Manganese Phosphite Research Articles

Alternative products for controlling Sclerotinia sclerotiorum in vivo AND in vitro in canola crops

Products that activate plant defense mechanisms, such as white mold, may increase the disease control spectrum in canola crops as an alternative to chemical control for disease management, aiming at lower environmental impacts and selection pressure on pathogens. This study evaluated Sclerotinia sclerotiorum control and resistance induction in canola crops with alternative products. In vitro and detached leaf experiments were conducted in a laboratory, and in vivo experiments occurred in a greenhouse. High Roots®; V6®; Maxi Flor®; Wert Plus®; potassium, manganese, and copper phosphites; manganese; procymidone fungicide; and Ascophyllum nodosum, Bacillus subtilis, and Bacillus thuringiensis extracts assessed S. sclerotiorum mycelial growth in vitro in detached leaves, white mold severity in a greenhouse, and enzymatic analysis in leaf tissues. The last two experiments also received the acibenzolar-S-methyl and Trichoderma asperellum treatments. S. sclerotiorum mycelial growth showed 100% inhibition under B. subtilis and Wert Plus® at 1000 ppm and procymidone at 100 and 1000 ppm in vitro. The procymidone and B. subtilis treatments in detached leaves inhibited 100% of fungus growth. The greenhouse experiments with lower severity were procymidone, copper phosphite, B. thuringiensis, B. subtilis, manganese phosphite, potassium phosphite, High Roots®, and V6®. Higher peroxidase enzyme activity occurred in plants treated with acibenzolar-S-methyl, copper phosphite, and fungicide 48 hours after pathogen inoculation. The polyphenol oxidase enzyme did not show activity. Alternative products were responsive and may aid the chemical control of white mold in canola crops.

Glyphosate combined with manganese phosphite reduces charcoal rot severity in soybean

Macrophomina phaseolina is the causal agent of charcoal rot in soybean and causes yield losses. Glyphosate herbicide can immobilize micronutrients like manganese and iron, thus heightening plant susceptibility to diseases. Phosphites (Phi) are elicitors which also act as fungicides and can potentially contribute nutrients. The effects of glyphosate (Gly), manganese phosphite (MnPhi), and their combination (Gly + MnPhi) on the in vitro growth of M. phaseolina mycelium and the severity of charcoal rot in glyphosate-resistant soybean plants. Results showed that MnPhi had the lowest mean IC50 at 288 ppm, while the Gly + MnPhi had the highest mean IC50 at 406 ppm. Gly + MnPhi showed a 31% reduction in charcoal rot severity in the roots compared to the untreated control. Since both active ingredients in Gly + MnPhi can translocate to the roots, this treatment holds potential in controlling charcoal root disease.

Synthesis and Fluorescence Properties of Novel Ce3+-doped Manganese Phosphite Open-framework Materials

Synthesis and Fluorescence Properties of Novel Ce3+-doped Manganese Phosphite Open-framework Materials

Physiological and biochemical responses of tomato plants to white mold affected by manganese phosphite

AbstractConsidering the potential of white mold, caused by the fungus Sclerotinia sclerotiorum, to reduce tomato production, this study aimed to determinate the effect of manganese (Mn) phosphite on the resistance of tomato plants to this disease by assessing the photosynthetic performance (gas exchange and chlorophyll a fluorescence), the activities of defence enzymes and those related to the antioxidant metabolism as well as the concentrations of photosynthetic pigments, malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2−). The in vitro assays showed that S. sclerotiorum mycelial growth was inhibited by Mn phosphite in a dose‐response manner. The spray of Mn phosphite reduced white mold severity on the leaves of tomato plants. Additionally, there was a higher foliar Mn concentration for plants sprayed with Mn phosphite. The negative effects of S. sclerotiorum infection in the photosynthetic process were mitigated by Mn phosphite application as noticed by the net carbon assimilation rate, stomatal conductance to water vapour, transpiration rate, maximal photosystem II quantum yield values and concentration of photosynthetic pigments. The concentrations of MDA, H2O2 and O2‐ on inoculated leaves were lower upon Mn phosphite spray. In general, the activities of defence enzymes and those related to the antioxidant metabolism were higher for water‐sprayed plants inoculated with S. sclerotiorum in comparison to those inoculated and sprayed with Mn phosphite. Based on the present study results, the application of Mn phosphite may represent a feasible alternative for white mold management in tomato plants.

Phosphites of manganese and zinc potentiate the resistance of common bean against infection by Xanthomonas axonopodis pv. phaseoli

AbstractCommon bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli var. fuscans (Xapf), negatively impact common bean production globally. Considering the potential of phosphites to protect plants against different diseases, this study investigated the potential of using manganese (Mn) and zinc (Zn) phosphites in common bean for CBB control. Plants were inoculated with Xapf 48 hr after being sprayed with water (control) and solutions (7.5 ml/L) of Mn and Zn phosphites. The area under common bacterial blight progress curve (AUCBBPC) was significantly lower by 34% and 59% for Mn and Zn phosphite treatments in comparison with the control treatment. The AUCBBPC was significantly reduced by 38% for Zn phosphite‐sprayed plants compared to Mn phosphite treatment. Phosphite‐sprayed plants displayed higher values for area under the curves of net CO2 assimilation rate, stomatal conductance to water vapour, transpiration rate and internal‐to‐ambient CO2 concentration ratio than non‐sprayed plants. This indicates the effect of Mn and Zn phosphites in attenuating the photochemical dysfunctions caused by Xapf infection. Moreover, plants sprayed with Mn phosphite displayed higher values for area under the curves of efficiency in capturing the excitation energy of open reaction centres of PSII and electron transport rate than those non‐sprayed indicating their capacity to preserve the capture and the use of the collected energy more efficiently. Lower AUCBBPC for Zn phosphite‐sprayed plants resulted in higher concentrations of total chlorophylls. The Zn phosphite‐sprayed plants showed higher values for area under the curves of β‐1,3‐glucanase, phenylalanine ammonia‐lyase, polyphenoloxidase, ascorbate peroxidase and superoxide dismutase activities. The Zn phosphite spray primed the plants to enhance their defence response and antioxidant capacity to reduce Xapf‐triggered oxidative stress with the preservation of the photosynthetic apparatus more efficiently.

Physiological and biochemical responses of soybean to white mold affected by manganese phosphite and fluazinam

White mold, caused by Sclerotinia sclerotiorum, is one of the most important diseases affecting soybean and its control has been difficult to achieve. This study aimed to investigate the potential of manganese (Mn) phosphite and fluazinam in protecting soybean plants against S. sclerotiorum infection by examining the photosynthetic performance (leaf gas exchange and chlorophyll (Chl) a fluorescence parameters), activities of defense enzymes [chitinase (CHI), β-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO)] as well as those related to the antioxidant metabolism (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX)) and the concentrations of hydrogen peroxide (H2O2), superoxide (O2−), and malondialdehyde (MDA). White mold development was completely inhibited by fluazinam. Soybean metabolism was not changed by fluazinam. White mold severity was significantly reduced on plants sprayed with Mn phosphite, which showed a better photosynthetic performance than the non-sprayed plants. Mycelial growth of S. sclerotiorum was inhibited by Mn phosphite. Activities of CAT, POX, and SOD decreased while CHI, GLU, and PAL activities increased at 96 hai for Mn phosphite-sprayed plants compared to non-sprayed plants. In conclusion, Mn phosphite affected white mold development and pathogen-induced physiological impairments in soybean leaflets due to its dual mode of action.

Foliar fertilizers for the management of phoma leaf spot on coffee seedlings

AbstractThe growing demand for alternative strategies for plant disease management has sought a reduction in the use of fungicides via the employment of resistance inducers and foliar fertilizers, among others. Therefore, this study aimed at evaluating the following foliar fertilizers for the management of phoma leaf spot: a foliar fertilizer based on macro‐ and micronutrients (Fmm: 10% N, 4% S, B, 5% Fe and 5% Zn); one based on cobalt and molybdenum (Fcm: 2% Co and 3% Mo); manganese phosphite (FMn: 30% P2O5 and 9% Mn); and the FMn+Fmm, Fcm+Fmm and FMn+Fcm+Fmm associations compared to a boscalid fungicide and a control with no treatment. The disease severity, the chlorophyll a and b contents, the net photosynthetic rate (LPR), the phenylalanine ammonia lyase (PAL) activity and the lignin content in leaves were assessment. Based on the severity, the area under the disease severity progress curve (AUSPC) and the efficiency of disease control in relation to untreated plants were calculated. The experimental design was in randomized blocks with eight treatments and three replications. Treatments FMn+Fmm and Fcm were the most effective in reducing the AUPSC in comparison with the control and promoted an increased activity of PAL. FMn was the treatment that promoted the highest increase in the LPR. There were no effects of the treatments on the lignin content compared to the control.

K2MnII2(H2O)2C2O4(HPO3)2: a new 2D manganese(ii) oxalatophosphite with double-layered honeycomb sheets stabilized by potassium ions

A novel 2D manganese(ii) phosphite containing oxalate bridges with double layered honeycomb sheets encouraged us to propose a new structural classification for metal oxalatophosphites with anionic frameworks.

Solvothermal synthesis, crystal structures and characterization of open-framework metal (CoII and MnII) phosphites with helical channels and 16-membered rings

Two new 3D open-framework metal phosphites [(CH3)2NH2]2Co3(HPO3)4 (1) and [(CH3)2NH2]2Mn3(HPO3)4 (2) have been solvothermally synthesized. Single-crystal X-ray diffraction analysis shows that complexes 1 and 2 are isomorphic structures, with left/right-handed helical channels and 16-membered ring channels. Complex 2 represents the first monometallic four-coordinate manganese phosphite. These two phosphite complexes 1 and 2 display antiferromagnetic behavior.

An open-framework manganese(ii) phosphite and its composite membranes with polyvinylidene fluoride exhibiting intrinsic water-assisted proton conductance.

Proton conducting materials have important technological applications as key components in electrochemical devices, including fuel cells, electrochemical sensors, electrochemical reactors and electrochromic displays. And the exploration of novel proton conducting materials is significant for the development of efficient electrochemical devices. In this study, we have investigated the proton conductance of an open-framework manganese(ii) phosphite, (NH4)0.59(H3O)1.41Mn5(HPO3)6 (1). The open-framework manganese(ii) phosphate shows superior water-stability and excellent thermal stability. There was intrinsic water-assisted proton conductivity with σ = 3.94 × 10-4 S cm-1 at 328 K and 98% RH. Furthermore, composite membranes have further been fabricated using polyvinylidene fluoride (PVDF) and 1, labeled as 1@PVDF-X, where the symbol X represents the mass percentage of 1 (as X%) in the composite membrane and X = 10-55%. The composite membranes display good mechanical performance and durability for practical applications, and the proton conductivity of 1@PVDF-55 reaches 3.32 × 10-5 S cm-1 in deionized water at 336 K.

In vitro antifungal/fungistatic activity of manganese phosphite against soybean soil-borne pathogens

Soybean root and stem rots caused by soil-borne pathogens are diseases commonly found in soybean fields, and one of the most important causes of crop losses. In the present study, the mycelial sensitivity of Fusarium virguliforme, F. tucumaniae, Sclerotin ia sclerotiorum and Macrophomina phaseolina was evaluated on potato dextrose agar media (25 mL) supplemented with different concen trations of manganese phosphite (MnPhi) diluted in water (0, 25, 37.5, 50, 100, 200, 300, 400, 500, 800 and 1000 µg/mL). Mycelial growth sensitivity was analyzed using logarithmic linear regression analysis. The MnPhi concentration needed to inhibit 50% of the my celial growth (IC50) ranged from 105 µg/mL (Fusarium spp.) to 409 µg/mL (M. phaseolina). Sclerotia were completely inhibited at 500 µg/mL. The results of our study represent the first report on the di rect in vitro fungicidal/fungistatic action of MnPhi against fungi that are causal agents of soil-borne diseases.

Manganese Phosphite in Coffee Defence against Hemileia vastatrix, the Coffee Rust Fungus: Biochemical and Molecular Analyses

AbstractPhosphites (Phi) are inorganic salts of phosphorous acid that have been used as resistance elicitors to activate mechanisms underlying plant defence. This study assessed the effectiveness of manganese phosphite (MnPhi) for the management of rust (Hemileia vastatrix) on coffee seedlings. The effect of this compound on the induction of resistance was also measured by the expression of defence‐related genes such as POX (peroxidase), CAT (catalase), GLU (β‐1.3‐glucanase) and PAL (phenylalanine ammonia‐lyase) and by the activity of defence enzymes such as ascorbate peroxidase (APX), superoxide dismutase (SOD) and polyphenol oxidase (PPO). Foliar sprayings of MnPhi on coffee seedlings provided 63% control of rust severity. This compound induced defence responses in seedlings with increased transcription of genes POX, CAT, GLU and PAL in non‐inoculated plants and increased activity of APX, SOD and PPO enzymes in plants inoculated with H. vastatrix and in non‐inoculated plants. It is suggested that MnPhi can induce resistance in coffee seedlings.

ChemInform Abstract: Ionothermal Synthesis and Magnetic Study of a New Manganese(II) Phosphite with an unprecedented Mn/P Ratio.

AbstractThe layered Mn(II) phosphite (NH4)4[Mn4(PO3H)6] is prepared by ionothermal reaction of MnCl2·4H2O, H3PO3, and NH4F using 1‐pentyl‐3‐methylimidazolium bromide ([pmim]Br) as the solvent (autoclave, 150 °C, 7 d, ≈70% yield).

Ionothermal synthesis and magnetic study of a new manganese(ii) phosphite with an unprecedented Mn/P ratio

A new layered manganese(ii) phosphite, JIS-10, has been synthesised ionothermally; its structure features antiferromagnetic manganese dimers with S = 5/2.

Evaluation of native bacteria and manganese phosphite for alternative control of charcoal root rot of soybean

Plant growth promoting rhizobacteria (PGPR) are potential agents to control plant pathogens and their combined use with biopesticides such as phosphites may constitute a novel strategy to incorporate in disease management programs. In the present study, 11 bacterial isolates were selected on the basis of their antagonistic activity against Macrophomina phaseolina in dual-culture tests, and their plant growth promoting traits. Selected isolates were characterised on the basis of auxin and siderophore production, phosphate solubilisation and rep-PCR genomic fingerprinting. Two of these isolates, identified as Pseudomonas fluorescens 9 and Bacillus subtilis 54, were further evaluated for their inhibitory capacity against M. phaseolina using in vitro (on soybean seeds) and in vivo (greenhouse assay) tests. Both bacteria were applied individually as well as in combined treatment with manganese phosphite as seed treatments. Damage severity on soybean seeds was significantly reduced, compared with the untreated control, by both bacterial strains; however, the individual application of phosphite showed to be least effective in controlling M. phaseolina. Interestingly, the phosphite treatment improved its performance under greenhouse conditions compared to the results from the in vitro assays. In the greenhouse trials, the greatest reductions in disease severity were achieved when strain P. fluorescens 9 was applied singly or when strain B. subtilis 54 was combined with manganese phosphite, achieving 82% of control in both cases. This work is the first to report the control of M. phaseolina using combined treatment with PGPR and phosphite under greenhouse conditions.

Resistance inducers in the control of root lesion nematodes in resistant and susceptible cultivars of maize

Pratylenchus brachyurus stands out among the major importance nematodes for the national agriculture, due your difficulty of control. Thus, the study aimed to evaluate the efficiency of resistance inductors in the nematode management in resistant and susceptible maize. It was studied the inductors acibenzolar-S-metil, Ecolife™ and manganese phosphite. The experiment was conducted in a factorial arrangement (2 × 4) composed for two maize genotypes (resistant and susceptible to nematode). Each inductor was applied, singly, seven days and one day before inoculation and seven days after inoculation to nematode. Untreated plants were used as control. The inductor Acibenzolar-S-metil was efficient to reduce the nematode population in both genotypes. Ecolife™ promoted the nematode reduction in susceptible genotype while the results were variable for manganese phosphite. In general, the inductors showed no significant effect on plant development and the same factor mainly affected by genotype.

Suppression of Rust and Brown Eye Spot Diseases on Coffee by Phosphites and By‐products of Coffee and Citrus Industries

AbstractThe rust and brown eye spot, caused by Hemileia vastatrix and Cercospora coffeicola, respectively, are the most important fungal diseases on coffee in South America. Their management is mainly by chemical treatment, and there is no genetic resistance to brown eye spot known so far. Considering the need for developing alternative products for their control, the goal of this work was to evaluate the effects of phosphites and by‐products of coffee and citrus industries on rust and brown eye spot. Formulations of coffee and citrus industry by‐products, phosphites and their combination with fungicide were evaluated in field experiments, and their effect on fungal urediniospores and conidia was evaluated in vitro. In the field, treatments were applied individually or in combination and the in vitro assays were performed with manganese phosphite (Reforce Mn), potassium phosphite and citrus industry by‐product (Fortaleza), copper phosphite and coffee industry by‐product (Fitoforce Full), and fungicide. The severity and incidence of rust and brown eye spot on coffee leaves, yield, and leaf retention were evaluated in the field. Percentage of spore germination was evaluated in vitro for both fungi, whereas mycelial growth was evaluated for C. coffeicola only. The treatments Fortaleza, Reforce Mn and Fitoforce Full suppressed both diseases with a reduction in defoliation. In the year 2012, the plants treated with Reforce Mn and Reforce Mn + Fortaleza showed a yield increase of 72 and 88%, respectively, which was similar to the results shown by the fungicide treatment. In vitro inhibition of germination of H. vastatrix urediniospores and of C. coffeicola conidia was observed and suggests that the products exert some toxic effects to both fungi. Finally, the results observed indicate that the combined use of by‐products of plant‐processing industries and phosphites is an alternative and can be added efficiently to the management of coffee diseases.

Inductors of Resistance and Their Role in Photosynthesis and Antioxidant System Activity of Coffee Seedlings

We investigated the effects of formulations based on phosphite products on gas exchange and activity of antioxidant enzymes in coffee plants. Seedlings of the Mundo Novo cultivar were submitted to various treatments composed of different formulations of with potassium phosphite (ADB 120), manganese phosphite (Reforce Mn), and fungicide (PrioriXtra&reg). For coffee seedlings, the combination of potassium phosphite and citrus by-products, isolated or in a combination with other products elicited the antioxidant system. Besides the high activity of antioxidant enzymes, the photosynthetic rates were higher than other treatments. The better performance of coffee seedlings treated with those formulations occurred even in absence of pathogens.

Mn(HPO 3): A new manganese (II) phosphite with a condensed structure

A new manganese (II) phosphite with the formula Mn(HPO 3) has been synthesised under mild hydrothermal conditions and autogenous pressure. Large pink coloured single crystals were obtained, allowing the resolution of the structure by x-ray diffraction. Mn(HPO 3) crystallises in the P2 1/ c monoclinic space group with a=8.036(3) Å, b=8.240(3) Å, c=10.410(3) Å, β=124.73(3)° and Z=8. The structure consists of a three-dimensional, compact framework of edge sharing MnO 6 octahedra linked to phosphite groups via oxygens. The presence of the phosphite anion has been confirmed by IR spectroscopy. Mn(HPO 3) presents a high thermal stability limit of 580 °C, before rapid transformation to Mn 2P 2O 7 occurs. Photoluminescence and diffuse reflectance spectroscopy studies show the presence of high spin Mn(II) in significantly distorted octahedral coordination with Dq and Racah parameters of Dq=820, B=910 and C=3135 cm −1. The ESR spectra, performed at different temperatures, are isotropic with a g-value of 2.00(1). Magnetic measurements indicate global antiferromagnetic interactions with a ferromagnetic transition at 15 K, attributed to a canting of the antiferromagneticaly aligned spins.

A New Layered Inorganic−Organic Hybrid Manganese(II) Phosphite: (C2H10N2)[Mn3(HPO3)4]. Hydrothermal Synthesis, Crystal Structure, and Spectroscopic and Magnetic Properties

A new manganese(II) phosphite templated by ethylenediamine has been prepared by hydrothermal synthesis and characterized by X-ray diffraction data and spectroscopic techniques. A study of the evolution of the synthetic process suggests the presence of a manganese(II) phosphite as intermediate in the first steps of the reaction. The (C2H10N2)[Mn3(HPO3)4] compound crystallizes in the triclinic space group P-1 with a = 5.459(1) A, b = 5.460(2) A, c = 14.194(5) A, α = 80.65(2)°, β = 85.41(1)°, γ = 60.04(2)°, V = 361.7(2) A3, and Z = 1. The compound exhibits a layered structure along the c axis with the ethylenediammonium cations located between the sheets. Within the layers the face-sharing MnO6 octahedra give rise to trimeric entities which are interconnected by HPO3 tetrahedra. Studies of luminescence and diffuse reflectance spectroscopies have been carried out. The values of the Dq = 875 cm-1 and Racah parameters, B = 660 and C = 3160 cm-1, have been calculated. The ESR spectra at different temperatures sh...