Protocol for the preparation of TiO2-modified boron-doped diamond photoelectrode via electrophoretic deposition and its photoelectrochemical study.

Electrophoretic deposition is a straightforward method for synthesizing high-quality photoanodes. We present a protocol for synthesizing a TiO2-modified boron-doped diamond photoanode (BDD/TiO2) via electrophoretic deposition, detailing the chemical and electrochemical treatments applied to the bare BDD electrode prior to use. We provide a step-by-step guide for performing photoelectrochemical characterization under both dark and light conditions and describe an optical technique for investigating band-gap energy. For complete details on the use and execution of this protocol, please refer to Quilumbaquin et al.1.

Efficient electrochemical advanced degradation of Red CL and Red WB dyes from the tanning industry using a boron-doped diamond anode.

Electrochemical oxidation (EO), electro-Fenton (EF), and photoelectro-Fenton (PEF) with a BDD anode have been comparatively assessed to remediate solutions of Red CL and/or Red WB azo dyes from real raw water. For the EO process in 50 mM Na2SO4 at pH 3.0, the main oxidant was the heterogeneous •OH generated at the anode, whereas in EF and PEF, the cathodic production of H2O2 and the addition of 0.50 mM Fe2+ catalyst additionally originated homogeneous •OH that enhanced the oxidation of organics. In PEF, the solution was illuminated with a 6 W UVA light. An almost total discoloration was always found operating with a 1:1 mixture of 200 mg L-1 of both dyes in 60 min, whose efficiency increased in the order of EO < EF < PEF. The HPLC analysis of the dye mixture treated by PEF disclosed that its degradation process agreed with its discoloration. A high 74% of COD was reduced due to the oxidative action of hydroxyl radicals and the photolysis of final Fe(III)-carboxylate species with UVA irradiation. The process was accompanied by an energy consumption of 0.76 kWh (g COD)-1, a value similar to the energy consumed by the applied UVA light.

Optoelectronic Response to the Fluor Ion Bond on 4-(4,4,5,5-Tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde.

Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms 1H, carbon 13C and boron 11B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde. Furthermore, this study considers the change in its electronic and spectroscopic properties of this particular ester, when its boron atom is coordinated with a fluoride anion. The calculations were carried out using the LSDA and B3LYP functionals in Gaussian-16, and PBE in CASTEP. The results show that the B3LYP functional gives the best approximation to the experimental data. The formation of a coordinated covalent B-F bond highlights the remarkable sensitivity of the NMR chemical shifts of carbon, oxygen, and boron atoms and their surroundings. Furthermore, this bond also highlights the changes in the electron transitions bands n → π* and π → π* during the absorption and emission of a photon in the UV-vis, and in the stretching bands of the C=C bonds, and bending of BO2 in the infrared spectrum. This study not only contributes to the understanding of the properties of boronate esters but also provides important information on the interactions and responses optoelectronic of the compound when is bonded to a fluorine atom.

Genotoxicity in humans exposed to arsenic, lithium, and boron in drinking water in the Bolivian Andes-A cross sectional study.

Elevated concentrations of arsenic, lithium and boron in drinking water have already been reported in Bolivia. Arsenic is known to cause genotoxicity but that caused by lithium and boron is less well known. The aim of the present cross-sectional study was to evaluate potential genotoxic effects of exposure to arsenic, while considering exposure to lithium and boron and genetic susceptibility. Women (n = 230) were recruited in villages located around Lake Poopó. Exposure to arsenic was determined as the sum of concentrations of arsenic metabolites inorganic arsenic, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine. Exposure to lithium and boron was determined based on their concentrations in urine. Genetic susceptibility was determined by GSTM1 (glutathione S-transferase-mu-1) and GSTT1 (glutathione S-transferase-theta-1) null genotypes and AS3MT (Arsenite Methyltransferase) rs3740393. Genotoxicity was measured in peripheral blood leukocytes using the comet assay. The geometric means of arsenic, lithium, and boron concentrations were 68, 897, and 3972 µg/L, respectively. GSTM1 and GSTT1 null carriers had more DNA strand breaks than gene carriers (p = .008, p = .005). We found no correlation between urinary arsenic and DNA strand breaks (rS = .03, p = .64), and only a weak non-significant positive association in the adjusted multivariate analysis (ß = .09 [-.03; .22], p = .14). Surprisingly, increasing concentrations of lithium in urine were negatively correlated with DNA strand breaks (rS = -.24, p = .0006), and the association persisted in multivariate analysis after adjusting for arsenic (ß = -.22 [-.36; -.08], p = .003). We found no association between boron and DNA strand breaks. The apparent protective effect of lithium merits further investigation.

Recent advances in boron removal in aqueous media. An approach to the adsorption process and process optimization.

The numerous oxidation states of the element boron bring great challenges in containing its contamination in receptor bodies. This scenario increases significantly due to the widespread use of boron compounds in various industries in recent years. For this reason, the removal of this contaminant is receiving worldwide attention. Although adsorption is a promising method in boron removal, finding suitable adsorbents, that is, those with high efficiency, and feasible remains a constant challenge. Hence, this review presents the boron removal methods in comparison to costs of adsorbents, reaction mechanisms, economic viability, continuous bed application, and regeneration capacity. In addition, the approach of multivariate algorithms in the solution of multiobjective problems can enable the optimized conditions of dosage of adsorbents and coagulants, pH, and initial concentration of boron. Therefore, this review sought to comprehensively and critically demonstrate strategic issues that may guide the choice of method and adsorbent or coagulant material in future research for bench and industrial scale boron removal.

Boron-containing coating yields enhanced antimicrobial and mechanical effects on translucent zirconia.

OBJECTIVES: To evaluate the mechanical and antimicrobial properties of boron-containing coating on translucent zirconia (5Y-PSZ). METHODS: 5Y-PSZ discs (Control) were coated with a glaze (Glaze), silver- (AgCoat), or boron-containing (BCoat) glasses. The coatings' antimicrobial potential was characterized using S. mutans biofilms after 48 h via viable colony-forming units (CFU), metabolic activity (CV) assays, and quantification of extracellular polysaccharide matrix (EPS). Biofilm architectures were imaged under scanning electron and confocal laser scanning microscopies (SEM and CLSM). The cytocompatibility was determined at 24 h via WST-1 and LIVE&DEAD assays using periodontal ligament stem cells (PDLSCs). The coatings' effects on properties were characterized by Vickers hardness, biaxial bending tests, and fractography analysis. Statistical analyses were performed via one-way ANOVA, Tukey's tests, Weibull analysis, and Pearson's correlation analysis. RESULTS: BCoat significantly decreased biofilm formation, having the lowest CFU and metabolic activity compared with the other groups. BCoat and AgCoat presented the lowest EPS, followed by Glaze and Control. SEM and CLSM images revealed that the biofilms on BCoat were thin and sparse, with lower biovolume. In contrast, the other groups yielded robust biofilms with higher biovolume. The cytocompatibility was similar in all groups. BCoat, AgCoat, and Glaze also presented similar hardness and were significantly lower than Control. BCoat had the highest flexural strength, characteristic strength and Weibull parameters (σF: 625 MPa; σ0: 620 MPa; m = 11.5), followed by AgCoat (σF: 464 MPa; σ0: 478 MPa; m = 5.3). SIGNIFICANCE: BCoat is a cytocompatible coating with promising antimicrobial properties that can improve the mechanical properties and reliability of 5Y-PSZ.

From nuclear track characterization to machine learning based image classification in neutron autoradiography for boron neutron capture therapy.

Knowledge of the 10B microdistribution is of great relevance in BNCT studies. Since 10B concentration assesment through neutron autoradiography depends on the correct quantification of tracks in a nuclear track detector, image acquisition and processing conditions should be controlled and verified, in order to obtain accurate results to be applied in the frame of BNCT. With this aim, an image verification process was proposed, based on parameters extracted from the quantified nuclear tracks. Track characterization was performed by selecting a set of morphological and pixel-intensity uniformity parameters from the quantified objects (area, diameter, roundness, aspect ratio, heterogeneity and clumpiness). Their distributions were studied, leading to the observation of varying behaviours in images generated by different samples and acquisition conditions. The distributions corresponding to samples coming from the BNC reaction showed similar attributes in each analyzed parameter, proving to be robust to the experimental process, but sensitive to light and focus conditions. Considering those observations, a manual feature extraction was performed as a pre-processing step. A Support Vector Machine (SVM) and a fully dense Neural Network (NN) were optimized, trained, and tested. The final performance metrics were similar for both models: 93%-93% for the SVM, vs 94%-95% for the NN in accuracy and precision respectively. Based on the distribution of the predicted class probabilities, the latter had a better capacity to reject inadequate images, so the NN was selected to perform the image verification step prior to quantification. The trained NN was able to correctly classify the images regardless of their track density. The exhaustive characterization of the nuclear tracks provided new knowledge related to the autoradiographic images generation. The inclusion of machine learning in the analysis workflow proves to optimize the boron determination process and paves the way for further applications in the field of boron imaging.

The synergistic effects of soil-applied boron and foliar-applied silicon on cotton fiber quality and yield.

Studies of boron (B) and silicon (Si) synergy in cotton crops have shown promising results; however, the focus was on the foliar application of B and Si. Nonetheless, B is an element with little mobility in the plant and its best form of application is in the soil. Thus, the objective of this study was to evaluate the synergistic effect of soil applied B and foliar applied sSi on fiber quality and crop yield of cotton. For this purpose, a field experiment was carried out using cotton cultivar FM 985 GLTP. The soil's B in the experimental site is classified as low for cotton cultivation. The experiment was conducted in a randomized complete-block design, in a 3 × 2 factorial scheme, with three doses of B: 0.0 kg ha-1 (deficiency), 2.0 kg ha-1 (recommended dose), and 4.0 kg ha-1 (high dose) in the absence and presence (920 g L-1) of Si, with four replications. One week after the 4th application of Si, B and Si leaf content was determined. At boll opening, crop yield was estimated, and fiber quality analysis was realized. Boron deficiency reduced cotton yield, in 11 and 9%, compared to the application of 2 and 4 kg ha-1 of B, respectively. The presence of Si, however, increased plant yield in 5% in the treatments with 0 and 2 kg ha-1 of B, respectively. Cotton fiber length and elongation were not influenced by the B doses and Si presence. Fiber breaking strength was increased in 5% by the presence of Si and was not influenced by B deficiency. Micronaire was 8% smaller in the treatment with 0 kg ha-1 of B and 6% smaller in the absence of Si. Short fiber index was 4% greater in the plants of the treatment with 0 kg ha-1 of B. The results of this study reports that the complementation with Si via foliar application increases fiber quality by enhance breaking strength and micronaire. In conclusion, the interaction between soil-applied B and foliar-applied Si is beneficial for cotton cultivation, resulting in high cotton yield with better fiber quality.

Physiological and metabolic changes in response to Boron levels are mediated by ethylene affecting tomato fruit yield.

Boron (B) is an essential nutrient for the plant, and its stress (both deficiency and toxicity) are major problems that affect crop production. Ethylene metabolism (both signaling and production) is important to plants' differently responding to nutrient availability. To better understand the connections between B and ethylene, here we investigate the function of ethylene in the responses of tomato (Solanum lycopersicum) plants to B stress (deficiency, 0 µM and toxicity, 640 µM), using ethylene related mutants, namely nonripening (nor), ripening-inhibitor (rin), never ripe (Nr), and epinastic (Epi). Our results show that B stress does not necessarily inhibit plant growth, but both B stress and ethylene signaling severely affected physiological parameters, such as photosynthesis, stomatal conductance, and chlorophyll a fluorescence. Under B toxicity, visible symptoms of toxicity appeared in the roots and margins of the older leaves through necrosis, caused by the accumulation of B which stimulated ethylene biosynthesis in the shoots. Both nor and rin (ethylene signaling) mutants presented similar responses, being these genotypes more sensitive and displaying several morphophysiological alterations, including fruit productivity reductions, in response to the B toxicity conditions. Therefore, our results suggest that physiological and metabolic changes in response to B fluctuations are likely mediated by ethylene signaling.

Borophosphate glasses as active agents for antimicrobial hydrogels.

Herein we report the synthesis of transition-metal-free potassium borophosphate glasses and their application as bactericidal and bacteriostatic material. The antimicrobial activity was achieved through a simple change in the molar ratio of boron and phosphorus atoms, making borophosphate glass soluble in water. The glasses were analyzed by X-ray powder diffraction, Raman spectroscopy, laser-induced breakdown spectroscopy, and water absorption. The addition of a boron compound is required to obtain potassium-based phosphate glasses. Moreover, the change in the phosphorus and boron molar ratio (P/B), 2, 1 or 0.5 affects the glass solubilization in water, which increases with the phosphorus content. The glass materials were submitted to tests of biological activity against the bacteria Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. These water-soluble borophosphate glasses were employed in the development of hydrogel formulations using Carbopol®. Phosphorous-rich samples at a concentration of 15 % (w/w) in hydrogel showed better antimicrobial activity against S. aureus and E. coli, when compared to other samples, including commercial alcohol hand sanitizer gel, with an average size of the inhibition halo of 24.02±1.43 and 19.24±1.63mm, respectively.

Measurement of an evaporation coefficient in tissue sections as a correction factor for 10B determination.

Boron neutron capture therapy (BNCT) is a cancer treatment option that combines preferential uptake of a boron compound in tumors and irradiation with thermal neutrons. For treatment planning, the boron concentration in different tissues must be considered. Neutron autoradiography using nuclear track detectors (NTD) can be applied to study both the concentration and microdistribution of boron in tissue samples. Histological sections are obtained from frozen tissue by cryosectioning. When the samples reach room temperature, they undergo an evaporation process, which leads to an increase in the boron concentration. To take this effect into account, certain correction factors (evaporation coefficients, CEv) must be applied. With this aim, a protocol was established to register and analyze mass variation of tissue sections, measured with a semimicro scale. Values of ambient temperature, pressure, and humidity were simultaneously recorded. Reproducible results of evaporation curves and CEv values were obtained for different tissue samples, which allowed the systematization of the procedure. This study could contribute to a more precise determination of boron concentration in tissue samples through the neutron autoradiography technique, which is of great relevance to make dosimetric calculations in BNCT.

Enhancement in the Therapeutic Efficacy of In Vivo BNCT Mediated by GB-10 with Electroporation in a Model of Oral Cancer.

Boron neutron capture therapy (BNCT) combines preferential tumor uptake of 10B compounds and neutron irradiation. Electroporation induces an increase in the permeability of the cell membrane. We previously demonstrated the optimization of boron biodistribution and microdistribution employing electroporation (EP) and decahydrodecaborate (GB-10) as the boron carrier in a hamster cheek pouch oral cancer model. The aim of the present study was to evaluate if EP could improve tumor control without enhancing the radiotoxicity of BNCT in vivo mediated by GB-10 with EP 10 min after GB-10 administration. Following cancerization, tumor-bearing hamster cheek pouches were treated with GB-10/BNCT or GB-10/BNCT + EP. Irradiations were carried out at the RA-3 Reactor. The tumor response and degree of mucositis in precancerous tissue surrounding tumors were evaluated for one month post-BNCT. The overall tumor response (partial remission (PR) + complete remission (CR)) increased significantly for protocol GB-10/BNCT + EP (92%) vs. GB-10/BNCT (48%). A statistically significant increase in the CR was observed for protocol GB-10/BNCT + EP (46%) vs. GB-10/BNCT (6%). For both protocols, the radiotoxicity (mucositis) was reversible and slight/moderate. Based on these results, we concluded that electroporation improved the therapeutic efficacy of GB-10/BNCT in vivo in the hamster cheek pouch oral cancer model without increasing the radiotoxicity.

Simultaneous voltammetric determination of 7-methyl-guanine and 5-methyl-cytosine using a cathodically pre-treated boron-doped diamond electrode.

Given the importance of identifying the presence of biomarkers of human diseases in DNA samples, the main objective of this work was to investigate, for the first time, the electro-catalytic oxidation of 7-methyl-guanine (7-mGua) and 5-methyl-cytosine (5-mCyt) on a boron doped diamond electrode pre-treated cathodically (red-BDDE), using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The anodic peak potentials of 7-mGua and 5-mCyt by DPV were at E = 1.04 V and E = 1.37 V at pH = 4.5, indicating excellent peak separation of approximately 330 mV between species. Using DPV, experimental conditions such as supporting electrolyte, pH and influence of interferents were also investigated to develop a sensitive and selective method for individual and simultaneous quantification of these biomarkers. The analytical curves for the simultaneous quantification of 7-mGua and 5-mCyt in the acid medium (pH = 4.5) were: concentration range of 0.50-5.00 µmol L-1 (r = 0.999), detection limit of 0.27 µmol L-1 for 7-mGua; from 3.00 to 25.00 µmol L-1 (r = 0.998), with a detection limit of 1.69 µmol L-1 for 5-mCyt. A new DP voltammetric method for the simultaneous detection and quantification of biomarkers 7-mGua and 5-mCyt using a red-BDDE is proposed.

A Potential Boron Neutron Capture Therapy Agent Selectively Suppresses High-Grade Glioma: In Vitro and in Vivo Exploration.

Glioblastoma (GBM), as the most central nervous system (CNS) intractable disease, has spoiled millions of lives due to its high mortality. Even though several efforts have been made, the existing treatments have had limited success. In this sense, we studied a lead compound, the boron-rich selective epidermal growth factor receptor (EGFR)-inhibitor hybrid 1, as a potential drug for GBM treatment. For this end, we analyzed the in vitro activity of hybrid 1 in a glioma/primary astrocytes coculture, studying cellular death types triggered by treatment with this compound and its cellular localizations. Additionally, hybrid 1 concentrated boron in glioma cells selectively and more effectively than the boron neutron capture therapy (BNCT)-clinical agent 10B-l-boronophenylalanine and thus displayed a better in vitro-BNCT effect. This encouraged us to analyze hybrid 1 in vivo. Therefore, immunosuppressed mice bearing U87 MG human GBM were treated with both 1 and 1 encapsulated in a modified liposome (recognized by brain-blood barrier peptide transporters), and we observed a potent in vivo per se antitumor activity (tumor size decrease and animal survival increase). These data demonstrate that 1 could be a promising new targeted therapy for GBM.

Prescient diagnostic analysis for boron nutritional status in soy crops.

Boron is the most limiting micronutrient for soybean yield; therefore, accurate identification of its nutritional status is important for adequate fertilization management and maximize soybean yield potential. Currently, tools for nutritional status interpretation of B, such as the CND and DRIS are used; however, their efficacy is not considered to identify the true nutritional status of B. In this research, we investigated the efficacy of these methods to identify the nutritional status of B in 140 commercial soybean crops to obtain nutritional standards for the DRIS and CND methods. In addition, an experiment of B dose calibration (0, 300, 600, 1200 and 1800 g ha-1) was installed to assess the quality of nutritional diagnoses using the PDA. The experimental approach tested the limits of 0.25, 0.50, and 1.00 for the NRr and values of 1%, 5%, or 10% for YR. The DRIS method was more effective, and, on average, its variations increased yield by 27% compared to CND, with the best performance of DRIS when NRr = 1.00 was adopted with 10% for YR. This study highlights the need for reliable and accurate diagnostic methods with global implications for crop sustainability by improving the efficacy of B fertilization programs and crop yield.

Changes in phytochemical composition of Merlot grape and wine induced by the direct application of boron.

In this study the effect of the direct application of different concentrations of boron in grape bunches on the phytochemical composition of grapes and wine was evaluated. The experiment was carried out by direct application to the grape bunch of different concentrations (0, 1.0, 2.0, 4.0 and 8.0 g/L) of boron solution, in two consecutive vintages, 2018 and 2019. The wines were elaborated by the same microvinification method. Histological analyzes by optical microscopy and phenolic profile by HPLC-DAD were performed on the grapes. The wines were analyzed by HPLC-DAD and ICP-MS for phenolic profile and elemental composition, respectively. Histological analyzes of the grape skin showed an increase in the presence of polyphenols in the cellular tissue of grapes treated with different concentrations of boron when compared to the control samples in both vintages. The addition of boron influenced the phenolic profile of the grapes, resulting in an increase in the content of anthocyanins and flavanols. Regarding to wines, the treatment of grapes by direct application of boron significantly influenced the chemical composition of wines. In 2018, the application of 2 g/L of boron showed a significant increase in the concentration of malvidin and delphinidin in wines. The application of 1 g/L showed the highest concentration of malvidin, delphinidin and peonidin in the 2019 vintage. The boron content increased in the wine samples according to the boron concentrations applied to the grape. Thus, it is possible to produce chemically distinct wines with the direct application of boron to the grapes.

Boron-Containing Compounds for Prevention, Diagnosis, and Treatment of Human Metabolic Disorders.

The application of natural and synthetic boron-containing compounds (BCC) in biomedical field is expanding. BCC have effects in the metabolism of living organisms. Some boron-enriched supplements are marketed as they exert effects in the bone and skeletal muscle; but also, BCC are being reported as acting on the enzymes and transporters of membrane suggesting they could modify the carbohydrate metabolism linked to some pathologies of high global burden, as an example is diabetes mellitus. Also, some recent findings are showing effects of BCC on lipid metabolism. In this review, information regarding the effects and interaction of these compounds was compiled, as well as the potential application for treating human metabolic disorders is suggested.

Moderate Toxicity of Potential Boron-containing Therapeutic, Dipotassium-trioxohydroxytetrafl uorotriborate - K2 (B3 O3 F4 OH) in Rats and Mice

Abstract Biological activity of boron-containing compounds (BCCs) has been well-known. Growing interest and numerous applications for BCCs have been reported. Boron and boron-containing acids show low acute toxicity in mammals but data on halogenated boroxine (HB) - dipotassium-trioxohydroxytetrafluorotriborate, K2(B3O3F4OH) acute toxicity have not been reported before. This compound, characterized as a potential therapeutic for skin changes, exhibits no observable genotoxicity in doses lower that 0.1 mg/ml in vitro and 55 mg/kg in vivo. It has also been confirmed as an antitumour agent both in vitro and in vivo as well as an inhibitor of enzymes involved in antioxidant mechanisms. The aim of this study was to assess the acute toxicity of HB and to determine the maximum tolerated dose as well as a dose free of any signs of toxicity in different test organisms. Acute toxicity of HB was tested in Sprague-Dawley and Wistar rats and BALB/c mice after single parenteral application of different doses. We determined doses free of any sign of toxicity and LD50 after single dose administration. LD50 of HB ranges from 63 to 75 mg/kg in different test models, meaning that HB shows moderate toxicity

Exploring the effect of zinc and boron application on oil contents, protein contents, growth and yield of sunflower / Explorando o efeito da aplicação de zinco e boro no teor de óleo, teor de proteína, crescimento e rendimento de girassol

Sunflower is sensitive to boron (B) and zinc (Zn) deficiency when grown on deficient soil, A field experiment was conducted to determine the main and interactive effects of soil applied Zn and B on total production of sunflower at Agronomic Research Area, University of Agriculture, Faisalabad. Experiment was laid out in randomized complete block design (RCBI) with factorial arrangement using three replications with net plot size of 6 m x 4.5 m. The soil application of variable levels of Zn (0, 10, 20 and 30 kg ha-1) and B (0, 1, 2 and 3 kg ha-1) in the form of zinc sulphate and boric acid, respectively were applied at time of sowing. All other agronomic and plant protection practices were kept uniform. The data regarding growth, yield and quality parameters were noted by using standard procedures. Results showed that Zn @ 20 kg ha-1 and B @ 3 kg ha-1 significantly increased the number of plants per plot at harvest, stem diameter, head diameter, number of achenes per head, 1000-achene weight, biological yield and days to maturity, achene yield kg per, harvest index, leaf concentrations or Zn at heading stage, leaf concentrations of B at heading stage (ppm), achene oil content (%), achene protein contents as compared to control. This study concluded that higher growth and yield of sunflower can be achieved by application of Zn at 20 kg ha-1 and B at 3 kg ha-1 under Faisalabad conditions.(AU)

O girassol é sensível à deficiência de boro (B) e zinco (Zn) quando cultivado em solo deficiente. Um experimento de campo foi conduzido para determinar os efeitos principais DA interação Zn e B aplicados no solo na produção total de girassol na Área de Pesquisa Agronômica, Universidade de Agricultura, Faisalabad. O experimento foi realizado em delineamento de blocos completos casualizados (RCBI), com arranjo fatorial, utilizando três repetições e parcelas de 6 m x 4,5 m. A aplicação no solo de níveis variáveis de Zn (0, 10, 20 e 30 kg ha-1) e B (0, 1, 2 e 3 kg ha-1) foi aplicada em época da semeadura na forma de sulfato de zinco e ácido bórico, respectivamente. As práticas agronómicas e de proteção fitossanitária foram mantidas uniformes. A aplicação de 20 kg ha-1 de Zn e 3,0 kg ha-1 de B aumentaram o número de plantas por parcela na colheita, diâmetro do caule, diâmetro da cabeça, número de aquênios por cabeça, peso de 1000 aquênios, rendimento biológico e dias até a maturidade, rendimento de aquênios, índice de colheita, concentrações foliares de Zn no estágio de espigamento, concentrações foliares de B no estágio de espigamento, teor de óleo de aquênio, aquênio conteúdo de proteína em comparação com o controle. O maior crescimento e rendimento do girassol podem ser alcançados pela aplicação de Zn a 20 kg ha-1 e B a 3 kg ha-1 nas condições de Faisalabad.(AU)

Does the application of boron in different stages of soy crop affect its productivity? / A aplicação de boro em diferentes estádios da cultura da soja afetam sua produtividade?

Soybean is one of the most demanding annual crops in boron (B), however, there is a divergence regarding the best phenological stage to carry out this application via foliar. Therefore, the objective of the present work was to evaluate the influence of different times of foliar application of B, with and without splitting, on flowering, productivity, and components of soybean production. For this, an experiment was carried out in the field, the experimental design used was in randomized blocks, with seven times of foliar applications of B (control, 100% 15 V4, 100% R1, 100% R3, 50% V4 + 50% R1, 50% V4 + 50% R3 and 50% R1 + 50% R3) and four replications, totaling 28 experimental plots. The number of flowers, number of beginning pod, B content in plants, weight of 1000 grains (g) and productivity were analyzed. The highest B content was observed with applications in the V4 (50%) + R1 (50%) and V4 (50%) + R3 (50%) stages, that is, part in the vegetative stage and part in the reproductive stage. The application of B did not result in a significant difference in relation to the number of inflorescences per plant. There was no significant effect of the times of foliar application of B for the variable of number of pods per plant, number of inflorescences and productivity. For weight of 1000 grains (g) higher values were found in V4, R1 and R3 and in the control. Therefore, the foliar application of boron in the stages V4 (50%) + R1(50%) and V4(50%) + R3 (50%) increased the levels of B in the plant, while in R1+R3 it provided the highest number of beginning pods. However, there was no effect of boron application for grain yield regardless of the time of application.(AU)

A soja é uma das culturas anuais mais exigentes em boro (B), no entanto, existe uma divergência em relação sobre qual melhor estádio fenológico para efetuar essa aplicação via foliar. Logo, o objetivo do presente trabalho foi avaliar a influência de diferentes épocas de aplicação foliar de B, com e sem parcelamento no florescimento, produtividade e componentes da produção da soja. Para tal, foi realizado um experimento em campo, o delineamento experimental utilizado foi em blocos ao acaso, com sete épocas de aplicações foliares de B (testemunha, 100% 15 V4, 100% R1, 100% R3, 50% V4 + 50% R1, 50% V4 + 50% R3 e 50% R1 + 50% R3) e quatro repetições, totalizando 28 parcelas experimentais. Foram analisados o número de flores, número de canivete, teor de B nas plantas, peso de 1000 grãos (g) e a produtividade. O maior teor B foi observado com aplicações nos estádios V4 (50%) + R1 (50%) e V4 (50%) + R3 (50%) isto é, parte no estádio vegetativo e parte no estádio reprodutivo. A aplicação de B não resultou em diferença significativa em relação ao número de inflorescências por planta. Não houve efeito significativo das épocas de aplicação foliar de B para a variável de número de vagens por planta, número de inflorescências e produtividade. Para peso de 1000 grãos(g)foram encontrados maiores valores em V4, R1 e R3 e na testemunha. Portanto, a aplicação foliar de boro nos estádios V4 (50%) + R1 (50%) e V4 (50%) + R3 (50%) aumentou os níveis de B na planta, enquanto em R1+R3 proporcionou o maior número de canivetes. No entanto, não houve efeito da aplicação de boro para a produtividade de grãos independente da época de aplicação.(AU)