in which antifungal treatments can be extremely frequent, with substantial economic and environmental costs. New products, such as biofungicides, resistance inducers and biostimulants, may represent alternative crop protection strategies respectful of the environmental sustainability and food safety. Here, the main purpose was to evaluate the systemic molecular modifications induced by biocontrol products as laminarin, resistance inducers (i.e., fosetyl-Al and potassium phosphonate), electrolyzed water and a standard chemical fungicide (i.e., metiram), on the transcriptomic profile of ‘Nebbiolo’ grape berries at harvest. In addition to a validation of the sequencing data through real-time polymerase chain reaction (PCR), for the first-time the expression of some candidate genes in different cell-types of berry skin (i.e., epidermal and hypodermal layers) was evaluated using the laser microdissection approach. Results showed that several considered antifungal treatments do not strongly affect the berry transcriptome profile at the end of season. Although some treatments do not activate long lasting molecular defense priming features in berry, some compounds appear to be more active in long-term responses. In addition, genes differentially expressed in the two-cell type populations forming the berry skin were found, suggesting a different function for the two-cell type populations.

Synthesis, molecular modeling, TD‐DFT, antimicrobial, and in vitro therapeutic activity of new spherical nano‐sized sulfonamide imine ligands and their zinc (II) and copper (II) complexes

A series of nanometer‐sized spherical sulfonamide imine ligands HL1‐HL5 and their copper and zinc complexes were synthesized and fully characterized based on elemental analyses, spectroscopic (UV/vis, FT‐IR, NMR, EPR, SEM) studies, molar conductance and thermal analyses. Furthermore, computational studies of HL1‐HL5 were carried out by the DFT/B3LYP method. TD‐DFT, HOMO and LUMO energy values, chemical hardness, electronegativity, electrophilic index, softness, and other parameters were calculated. Screening against several pathogenic microorganisms indicated that HL1 exhibited high activity against the tested Gram‐negative bacteria relative to other analogues and the inhibition activity is greater than the standard Gentamicin. Analogously, HL2 exhibited high potent activity against the tested Gram‐positive bacteria. Copper complexes exhibited a higher potent activity than zinc analogues. Noteworthy, inhibition activity of [Cu (L3)(OAc)] complex is higher than that of the standard Ampicillin. [Cu (L2)(OAc)] complex displayed a similar activity of the standard bactericides and fungicides in use. The complexes showed appreciated values of MIC against bacterial strains: B. subtilis (MIC = 0.4 μg / mL), E. coli and S. pneumonia (MIC = 1.95 μg / mL) and P. aeruginosa (MIC = 7.81 μg / mL). in vitro cytotoxic activities study proved that [Cu (L3)(OAc)] complex exhibited appreciable activity versus (HEPG‐2); IC50 = 4.8 μg/ml, while [Cu(L2)(OAc)] complex showed a high activity against (MCF‐7); IC50 = 6.2 μg/ml. These results could be considered as new findings of promising antitumor candidates for experimental chemotherapy.

Synthesis, Characterization, and Antimicrobial Evaluation of Some New 1,4-Dihydropyridine Hybrid with 1,3,4-Thiadiazole

A synthesis of 2,2′-((2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarbonyl)bis (hydrazin-2-yl-1-ylidene))bis(N-phenylpropanehydrazonoyl chloride) (3) and studying its examining its manufactured utilities as structure hinders for novel arrangement of bis-1,3,4-thiadiazole derivatives 6a–f, 9a,b, 11, and 12 in one stage technique with great yields by reaction with different hydrazinecarbodithioate derivatives 4a–f and 7a,b. The structure of the products was built up on various analytical and spectroscopic informations. In addition, biological assessment of the acquired compounds as antibacterial and antifungal agents was accomplished and the outcomes got investigating the high potency of some of the tested compounds compared with the employed standard bactericides and fungicides. Moreover, the minimum inhibitory concentration (MIC) of the tested compounds was determined and therefore the results obtained exploring the high efficiency of a number of the tested compounds against all the tested microorganisms.

Antifungal activity against Alternaria solani and control of early blight in tomato by essential oil of bergamot orange

The early blight (caused by the fungus Alternaria solani) results in significant damage to the tomato crop, directly affecting productivity. An alternative to the frequent use of pesticides is the use of essential oils, which can act in defense against phytopathogens. The objective of this work was to evaluate the toxic activity in vitro of the bergamot orange (Citrus aurantium ssp. bergamia) essential oil against A. solani, the control of the early blight, and the activity of defense enzymes in tomatoes treated with this oil and inoculated with A. solani. Mycelial discs of A. solani were added to dishes with V8 culture media to which essential oil at concentrations of 0, 500, 1000, 1500, 2000, and 2500 µL L-1, in addition to a standard fungicide treatment (azoxystrobin + difenoconazole, 200 + 125 g L-1, respectively) was added. The Petri dishes were incubated at 25 °C in the dark. Mycelial growth was evaluated daily for 19 days, when all treatments reached maximum growth. Sporulation analysis was performed thereafter. Tomato plants were treated with bergamot essential oil, 30 days after transplanting, in the concentrations and fungicide mentioned, in the second pair of leaves. After 72 hours, the pathogen was inoculated using a spray bottle, on treated leaves (second pair of leaves) and untreated leaves (third pair of leaves). The area under the disease progress curve (AUDPC) was calculated based on five severity assessments. The activity of peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) was evaluated in leaves treated with the concentration of 2500 µL L-1 of essential oil. The concentration of 2500 ?L L-1 reduced mycelial growth and sporulation of the pathogen by 68.15% and 29.48%, respectively. In treatments with application of essential oil, lower AUDPC was observed for a concentration of 2500 ?L L-1, which was statistically similar to that observed for fungicide application, both in treated and untreated leaves. A greater activity of PPO, POX, and PAL was found locally and systemically, both in the second and third leaves, at concentration of 2500 ?L L-1. The essential oil of bergamot can be an alternative for the control of early blight in tomato.

3D Pharmacophore-based Ligand Alignment, Virtual Screening and Molecular Docking Protocols Towards the Discovery of 2-((1H-1,2,4-triazol-1- yl)methyl) Derivatives as Antifungal Inhibitors

Background: 1,2,4-Triazoles are important five-membered heterocyclic scaffolds due to their extensive biological activities. These products have been an area of growing interest to many researchers around the world as of their diverse biological activities including antifungal and antibacterial activity against broad spectrum of microbial pathogens. Methods: A series of 2-((1H-1,2,4-triazol-1-yl)methyl) derivatives was designed, synthesized and evaluated as antifungal agents against five plant pathogenic fungi (Alternaria tennis, Botryodiplodia theobromae, Fusarium moniliforme, Fusarium oxysporum and Helminthosporium turcicum) to meet the urgent need of new antifungal agents with improved activity and broader spectrum. In silico studies including pharmacophore modeling, virtual screening, drug-likeness analysis and ADMET prediction were examined. In addition, the elucidation of the activity is based on the molecular docking to the active site of the Sterol 14α-Demethylase Cytochrome P450 (CYP51) was investigated. Results: The results of antifungal activity indicated that the compounds containing tert or sec-butyl as hydrophobic substituents on a phenyl ring significantly increased the activity (compounds 4, 5 and 6) with EC50 in the range of 8-84 mg/L of all tested fungi. The pharmacophore modeling produced an accurate projecting model (Hypo 1) from these derivatives. The superlative Hypo1 consists of three features counting two hydrogen bond acceptors (HBA) and one hydrophobic (HYD). The docking results showed approximately a similar binding degree at the active sites of the fungal enzyme (CYP51) as a standard fungicide penconazole. Conclusion: According to data obtained, some derivatives, especially those with tert or sec-butyl substituents on the phenyl ring, were more potent against phytopathogenic fungi. These compounds (e.g., 4, 5, and 6) should develop into new potential fungicides as a desirable activity.

Increased triazole-resistance and cyp51A mutations in Aspergillus fumigatus after selection with a combination of the triazole fungicides difenoconazole and propiconazole

Triazole-resistance in Aspergillus fumigatus is widespread. We evaluated whether triazole-resistance in A. fumigatus and its related cyp51A mutations, induced by a combination of the triazole fungicides difenoconazole and propiconazole, differs from resistance induced by the individual fungicides. Both difenoconazole and propiconazole can induce triazole-resistance in A. fumigatus. Resistance is much easier induced by formulated fungicides or a combination of these two fungicides compared with standard fungicides or individual fungicides, respectively. Six different mutations (G138S, G138D, H147Y, I246M, M263I and D430N) were identified in the induced resistant strains. The H147Y, I246M and M263I mutations were associated with triazole-resistance. This implies that the application of a combination of difenoconazole and propiconazole may result in higher triazole-resistance in A. fumigatus and more mutations in the cyp51A gene.

Development of MgO-sepoilite Nanocomposites against Phytopathogenic Fungi of Rice (Oryzae sativa): A Green Approach.

Innovation in agriculture is a vital organ of research for sustainable food supply to the increasing global population. Organic compounds used as fungicidal agents against seed-borne pathogens are bracketed due to their toxic nature and residual effects, which are either already banned or may get banned in the near future. In this study, the surface and electric properties of nontoxic sepiolite have been blended with the antimicrobial properties of metabolizable MgO nanoforms (nMgO) as a greener alternative to prepare their nanocomposites. We compared a sepiolite-MgO (SE-MgO) nanocomposite with MgO nanoparticles in an aqua dispersed form (aqMgO-NPs) for their antifungal evaluation against various phytopathogenic fungi of rice. The SE-MgO nanocomposite was more potent in comparison to aqMgO-NPs with ED90 > 230 and 249 μg/mL, respectively, against the test fungi better than standard fungicides. Ultramicroscopic studies revealed hyphal distortion and spore collapse as the cause of antimycotic activity. The in vitro seed treatment revealed 100% hyphal reduction with SE-MgO at 250 μg/mL of MgO as an active ingredient (a.i.). MgO and sepiolite both have been regarded as safe materials by international agencies; therefore, using their nanocomposites can be an effective, sustainable, nontoxic, eco-friendly, and residue-free strategy for combating fungal menace against phytopathogens.

Structure based approach for twin-enzyme targeted benzimidazolyl-1,2,4-triazole molecular hybrids as antifungal agents

Agri-vitality of benzimidazoles and 1,2,4-triazoles against ergosterol and β-Tubulin prompted and “lead hybridization” based novel series of benzimidazolyl-1,2,4-triazoles (1–32) were designed as twin-enzyme targeted inhibitors. In silico computational tools viz. molecular docking, Lipinski parameters, Frontier molecular orbital approach and Toxicity analysis screened three benzimidazoly-1,2,4-triazoles out of 32 designed molecules, which were synthesised by multistep protocol and characterized by spectroscopic techniques. Antimycotic activity against F. verticillioides, D. oryzae, C. lunata and F. fujikuroi indicated deca fold enhanced potency of all the synthesised compounds, than the standard commercial benzimidazole fungicide, carbendazim. Compounds 8 exhibited ED50 values lower than triazole fungicide, propiconazole. Remarkably, compound 8 inflicted the most promising activity against all the test fungi with ED50 value ranging from 16 to 21 μg/ml better than the standard commercial fungicides used (Tilt: 20–25 μg/ml and Carbendazim:150–230 μg/ml). Ultra microscopic details revealed compound 8 not only caused aberrant distortions resulting in collapsed hyphae but also efficiently shrunken the spores resulting in reproduction inhibition, as possible cause of fungal growth inhibition.

Chemically induced systemic acquired resistance in the inhibition of French bean rust

IR (Induced resistance) is a security arrangement in the interior part of the plants to counterattack fungal, bacterial and viral pathogens or any pests. The apprehension has been appeared, and the system intensifies a resistance to the attack. In this research, efficacy of eight IR chemicals along with standard fungicide hexaconazole was evaluated against French bean rust with reference to alteration in biochemical constituents present in the plant under pot conditions. Minimum disease severity was recorded when plants were challenge inoculated after 20 days of treatment of IR chemicals. Minimum disease severity (8.50 %) was recorded in plants sprayed with KH2PO4 as compared to control. The application of IR chemicals triggered the activity of defence related enzymes (phenol, PO, PPO and PAL) in bean plants upon challenge inoculation with Uromyces appendiculatus. Under field conditions potassium dihydrogen phosphate sprays were found most effective in reducing the disease severity to 30.71 % followed by benzothiadiazole with 41.23 % disease severity though they were slightly less effective to standard fungicide hexaconazole.

In-vitro antifungal and anti-bacterial activity of chloroform extract from tubers of Aconitum laeve Royle: Endangered species, India

IntroductionThe antifungal and antibacterial activity of chloroform extract from tubers of Aconitum laeve growing Jammu & Kashmir belts of Himalayan region was studied. Material and methodsIn the present study, to check the antimicrobial activities of chloroform extract for antifungal assay, disc diffusion method was used which was further evaluated for their antibacterial by well diffusion method. ResultsThe extract from the Aconitum laeve tubers has shown antifungal activity with 100% mycelia growth inhibition against Rhizoctonia solani and Fusarium oxysporum was found to be 600 µg/mL; however, for Bipolaris maydis and Alternaria alternata at concentration of 1200 µg/mL. The IC50 showed a range from 298.6 µg/mL to 591.4 µg/mL as compared with standard fungicides (Amphotericin & Clotrimazole) with IC50 values ranging from 37.8 µg/mL to 65.3 µg/mL and 42.2 µg/mL to 102.7 µg/mL. The IC50 values showed a range from 313.2 µg/mL–613.4 µg/mL as compared to standard fungicides with IC50 values 39.6 µg/mL–47.3 µg/mL. The spore germination inhibition test revealed the chloroform extract as a potent inhibitor with IC50 values as 289.4 µg/mL, 315.7 µg/mL and 162.8 µg/mL for Alternaria alternata, Bipolaris maydis and Fusarium oxysporum. The Zone of Inhibition (ZOI) shown by essential oil against test bacterial strains at concentration of 600 µg/mL to Gram negative bacteria Pseudomonas aeruginosa (18.41 ± 0.03 mm), Escherichia coli (15.61 ± 0.09 mm), Salmonella typhimurium (10.72 ± 0.16 mm) Proteus vulgaris (15.27 ± 0.01 mm) and Gram positive bacteria Bacillus subtilis (13.89 ± 0.72 mm). At the same time, ZOI of standard antibiotic ciprofloxacin against test bacterial strains was Pseudomonas aeruginosa (09.6 ± 0.01 mm), Escherichia coli (14.3 ± 0.02 mm), Salmonella typhimurium (19.3 ± 0.13 mm), Proteus vulgaris (17.8 ± 0.12 mm) and Bacillus subtilis (20.6 ± 0.03 mm), respectively. ConclusionThis is the first report of biological activities on Aconitum leave.

Effect of iron sulfide nanopriming in reducing Drechslera seed rot and seedling mortality in rice

Potential of sonochemically synthesized iron sulfide aqua dispersed nanoparticles (FeS-NFs) against Drechslera oryzae causing seed rot and seedling blight in rice was examined. Stable aqua dispersed nanoparticles of FeS were prepared in situ using ferrous sulfate heptahydrate (FeSO4. 7H2O) and sodium sulfide (Na2S) via sonochemical method. SEM graphs revealed the inhibition of spore formation in Drechslera oryzae at 17μg/ml, with much higher efficacy than the standard fungicide, captan. Rice seeds primed in FeS-NFs (30μg/ml) for 8 hours showed a significant reduction of 82.12% in seed rot and 76.08% in seedling blight which was far better than that controlled by captan (63.4% and 65.21%) and hydropriming (69.2% and 63.04%). The primed seeds showed maximum germination (90±2%) with longer shoot length (11.1±1.1cm) and vigorous seedlings without any symptoms of phytotoxicity. Utilization of FeS-NFs as eco-friendly water based antifungal seed priming agent (acting as both fungicide and nutrient) can provide better alternative to organic fungicides.

Combined Effect of Spirulina Platensis and Punica Granatum Peel Extacts: Phytochemical Content and Antiphytophatogenic Activity

Biological control is one of the effective methods for managing plant diseases in food production and quality. In fact, there is a growing trend to find new bio-sources, such as marine algae and vegetal by-products. In this study, pomegranate (Punica granatum) peel (S1) and Spirulina platensis (S2) alone and in combinations, pomegranate peel/Spirulina: 25%/75% (S3) and 50%/50% (S4) were evaluated for antimycotoxigenic and antiphytopathogenic fungal properties. The chemical composition (moisture, dry matter, protein, lipid and ash) as well as total polyphenols, flavonoids and anthocyanins content were evaluated in the four extracts. Using agar diffusion and broth microdilution methods, the anti Fusarium oxysporum, Fusarium culmorum, Fusarium graminearum, Aspergillus niger and Alternaria alternata activities were measured and their correlations with phytochemical content were evaluated. Interestingly, combinations between Spirulina at 75% and pomegranate peel at 25% (S3) have a significant impact (p &lt; 0.05) on the antifungal activity compared to S1, S2 and S4. These findings underlie the effectiveness of biocontrols over standard fungicides and imply that existing methods can be further improved by synergistic effects while maintaining food safety in an eco-friendly manner.