Application Of Phosphite Research Articles

Cobalt associated with potassium phosphite improves the post-harvest quality of mango cv. Palmer

Mango is a highly perishable climacteric fruit with a short post-harvest period. Therefore, to extend shelf life, the mangoes were treated pre-harvest with a potassium phosphite solution (1.4 g/mL KH2PO4) and a control solution (0 g/mL KH₂PO) associated with different doses of cobalt (0; 48; 64; 80; 112 ml.plant-1) at a density of 1.30 g/mL. The work measured physical, chemical, and biochemical variables. Cobalt and potassium phosphite favored maintaining color and firmness and reduced the respiratory rate. The treatments significantly affected the chemical variables, reduced the soluble solids content, conserved ascorbic acid, and preserved the pH. Foliar application of cobalt and potassium phosphite at pre-harvest is an efficient technique for improving shelf life and maintaining mango quality during storage at room temperature.

Mitigation of disease and browsing impacts, and translocation, supports post-fire threatened flora recovery

Context For plant species that have evolved in fire-prone environments, declines after wildfires are often driven by the combination of fire and other threatening processes. Mitigating the impacts of these threatening processes can sometimes effectively support post-fire population recovery. Aims We test the effectiveness of: (1) phosphite application to mitigate Phytophthora dieback; (2) fencing to exclude browsing by mammalian herbivores; and (3) translocation to sites where threats can be practically managed, for conservation of threatened flora affected by wildfires in 2018 and 2019 in the Stirling Range (Koi Kyeunu-ruff), south-western Australia. Methods Survival of Phytophthora-susceptible flora was compared in repeatedly sampled plots from prior to and after wildfire and ± recurrent phosphite application. Survival and growth of browsing-susceptible flora was compared post-fire in fenced and control plots. Survival, growth and flowering was compared between wild populations recruiting after wildfire and translocated populations. Key results Phosphite application increased survival of most Phytophthora-susceptible flora. Fencing led to greater growth and often increased survival. Translocated populations, with supplemental water, had greater growth rates and earlier flowering than wild populations, and a non-significant trend for higher survival. Conclusions These findings provide strong evidence supporting continuation of phosphite application, herbivore exclusion and translocation for post-fire recovery of the threatened flora of the Stirling Range. Implications With increasing wildfire extent, frequency and impact across the globe, successful management of non-fire threats will be crucial for post-fire conservation of threatened flora, with the approaches proving effective in this study likely to have conservation value elsewhere.

Exploring Novel Management Methods for Beech Leaf Disease, an Emerging Threat to Forests and Landscapes

Exploring Novel Management Methods for Beech Leaf Disease, an Emerging Threat to Forests and Landscapes

HLB Progress and Yield Sustainability in Mature Sweet Orange Orchards Treated with Nutritional and Elicitor Products

Although the implementation of area-wide inoculum reduction and Asian citrus psyllid control are decisive in controlling Huanglongbing (HLB) epidemics, growers continue looking for enhanced nutritional and/or resistance inducer (ENRI) treatments to mitigate yield damage in HLB-affected trees. Therefore, an experiment was set up in an 8-year-old sweet orange orchard to evaluate the effects of the foliar application of nutrients, phosphite, and salicylate sprayed four to five times per year during flushing periods. The trial had eight treatments in four randomized blocks. HLB incidence and yield were assessed from December 2010 to January 2017. HLB-symptomatic trees with less than 5% HLB severity were selected from each plot in the first (Group 1), second (Group 2), and third years (Group 3) after the beginning of treatments to assess the frequency of trees with different HLB symptoms and micronutrient deficiencies, HLB severity, and fruit yield until January 2017. Twenty asymptomatic trees from each plot were also harvested for comparison each year. ENRI treatments did not reduce the progress of HLB incidence in the plots or the HLB severity progress or frequency of HLB symptoms in the selected trees. ENRI treatments did not improve the yield of symptomatic trees compared with asymptomatic trees. Hence, in a scenario without HLB-symptomatic tree removal in mature orchards, disease severity progress and yield reduction in HLB-affected trees remained regardless of ENRI treatment. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Potassium phosphite in the management of green mold in citrus

Orange is among the main produced species in citriculture, a widely important area of Brazilian agrobusiness. However, postharvest diseases, particularly the green mold caused by Penicillium digitatum, result insignificant losses in the sector. Given that chemical control is still the primary type of disease management, it is vital to create varied control methods to combine disease management programs. In this context, this study aimed to apply an alternative product based on potassium phosphite and evaluate its effect on the control of green mold and the quality of postharvest oranges.'Valencia' orange trees were treated with water (control), potassium phosphite (19.5 mL L-1), and benzimidazole fungicide (at the manufacturer's recommended dosage) at the first step of this work. The frequency and severity of green mold in the fruits were evaluated in the second step. The third step involved determining the physicochemical characteristics, which included peel and pulp color, pulp firmness, pH, titratable acidity, soluble solids, and ratio (SS/AT). Green mold incidence was reduced in oranges treated with fungicide and potassium phosphite, although the pathogen was not entirely inhibited. The effects of the potassium phosphite and fungicide treatments in oranges were similar in the area under the disease progress curve. The preharvest application of potassium phosphite (19.5 mL L-1) reduced the incidence of green mold in postharvest oranges without affecting the physical and chemical characteristics of the fruits, proving that the use of the alternative product can be a promising substitute.

Foliar application of manganese sources on glyphosate-resistant soybean in no-tillage

The glyphosate herbicide when applied in post-emergence in transgenic soybean can influence manganese (Mn) nutrition, with differentiated response when parceled out. The objective of this study was to evaluate the soybean response to Mn sources applied via leaf, in different phenological stages. Two experiments were carried out in areas with different Mn contents in the soil, using four Mn sources, sulphate and nitrate (experiment A), phosphite and Mn-EDTA (experiment B). Leaf application of Mn was done at V8 and V12 (150+150 g ha-1), V8 (single application at 300 g ha-1) and V12 (single application at 300 g ha-1). In experiment A, the plants treated with nitrate, in split application, had greater leaf area and height of insertion of the first pod. The nitric source resulted in higher soybean yield when applied at V12. On the other hand, sulphate provided plants with higher height at harvest and higher yield with split application. In experiment B, it was found a larger leaf area with application of Mn-EDTA in V12. The application of phosphite provided higher at harvest height when applied in V8 and higher leaf Mn content when applied in V12. The insertion of the first pod was lower in plants treated in V12 with phosphite or with Mn-EDTA and V8. The Mn-EDTA source resulted in higher yield of transgenic soybeans at a dose of 300 g ha-1, applied at V8 or V12, in no-till area with low Mn content in the soil.

Phosphorylation in liquid sulfur dioxide under prebiotically plausible conditions

In nature, organophosphates provide key functions such as information storage and transport, structural tasks, and energy transfer. Since condensations are unfavourable in water and nucleophilic attack at phosphate is kinetically inhibited, various abiogenesis hypotheses for the formation of organophosphate are discussed. Recently, the application of phosphites as phosphorylation agent showed promising results. However, elevated temperatures and additional reaction steps are required to obtain organophosphates. Here we show that in liquid sulfur dioxide, which acts as solvent and oxidant, efficient organophosphate formation is enabled. Phosphorous acid yields up to 32.6% 5′ nucleoside monophosphate, 3.6% 5′ nucleoside diphosphate, and the formation of nucleoside triphosphates and dinucleotides in a single reaction step at room temperature. In addition to the phosphorylation of organic compounds, we observed diserine formation. Thus, we suggest volcanic environments as reaction sites for biopolymer formation on Early Earth. Because of the simple recyclability of sulfur dioxide, the reaction is also interesting for synthesis chemistry.

Phosphite treatment can improve root biomass and nutrition use efficiency in wheat.

Phosphite represents a reduced form of phosphate that belongs to a class of crop growth-promoting chemicals termed biostimulants. Previous research has shown that phosphite application can enhance root growth, but its underlying mechanism, especially during environmental stresses, remains elusive. To uncover this, we undertook a series of morphological and physiological analyses under nutrient, water and heat stresses following a foliar application in wheat. Non-invasive 3D imaging of root system architecture directly in soil using X-ray Computed Tomography revealed that phosphite treatment improves root architectural traits and increased root biomass. Biochemical and physiological assays identified that phosphite treatment significantly increases Nitrate Reductase (NR) activity, leaf photosynthesis and stomatal conductance, suggesting improved Nitrogen and Carbon assimilation, respectively. These differences were more pronounced under heat or drought treatment (photosynthesis and photosystem II stability) and nutrient deficiency (root traits and NR). Overall our results suggest that phosphite treatment improves the ability of plants to tolerate abiotic stresses through improved Nitrogen and Carbon assimilation, combined with improved root growth which may improve biomass and yield.

Foliar application of phosphite reduces grain weight of soybean facing postflowering phosphorus deficiency

AbstractBackground and aimWe aimed to contribute with the foundation to adopt foliar P fertilization on soybean.MethodsTreatments were a combination of contrasting postflowering root P supply versus foliar application of phosphate (Pi) or phosphite (Phi).ResultsPi improved grain yield of P‐limited plants, while Phi was detrimental because of negative effects on grain weight.ConclusionsThus, cautions should be taken with foliar application of Phi during the generative phase of soybean under low‐P stress, as Phi impairs grain filling process.

Applications of Calcium Boron or Potassium Phosphite Combined with Different Fruit Thinning Styles to Enhance Fruit Quality of Barhee date palm

Applications of Calcium Boron or Potassium Phosphite Combined with Different Fruit Thinning Styles to Enhance Fruit Quality of Barhee date palm

Endophytic Yeasts for the Biocontrol of Phlyctema vagabunda in Apples

Bull’s-eye rot, produced by Phlyctema vagabunda, is an important postharvest disease in apples. Current measures to control infection include synthetic fungicides, in addition to the application of copper hydroxide and potassium phosphite. However, growing public concern regarding fungicide residues in food has generated interest in developing non-chemical alternative control methods; biological control is one of the most promising alternatives. In this research, native endophytic yeasts were isolated and evaluated for the biocontrol of P. vagabunda in apples. The mechanisms of action involved were also determined. Our research found 2 isolates, Vishniacozyma victoriae EPL4.5 and EPL29.5, which exhibited biocontrol activity against P. vagabunda at 20 °C in apples, the incidence of bull’s-eye rot was reduced by 39% and 61%, respectively, and the severity of the disease was decreased by 67% and 70%, respectively, when apples were inoculated with these yeasts 24 h before applying the pathogen. The main mechanisms that could be involved in the observed biocontrol activity are the ability to form biofilms and the production of volatile organic compounds.

Response of ‘Prata anã’ banana to post-harvest phosphite application

Abstract The objective of the present study was to determine the best phosphite source and concentration to control anthracnose and its effects on the physical and chemical characteristics of ‘Prata-anã’ banana. Bouquets of banana fruits were immersed in solutions containing different formulations of copper phosphite FCu1 (4% Cu + 20% P2O5), FCu2 (4% Cu + 22% P2O5) at concentrations of 0.5; 1.0, 1.5- and 2.0-mL L-1 and potassium phosphite FK (42% P2O5 + 27.7% K2O) at concentrations of 0.5; 1.0, 1.5 and 2.0 mg L-1. Controls consisted of the application of pure water and Imazalil application (0.5 mL. L-1). Subsequently, anthracnose incidence and severity were evaluated every three days. The physical and chemical characteristics of fruits were evaluated at the end of the anthracnose intensity evaluation. The experimental design used was completely randomized. The results showed that the different phosphite sources FCu1, FCu2 and FK at the concentrations tested were not effective in controlling anthracnose. The physical and chemical characteristics of fruits were influenced by the different phosphite sources and concentrations applied. Fresh fruit mass loss is proportional to the applied phosphite concentration.

Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus.

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases. Applying a new method of search based on an explicit, rigorous, and transparent methodology. For this purpose, a systematic literature review was conducted using the databases available for academic research. The main plant defence mechanisms reported in the cited papers are the hypersensitivity response, cell wall reinforcement, production of pathogenesis-related proteins, and expression of defence-related genes. Moreover, the main strategies to manage Phytophthora root rot are organic compounds in the soil and biological control with fungi and bacteria. In addition, inhibition of Phytophthora gummosis or canker by applying new oomycota fungicides and reducing the incidence of brown fruit rot through the application of potassium phosphite have also been reported. Moreover, modern plant biotechnology techniques can help to accelerate the selection of resistant rootstocks in breeding programs, as controlled crossings for the generation of hybrids, somatic hybridisation, transgenic citrus plants, mapped genomic regions of Quantitative Trait Loci (QTLs), candidate genes, metabolic markers and comparative transcriptomic. These innovative techniques represent a suitable tool to breed new Phytophthora resistant rootstocks, which is widely recognised as the best strategy to face gummosis or foot rot, fibrous root rot and ultimately minimise the expensive use of pesticides in crop protection.

Use of elicitors and fungicides for the postharvest management of Monilinia fructicola in peach

Abstract The aim of this research was to study the effect of two factors: elicitors and fungicide doses. The experiment was conducted in 2017 and 2018. The treatments were applied in four randomized complete blocks with six peach trees as the experimental unit. The effectiveness of treatments was evaluated after harvest so that fruits were inoculated with Monilinia fructicola and lesion diameter measurements were performed to evaluate the area under the disease progress curve (AUDPC) and determine the rate of increase. The content of total phenols and the activity of peroxidase, polyphenoloxidase, catalase and phenylalanine ammonia-lyase enzymes were evaluated. The results showed that applications of potassium phosphite combined with full fungicide doses reduced AUDPC of Monilinia fructicola by 47% compared with the control (no elicitor, no fungicide). The content of phenols and the enzymatic activity increased with the application of elicitors. Pre-harvest application of elicitors is a viable option for the postharvest management of Monilinia fructicola.

Corrigendum to: Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus.

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases. Applying a new method of search based on an explicit, rigorous, and transparent methodology. For this purpose, a systematic literature review was conducted using the databases available for academic research. The main plant defence mechanisms reported in the cited papers are the hypersensitivity response, cell wall reinforcement, production of pathogenesis-related proteins, and expression of defence-related genes. Moreover, the main strategies to manage Phytophthora root rot are organic compounds in the soil and biological control with fungi and bacteria. In addition, inhibition of Phytophthora gummosis or canker by applying new oomycota fungicides and reducing the incidence of brown fruit rot through the application of potassium phosphite have also been reported. Moreover, modern plant biotechnology techniques can help to accelerate the selection of resistant rootstocks in breeding programs, as controlled crossings for the generation of hybrids, somatic hybridisation, transgenic citrus plants, mapped genomic regions of Quantitative Trait Loci (QTLs), candidate genes, metabolic markers and comparative transcriptomic. These innovative techniques represent a suitable tool to breed new Phytophthora resistant rootstocks, which is widely recognised as the best strategy to face gummosis or foot rot, fibrous root rot and ultimately minimise the expensive use of pesticides in crop protection.

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.

Foliar Application of Zn Phosphite and Zn EDTA in Soybean (Glycine max (L.) Merrill): In Vivo Investigations of Transport, Chemical Speciation, and Leaf Surface Changes

Due to a zinc-deficient diet, about 800,000 children die each year worldwide. This aspect is amended by exploiting foliar fertilization, a useful alternative to improve crop yield and nutritional quality of food crops. The aim of this study was then to investigate the leaf uptake and transport of zinc by soybean (Glycine max (L) Merrill). Plant leaves were treated with Zn phosphite and Zn ethylenediamine tetra-acetic acid (EDTA) commercial formulations. X-ray spectroscopy (XRF and XANES) was exploited to trace nutrient movement in the petiolule and scanning electron microscopy (SEM) to evaluate the influence of leaf surface treatments. No radiation damage, in terms of elemental redistribution, was observed during the XRF and XANES measurements. As an alternative to radioisotopes, XRF allowed to detect the movement of Zn from both sources in the plant petiolule. Both fertilizers disintegrated leaf epicuticular wax crystals, yet accumulation of sediments in the vicinity of stomata was noted only for Zn phosphite. Absorption and redistribution of Zn were higher for plants that received Zn phosphite. Zinc supplied as Zn phosphite was transported in a form different from that of the pristine Zn phosphite, whereas Zn supplied as Zn EDTA was transported in its chelated form.

Effects of elevated atmospheric CO2 and temperature on the management of powdery mildew of zucchini

AbstractThe impact of combined environmental factors, such as temperature and CO2, on the control of the powdery mildew of zucchini, caused by Podosphaera xanthii, and of different control measures has been studied on plants grown in phytotrons. Five experimental trials were conducted, and the powdery mildew severity of both treated and untreated zucchini plants was found to be significantly affected by the interaction between temperature (three different regimes: 16–18; 18–22; 22–26°C), CO2 (two concentrations: 400–450 and 800–850 ppm) and the treatments. However, at the end of the trials, the efficacy of all the products was not affected by the different, tested environmental conditions. Sulphur consistently provided the highest disease control (75%–85% efficacy). Among the resistant inducers that were tested, calcium oxide was the most effective, in terms of powdery mildew control under all the conditions tested in phytotrons, reducing disease severity from 46% to 61%. Foliar applications of phosphite (14%–28% efficacy), Ampelomyces quisqualis (12%–23% efficacy) and potassium silicate (13%–24% efficacy) only slightly reduced the disease severity for all the tested temperature regimes and CO2 concentrations, compared to the untreated control. The results obtained under our experimental conditions show that a possible increase in CO2 concentration and temperature, which is expected for the next few years, should not influence the efficacy of the tested resistance inducers or of sulphur against powdery mildew on zucchini. Moreover, the suppressive effect of calcium oxide is in light of its possible use in greenhouses for zucchini powdery mildew control under 400–450 ppm of CO2 and under enriched condition of 800–850 ppm of CO2.

Phosphite Application Alleviates Pythophthora infestans by Modulation of Photosynthetic and Physio-Biochemical Metabolites in Potato Leaves.

Potato late blight (Phytophtora infestans) is among the most severely damaging diseases of potato (Solanum tuberusom L.) worldwide, causing serious damages in potato leaves and tubers. In the present study, the effects of potassium phosphite (KPhi) applications on photosynthetic parameters, enzymatic and non-enzymatic antioxidant properties, hydrogen peroxide (H2O2) and malondialdehyde (MDA), total protein and total carbohydrate of potato leaves challenged with P. infestans pathogen were investigated. Potato leaves were sprayed five times with KPhi (0.5%) during the growing season prior to inoculation with P. infestans. The potato leaves were artificially infected by the LC06-44 pathogen isolate. The leaves were sampled at 0, 24, 48, 72 and 96 h after the infection for evaluations. P. infestans infection reduced chlorophyll (Chl) pigments contents, chlorophyll fluorescence, carotenoid (Car) and anthocyanin contents and increased the accumulation of H2O2 and MDA. Meanwhile, our result showed that KPhi treatment alleviated adverse effect of late blight in potato leaves. KPhi application also increased plant tolerance to the pathogen with improved photosynthetic parameters Chl a, b, total Chl, Car, and anthocyanin compare to controls. Moreover, the increased oxidative enzymes activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APx), and non-enzymatic substances such as phenolics, flavonoids and proline were found in KPhi treated plants, compared to untreated plants after inoculation. In addition, KPhi application followed by P. infestans infection also decreased the content of H2O2 and MDA, but increased the total protein and total carbohydrate contents in potato leaves. The consequence of current research indicated that KPhi played a vital role in pathogen tolerance, protecting the functions of photosynthetic apparatus by improved oxidative levels and physio-biochemical compounds in potato leaves.

Effect of biocontrol agents and potassium phosphite against Phytophthora crown rot, caused by Phytophthora capsici, on zucchini in a closed soilless system

Five biocontrol agents and potassium phosphite, used at various concentrations and at a different number of applications, have been tested to establish their ability to control Phytophthora capsici on hydroponically grown zucchini plants. In a first set of trials, various experimental biocontrol agents (Trichoderma sp. TW2, a mixture of Pseudomonas FC7B, FC8B, FC9B, Fusarium solani FUS25 and Pseudomonas sp. PB26) and a commercial formulation of Trichoderma gamsii +T. asperellum (Remedier) were applied at the artificial infestation with the pathogen of a peat substrate, 5–7 days before planting the zucchini seedlings, and later at 5-day-intervals. BCAs were compared with a potassium phosphite-based fertiliser. In a second set of trials, the potassium phosphite fertiliser was applied directly to the growing media or via a nutrient solution every 6 days, starting at the infestation with the pathogen and 5–7 days before planting, in order to select the optimal rate, type and number of applications. Potassium phosphite reduced Phytophthora crown rot of zucchini by 62–94%, providing more consistant disease severity reduction than those achieved using the experimental BCAs, alone or in mixture, and the Trichoderma gamsii + T. apserellum formulated mixture (29–47% reduction in disease severity). One application of potassium phosphite, at the highest tested concentration, was less effective than three applications. Potassium phosphite consistently reduced the severity of Phytophthora crown rot under different disease pressure (by 48–79%) when applied via a treated peat growing media or via a nutrient solution with 3–6 applications, thereby offering growers an important opportunity to control P. capsici on soilless grown zucchini.