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Copyright of Revista Agrotecnologia is the property of Universidade Estadual de Goias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The objective of this work was to evaluate the agronomic and economic efficiency of phonolite rock (K2) and alkaline potassium-silicate rock (K3), ground and applied by surface broadcasting, as K sources for the soybean (Glycine max), corn (Zea mays), common bean (Phaseolus vulgaris), and upland rice (Oryza sativa) crops. Four experiments – one with each crop – were conducted in two crop years in a Typic Haplorthox in a randomized complete block design with four replicates. The treatments consisted of three sources (the KCl standard source, K2, and K3) and four rates (0, 0.5, 1.0, and 2.0 times the recommended for each crop) of K. The three sources increased similarly the leaf K concentration of soybean, corn, and common bean but had no effect on that of upland rice. The grain yield of all crops increased with the application of K2 and K3, as observed for KCl. The efficiency of the alternative K sources varies depending on the rate and crop. The K3 source is viable to be applied by broadcasting at the recommended K rate for all studied crops, while K2 is suitable only for soybean, corn, and common bean.

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Silicon has been used in several ways to improve plant growth and development, however, there are few experimental results, especially for tropical grasses. Thus, the objective of this work was to evaluate the effects of applying calcium and magnesium silicate on the growth, structure, and herbage mass of Mombasa grass. A completely randomized design was used in a 3 x 3 factorial arrangement with 4 replications and 2 duplicates for replications. The experimental treatments corresponded to two doses of silicon (1,000 and 2,000 kg/ha) and control (0 kg/ha) over 3 growth cycles. The variables evaluated were plant height, number of tillers, specific leaf area, herbage mass, leaf mass, stem mass, the mass of dead material, and root mass. The application of silicate was not able to modify the variables studied. Considering the soil studied, the application of silicate is not recommended to increase the productivity of Mombasa grass, but similar longer-term studies are needed on soils with low Ca and Mg levels.

Abstract The objective of this work was to evaluate the efficiency and the residual effects of both molten and ground alkaline potassium-silicate rocks (K1) and of ground phonolite rock (K2), as sources of potassium, compared with the traditional source (KCl), in grain crop successions. Two experiments – one with the succession soybean-wheat-corn and the other with the succession corn-millet-soybean – were conducted on a Typic Haplorthox in a randomized complete block design with four replicates. The treatments consisted of three sources (KCl, K1, and K2) and four rates of K (corresponding to 0, 0.5, 1.0, and 2.0 times the recommended rates for soybean and corn). The used sources did not affect leaf K concentration in soybean, but KCl and K2 similarly increased leaf K concentration in corn. Regardless of the source, K application increased the yield of all crops. The K1 and K2 sources present agronomic efficiencies equivalent to that of KCl. K1 and K2 show a more pronounced residual effect than KCl, especially on crops grown approximately one year after their application and under K rates above those recommended for the crops.

Basically, radiation can cause two effects on materials: ionization and non-ionization. This work presented the theory involved in defects caused by non-ionization, known as NIEL, with a focus on silicon materials. When energy is transferred directly to the atoms in the crystalline lattice, it can either be dissipated in the form of vibrations or be large enough to pull atoms out of that lattice. This weakens the lattice, causing measurement errors that can lead to permanent damage. This study is extremely important because silicon materials are used in radiation detectors. These detectors cannot return false measurements, especially in dangerous situations, such as in nuclear reactor monitoring. After presenting the theory involved, examples are shown. Failures of up to 30% were found by the researchers.

ABSTRACT The soils of the Brazilian Savanna are generally acidic and have low availability of nutrients, so the use of alternative inputs to improve their fertility should be investigated. The objectives of this study were to evaluate the potential of biochars from rice husk (BHR) and from bovine manure (BCM) in increasing phosphorus availability and their effects on soil chemical properties and in common beans plants. The experiments were carried out in a completely randomized design, in a 4x2+3 factorial scheme with four replicates. The treatments were four biochar doses (1, 2, 3 and 4% m/v), two biochars (BRH and BCM) and three additional treatments (C1, no liming and no fertilization; C2, addition of Ca and Mg carbonate and NPK fertilizers and; C3, addition of Ca and Mg silicate and NK fertilizers). In the highest doses of BRH there was an increase of 2.7, 5.3 and 2.5 times in the P content extracted by Mehlich 1 and quantified by colorimentria, by Mehlich 1 and quantified by spectroscopy and by ion exchange resin and quantified by spectroscopy, respectively. For the highest doses of BCM, the increases in P content were 51.3, 289.2 and 88.4 times greater than in C1, respectively, according to the methods described for BRH. The biochars increased soil pH, CEC, nutrient content and the growth of bean plants compared to C1, especially BCM. However, the production of dry matter was significantly lower than that obtained in C2.

The application of silicon (Si) to the soil can increase the grain yield of the soybean crop by improving the nitrogen biological fixation, due to its beneficial effect on the Bradyrhizobium-soybean symbiosis. This study aimed to investigate the effect of fertilization with calcium and magnesium silicate on plant growth, root nodulation and nitrogen (N) uptake, in two soybean cultivars [BRS 1074 IPRO (transgenic) and BRS-MG 800A (conventional)], under greenhouse conditions. The application of silicate significantly increased the number of root nodules only for the BRS-MG 800A, while the positive effects of the silicate addition on nodule size, chlorophyll level and leaf N concentration were observed in both cultivars. The soybean cultivars show distinct responses to the silicate application, with respect to growth and dry matter yield, being the BRS 1074 IPRO more responsive than the BRS-MG 800A. Therefore, Si may induce the formation of root nodules in soybean plants and lead to significant increases in the nitrogen biological fixation and plant growth. These results highlight that Si is not only involved in the improvement of plant growth, but it can be also considered a crucial element to improve the symbiotic performance of soybean plants. However, the physiological basis of how and where silicate exerts its influence on nodulation and nitrogen biological fixation still remains unknown.

The objective of the research was to evaluate the residual effect of the seeds treatment with fungicide and silicate fertilizer in the control of brown spot in the vegetative stage of the barley plant. The experiment was a two-way factorial with four seed treatments (ST): control (distilled water), fungicide (triadimenol), silicate fertilizer and the fungicide + silicate fertilizer and three periods of 30, 45 and 60 days after emergence (DAE). Barley plants were inoculated with a spore suspension of Bipolaris sorokiniana. The disease severity assessment over time was used to calculate the area under the brown spot progress curve (AUCPBS). At 30 DAE, fungicide treatment was the most efficient with reduction of 64% in the AUCPBS, followed by silicate fertilizer with 56%. The mixture also reduced AUCPBS, but with lower efficiency than isolated products. [ABSTRACT FROM AUTHOR]

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aluminum foils with a thickness of less than 200 μm are used in numerous applications, such as the manufacture of different products, disposable packaging, radiator fins and blisters. These applications require both good corrosion resistance and mechanical strength. Iron present in 1xxx and 8xxx aluminium alloys forms two main secondary phases: Al3Fe and α-AlFeSi, the last one as dispersoids, altering the kinetics of recrystallization and therefore giving rise to excellent strength and elongations after annealing. Silicon and iron form phases such asO-Al13 Fe4 (monoclinic), Al6Fe (orthorhombic), Al12Fe3Si and Al3Fe, which are controlled during solidification to improve mechanical properties. Manganese present in 3xxx alloys may form two main phases Al6 (Mn, Fe) and α-Al12(Fe, Mn)2Si, but Al12(Fe, Mn)3Si may also be present when silicon is added so many properties are strongly dependent on both type and particles shapes, Thus, microstructure must be well controlled in the solidification and subsequent processes. [ABSTRACT FROM AUTHOR]

Copyright of Engenharia na Agricultura is the property of Engenharia na Agricultura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peach brown rot, caused by the Monilinia fructicola fungus, is the main disease affecting peach crops, and it is mainly controlled via frequent fungicide applications. This study aimed at searching for alternatives to the intensive use of chemicals, evaluating silicon doses to control pre and postharvest peach brown rot and their influence on maturation parameters and fruit quality. Treatments consisted of control (water) and sodium metasilicate doses (2 g L-1, 4 g L-1, 6 g L-1, 8 g L-1 and 10 g L-1 of water). The following assessments were made: spore germination and in vitro mycelial growth, brown rot incidence, soluble solids, titratable acidity, flesh firmness, total polyphenol content and fruit ethylene production and respiration rate. The 2 g L-1 dose reduced spore germination by 95 %. Doses of 6 g L-1 and 8 g L-1 satisfactorily reduced the disease incidence in the field, with 77 % and 89.2 % control, respectively. Sodium metasilicate resulted in the maintenance of great fruit firmness, reduced respiration and ethylene production and increased total polyphenol synthesis, but it did not influence the titratable acidity or soluble solids. Applying 6 g L-1 may potentially control pre and postharvest peach brown rot, besides increasing the total polyphenol synthesis and maintaining a higher flesh firmness.

Abstract Silicon is the second most abundant element on Earth, and the third most abundant trace element in human body. It is present in water, plant and animal sources. On the skin, it is suggested that silicon is important for optimal collagen synthesis and activation of hydroxylating enzymes, improving skin strength and elasticity. Regarding hair benefits, it was suggested that a higher silicon content in the hair results in a lower rate of hair loss and increased brightness. For these beneficial effects, there is growing interest in scientific studies evaluating the efficacy and safety of using dietary supplements containing silicon. Its use aims at increasing blood levels of this element and improving the skin and its annexes appearance. There are different forms of silicon supplements available and the most important consideration to be made in order to select the best option is related to safety and bioavailability. Silicon supplements are widely used, though there is wide variation in silicon bioavailability, ranging from values below 1% up to values close to 50%, depending on the chemical form. Therefore, the aim of this study was to evaluate the scientific literature related to the different chemical forms of silicon supplements available and the limitations and recent progress in this field. According to reported studies, among the different chemical forms available, the orthosilicic acid (OSA) presents the higher bioavailability, whereas the others forms have absorption inversely proportional to the degree of polymerization. However, clinical studies evaluating safety and efficacy are still lacking.

Calcium silicate when applied to the soil may cause changes in the chemical soil since it is a source of silicon, calcium and magnesium. The objective of this study was to evaluate the effect of calcium silicate on the chemical properties of an Oxisol. The experiment was conducted in a greenhouse with a randomized complete block design, with five doses of calcium silicate (0, 1.2, 2.4, 4.8 and 9.6 t ha-1) and four replicates. We evaluated the soil chemical properties. Silicon fertilization increases the content of Si, Ca and Mg, pH values, and SB and V%, and reduces the potential acidity (H + Al) of the soil.

An improvement in soil chemical properties and crop development with silicate application has been confirmed in several plant species. The effects of silicate application on soil chemical properties and wheat growth were investigated in the present study. The experiment was carried out in 8-L plastic pots in a greenhouse. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha–1 of calcium/magnesium silicate), with four replications. The plant length, number of spikes per pot, shoot dry matter and grain yield, were measured after 115 days of wheat (Triticum aestivum L.) growth. Changes in the soil chemical properties (pH, H+ + Al3+, Al3+, P, K, Ca, Mg, Si, Cu, Zn, Fe and Mn) were analyzed after wheat harvest. Application of calcium/magnesium silicate reduces the potential acidity (H+ + Al3+) and Al3+ phytotoxic; and increases the soil pH, available Ca, Mg and Si, cation exchange capacity (CEC) and soil base saturation. Silicate application did not affect the available P, exchangeable K and availability of micronutrients (Cu, Zn, Fe and Mn) in the three soils. The application of calcium/magnesium silicate in an acid clayey Rhodic Hapludox improves the development and yield of wheat; however, the silicate application in soil with pH higher to 5.3 and high Si availability does not affect the agronomic characteristics and grain yield of wheat.

The use of solar energy is growing sharply in the past years. The most used material for solar cells is high-purity silicon produced by refining low-purity silicon. With the increasing demand for photovoltaic components, new refining processes have been investigated. Carbon is one of the impurities to be removed and one possible removing technique is based on the settling of silicon carbide particles. Settling tests were carried out at 1,500°C during one and six hours. Results show that differences in settling time do not affect carbon removal significantly and that the carbon contents after settling are still higher than that required by standards for solar grade silicon (43 ppm). Results from this work and from literature show that settling is not a feasible processing step for carbon removal to the level needed for photovoltaic applications.

This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi) (98.5% to 99% Si). Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP), and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

The high carbon steels with bainitic constituents present very interesting mechanical characteristics, such as good ductility, high mechanical resistance to fatigue and high fracture toughness. In this work, two cast and hot-formed alloys were studied, varying the silicon contents (1.5% and 2.0%), to verify their effect on the morphology and kinetics of the bainite transformation during austempering heat treatment at 280 °C wth times varying between 1 min and 839h. Temperatures Bs and Ms were determined from thermodynamic simulations. For the morphological and kinetic characterization, the techniques of optical microscopy (OM) and scanning electron (SEM) were used, the mechanical properties were determined by tensile and hardness tests. A higher bainitic ferrite volume fraction was detected for the alloy with higher Si content. The average ultimate tensile stress (UTS) ranged from 1200 to 1600 MPa and the yield stress ranged from 1000 to 1200 MPa, with a mean hardness of 50 HRC for the samples in the bainitic reaction stage. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A simple preconcentration method of silicon based on coprecipitation with aluminum hydroxide prior to its flame atomic absorption (FAAS) determination was established. The recovery values of analyte ion was higher than 95%. The parameters including types of hydroxide ion source for precipitation, acid type for dissolution step, amount of aluminum ion as collector, pH, temperature, standing and centrifuge time, and sample volume were optimized for the quantitative recovery of the analyte. The influences of matrix ions were also examined. The relative standard deviation was found to be 3.2%. The limit of detection was calculated as (0.1 mg L-1). The preconcentration factor is 100 for (200 mL) solution. The proposed method was successfully applied for the determination of silicon in some water and alloy samples.

This study aimed to evaluate the effect of Si (stabilized silicic acid, Silamol®) leaf application on mineral nutrition and yield in upland rice and corn crops. The treatments were the control (without Si) and Si foliar split spraying using 2 L ha-1 of the Silamol® commercial product, with 0.8% soluble Si as concentrated stabilized silicic acid. Silicon leaf application increased the concentrations of K, Ca and Si in rice and corn leaves, the number of panicles per m2 of rice and the number of grains per ear of corn; accordingly, the Si leaf application provided a higher grain yield in both crops.

The aim of this work was to evaluate effect of the application of basalt powders from three different origins via soil (incorporation) and aerial (spraying) application in the performance of lettuce plants and in the population dynamics of phytophagous insects, respectively. Lettuce seedlings cv. Verônica at 8 days after emergence were transplanted to raised beds after the incorporation of the basalt powders. The effects on plant development were evaluated 50 days after transplantation and the parameters assessed were: plant height, growth of root system, dry mass, insertion diameter, volume of the root system and chlorophyll and carotenoid contents. Insect population dynamics was performed after the application of 100 g of basalt powder diluted in two liters of water (2 L ha) through four sprayings with intervals of 10 days between each. Sampling was performed daily and the insects collected were separated and identified. There was a significant increase in the variables plant height, growth of root system and dry mass in the treatments with the incorporation of basalt powder in the soil when compared to the control treatment. There was also a significant increase of 36% and 20% in the chlorophyll and carotenoid contents in lettuce leaves, respectively. There was no significant difference in the volume of the root system and insertion diameter between the treatments. The aerial spraying on lettuce plants with different basalt powders directly influenced the insect population dynamics with a significant decrease in the number of insects collected in all treatments. [ABSTRACT FROM AUTHOR]

A aplicação de silício (Si) é benéfica às plantas. Porém, existem dúvidas sobre a eficiência do seu fornecimento via foliar. Objetivou-se com este trabalho avaliar o efeito da aplicação de Si via foliar, na forma de ácido silícico estabilizado (fonte recém-desenvolvida), na nutrição e na produtividade das culturas da soja, feijão e amendoim. O delineamento experimental para cada cultura foi em blocos casualizados, com quatorze repetições. Os tratamentos foram: controle (sem aplicação de Si) e aplicação de Si via foliar, na dose de 2 L ha-1 do produto Silamol® (0,8% de Si solúvel como um concentrado estabilizado de ácido silícico). A dose de Si foi parcelada em quatro aplicações. A aplicação via foliar elevou os teores de Si, proporcionando aumento do número de vagens e da produtividade de grãos das três culturas. O incremento foi da ordem de 14; 15 e 9,6%, respectivamente, para as culturas da soja, feijão e amendoim.The application of silicon (Si) is beneficial to plants. However, there are doubts about the efficiency of foliar application. The objective of this work was to evaluate the effect of foliar application of Si, in the form of stabilized silicic acid (a newly developed source), on the nutrition and productivity of crops of soybean, common bean and peanut. The experimental design for each crop was of randomized blocks with fourteen replications. The treatments were foliar application of Si at a dosage of 2L ha-1 of Silamol ® (0.8% soluble Si as a stabilised concentrate of silicic acid) and a control (without the application of Si). The Si was divided into four applications. Foliar application increased the Si content, providing an increase in the number of pods and a higher seed yield in all three crops. The increase was around 14; 15 and 9.6%, respectively, for the soybean, common bean and peanut.

The main objective of the present work is to study the macrosegregation of impurity elements during the unidirectional solidification of metallurgical grade silicon. A cylindrical ingot was obtained by melting and solidification of metallurgical grade silicon in a resistance furnace. Macrographs and micrographs of the longitudinal section of the ingot were examined. These reveal a grain structure consisting mainly of columnar grains and intermetallic precipitates concentrated at the ingot top. The remaining part of the ingot was free from any type of intermetallic. The compositions of samples extracted along the ingot were measured by chemical analysis, enabling the construction of concentration profiles. These profiles show an accumulation of impurity elements at the ingot top, indicating the macrosegregation of these elements and an effect of refining the initial composition.

Metalloids have characteristics between metals and non-metals which give them, in some cases, specific properties. At least two of this chemical elements, boron and silicon, are essential to a significant number of living organisms and since some years ago it has been observed that the same metalloids may be involved in the synthesis and stabilization of some molecules relevant to the origin of life.

Silicates can be used as soil correctives, with the advantage of being a source of silicon, a beneficial element to the grasses. However, high concentrations of silicon in the plant would affect the digestibility of the forage. To evaluate the influence of the substitution of the calcium carbonate by calcium silicate on the nutrition, biomass production and the feed quality of the palisade grass [Urochloa brizantha (C. Hochstetter ex A. Rich.) R. Webster], three greenhouse experiments were conducted in completely randomized designs with four replications. Experimental units (pots) contained a clayey dystrophic Rhodic Haplustox, a sandy clay loam dystrophic Typic Haplustox and a sandy loam dystrophic Typic Haplustox. Each soil received substitution proportions (0, 25, 50, 75 and 100 %) of the carbonate by calcium silicate. The increase in the proportion of calcium silicate elevated the concentrations and accumulations of Si, Ca, Mg, and B, reduced Zn and did not alter P in the shoot of plants. The effects of the treatments on the other nutrients were influenced by the soil type. Inclusion of calcium silicate also increased the relative nutritional value and the digestibility and ingestion of the forage, while the concentration and accumulation of crude protein and the neutral detergent and acid detergent fibers decreased. Biomass production and feed quality of the palisade grass were generally higher with the 50 % calcium silicate treatment.

Application of calcium silicate (SiCa) as soil acidity corrective was evaluated in a Rhodic Hapludox soil with palisade grass conducted under pasture rotation system with different grazing intensities. Experimental design was complete randomized blocks with four grazing intensities - grazing intensities were imposed by forage supply (50, 100, 150 and 200 kg t-1 of DM per LW) - in experimental plots with four replicates and, in the subplots, with seven doses of calcium silicate combined with lime: 0+0, 2+0, 4+0, 6+0, 2+4, 4+2 and 0+6 t ha-1, respectively. In the soil, it was evaluated the effect of four levels of calcium silicate (0, 2, 4 and 6 t ha-1) at 45, 90, and 365 days at three depths (0-10, 10-20 and 20-40 cm) and at 365 days, it was included one level of lime (6 t ha-1). For determination of leaf chemical composition and silicate content in the soil, four levels of calcium silicate (0, 2, 4 and 6 t ha-1) were evaluated at 45 and 365 days and at 45 days only for leaf silicate, whereas for dry matter production, all corrective treatments applied were evaluated in evaluation seasons. Application of calcium silicate was positive for soil chemical traits related to acidity correction (pH(CaCl2), Ca, Mg, K, H+Al and V), but the limestone promoted better results at 365 days. Leaf mineral contents were not influenced by application of calcium silicate, but there was an increase on silicate contents in leaves and in the soil. Dry matter yield and chemical composition of palisade grass improved with the application of correctives.

O biótipo B de Bemisia tabaci destaca-se entre as pragas principais do feijoeiro. Neste trabalho, objetivou-se avaliar a indução de resistência à mosca-branca pela aplicação de silício em feijoeiro. Foram testados 4 tratamentos, em esquema fatorial 2 (cultivares Carioca e Valente) x 2 (com e sem aplicação de silício) e 6 repetições. Dez dias após a emergência das plântulas, foram aplicados 500 ml de solução de ácido silícico a 1% no solo, na dosagem equivalente a 2 t SiO2/ha. Dez dias após a aplicação do silício, as plantas foram infestadas com adultos não sexados de mosca-branca em sala climatizada, sendo 100 moscas-brancas/vaso. Para o teste sem chance de escolha, o mesmo procedimento foi utilizado, com cada vaso coberto por gaiolas de tecido organza. Anteriormente à infestação, uma planta de cada vaso foi retirada, seca em estufa até peso constante para avaliação do teor de fenóis. Após 48 horas de infestação, os adultos liberados foram removidos das plantas para avaliação do número de ovos. Para isso, foi escolhida uma folha de uma planta/vaso, selecionando-se a terceira folha apical inteiramente desenvolvida. Após quinze dias, foi avaliado o número de ninfas de 3° e/ou 4° ínstar. Não houve resposta entre cultivares de feijoeiro à aplicação de silício. Foi observado menor número de ovos e menor número de ninfas nas plantas tratadas com silício no teste com chance de escolha. No teste sem chance de escolha, a aplicação de silício não afetou a oviposição da mosca-branca e o desenvolvimento das ninfas, bem como o teor de fenóis.The biotype B of Bemisia tabaci stands out among the main pests of the bean plant. The objective of this work was to evaluate the resistance induction to the whitefly by silicon application in bean plant. The experimental design was completely ranlomized with 4 treatments, in a 2 (cultivar Carioca and Brave) x 2 (with and without silicon application) factorial outline and 6 repiicates. Ten days after the emergence of the seedlings, 500 ml of 1% silicic acid solution was applied in the soil, at a dosage equivalent to 2 t SiO2/ha. Ten days after the silicon application, the plants were infested with non-sexed whitefly adults in an acclimatized room, wiht 100 whiteflys/vase. For the non-choice test, the same procedure was used, with each vase covered by cages of organza cloth. Previously to the infestation, a plant of each vase was removed, oven-dried to constant weight for the evaluation of phenol levels. After 48 hours of infestation, the liberated adults were removed from the plants for evaluation of the number of eggs. For that, a leaf of a plant/vase was chosen, selecting the third completely developed apical leaf. After fifteen days, the number of nymphs of 3rd and/or 4th instar were evaluated. There was no response among cultivars of common bean to silicon application. A lower number of eggs and lower number of nymphs were observed in the plants treated with silicon in the test with chance choice. In the no-choice test the silicon application did not affect the oviposition of the whitefly and the nymph development, as well as the phenol levels.

A realização de estudo da adubação silicatada em roseiras é justificada com o intuito de reduzir o número de aplicações de defensivos agrícolas, podendo aumentar a produtividade e a qualidade dos botões florais na colheita e pós-colheita. A absorção de silício difere entre as espécies vegetais. Há evidências de que o envolvimento dos silicatos na indução de resistência pode ocorrer pela participação do próprio silício, fortificando estruturas da parede celular, conferindo aumento da lignificação. Baseando nos benefícios desse elemento, realizou-se o experimento para avaliar o efeito da adubação silicatada no teor de clorofila, em folhas de roseiras. O experimento foi instalado em casa de vegetação, em chácara comercial de produção de rosas, da variedade Versília®. Os tratamentos testados consistiram da aplicação de silício utilizando-se como fonte o silicato de potássio, acrescido ou não de fosfito. Utilizaram-se 4 doses de silício: 0, 427,5; 855 e 1282,5 mg L-1, que corresponde a 0; 0,25; 0,5 e 0,75% na calda de pulverização. O delineamento utilizado foi em blocos casualizados, em esquema fatorial (2x4). As aplicações das doses 0,25 e 0,50% de silicato de potássio na calda foliar em roseira influenciaram os teores de clorofila a, b e clorofila total das folhas, proporcionando maiores teores em comparação com os demais tratamentos.The study of silicate fertilization in crop roses is justified with the purpose of reducing the use of defensives, increasing yield, and enhancing the quality of stem flowers in harvest and postharvest. The uptake of silicon is different among species. There is evidence that silicates involved in resistance induction can occur with the participation of silicon itself, reinforcing cellular wall (apoplast) structures and increasing lignification. Based on the benefits of this element, an assay was carried out to evaluate the effect of silicate fertilization on the chlorophyll content of rose leaves, cultivar Versília®, in a commercial greenhouse. The effect of potassium silicate with and without phosphite (1:1) in four silicon (Si) concentrations: 0; 427.5; 855 and 1285.5 mg L-1, that corresponds to 0; 0.25; 0.5 and 0.75% in foliar spray were tested. The treatments were laid out in randomized blocks in a (2x4) factorial scheme. The use of 0.25 and 0.5% potassium silicate in leaf spray in crop rose, influenced the content of chlorophyll a, b, and total chlorophyll of leaves, providing higher levels than other treatments.

A soja [Glycine max (L.) Merrill] é o principal produto agrícola da exportação brasileira, portanto, torna-se importante a realização de estudos que contribuam para a minimização dos efeitos que possam causar a diminuição do rendimento e a depreciação da qualidade dessa oleaginosa, como a ocorrência de pragas e doenças, problemas com a fertilidade do solo e adversidades climáticas, entre outros. Sabe-se que as plantas diferem na sua capacidade de absorver silício (Si), sendo assim diferentemente classificadas. A influência do Si no desenvolvimento vegetativo em plantas de soja ainda é pouco conhecida, existindo poucos estudos descritos na literatura. Diante disso, objetivou-se, neste trabalho, avaliar a resposta da soja a diferentes doses de Si no plantio, por meio da produtividade e características agronômicas das plantas no campo. O delineamento experimental utilizado foi o de blocos casualizados (DBC), com três repetições, tendo como tratamentos 11 doses de Si (0, 50, 100, 150, 200, 250, 300, 350, 400, 450 e 500 kg ha-1) na semeadura da soja, cultivar BRS MG 68 Vencedora. As doses de Si utilizadas não proporcionaram aumentos significativos na produtividade de grãos, peso de mil sementes, número de sementes por legume, o mesmo não se verificando com o numero de legumes por planta, altura de planta e altura de inserção do primeiro legume que apresentaram efeito significativo, com o aumento das doses nessas características. A aplicação de Si não proporcionou efeitos fitotóxicos visíveis na planta de soja.Soybean [Glycine max (L.) Merrill] is the main agricultural product export of Brazil. Therefore, it is important studies that contribute to the mitigation of the effects that might cause a decrease in income and depreciation of the quality of this oleaginous plant, as the occurrence of pests and diseases, problems with soil fertility and climatic adversities, among others. It is known that plants differ in their ability to absorb silicon (Si) and are therefore classified differently. The influence of vegetation on Si in the development of soybean plants is still little known, and there are few studies described in the literature. Facing this, the objective of this work was to evaluate the response of soybean plants to variable dosage of silicon in the plantation, through agronomical characteristics of the plants in the field. The experimental design was a completely randomized block (CBD), with three replicates, eleven treatments with the following doses of silicon (0, 50, 100, 150, 200, 250, 300, 350, 400, 450 and 500 kg ha - 1) in the soybean planting, cultivating BRS MG 68 Vencedora. Doses of silicon used did not provide significant increases in seed yield, weight of a thousand seeds, and number of seeds per vegetable, but the number of vegetables per plant, plant height and time of insertion of the first vegetable increased significantly with higher doses. Application of silicon did not have phytotoxic effects on the soybean plant.

The greenbug Schizaphis graminum (Rond.) (Hemiptera: Aphididae) is one of the main pestinsects of wheat (Triticum aestivum, L.). Resistance inducing agents as silicon (Si) and acibenzolar-s-methyl (ASM) can provide some protection against insects and diseases. The effect of Si and/or ASM on the development and probing behaviour of S. graminum in wheat plants was evaluated. Wheat plants (cultivar Embrapa 22) were treated with Si (silicic acid at the rate of 1%) and acibenzolar-S-methyl (ASM) at the rate of 0.5%. The effects of these treatments on greenbugs were analyzed by development parameters, honeydew excretion and probing behavior monitored by Electrical Penetration Graphs (EPG). The development and honeydew experiments consisted of ten replications each and EPG experiment was replicated 25 times. The application of both resistance inducing agents reduced fecundity, prolonged the duration of pre-reproductive period, and decreased honeydew production. Induced resistance was localized mainly at phloem level and caused a strong reduction of phloem sap ingestion, but some effect of ASM at parenchyma/mesophyll level could not be discounted as far fewer aphids reached the sieve elements.O pulgão-verde Schizaphis graminum (Rond.) (Hemiptera: Aphididae) é um dos principais insetos- praga da cultura do trigo (Triticum aestivum, L.). Agentes que induzem resistência como silício e acibenzolars-methyl (ASM) podem fornecer proteção às plantas contra insetos e doenças. Avaliou-se o efeito do silício e/ ou ASM no desenvolvimento e comportamento alimentar de S. graminum em plantas de trigo. Plantas de trigo cultivar Embrapa 22 foram tratadas com silício (ácido silícico a 1%) e acibenzolar-S-methyl (ASM) a 0.5%. Os parâmetros estudados foram biologia, excreção de honeydew e comportamento alimentar (de prova) monitorado por meio da técnica Electrical Penetration Graphs (EPG). Para o estudo de biologia e excreção de honeydew foram usadas dez repetições e 25 para EPG. A aplicação de agentes indutores de resistência reduziu o número de ninfas, prolongando a duração de período de pré-reprodutivo e o número de gotas de honeydew. O efeito de resistência foi localizado principalmente no floema, com redução de ingestão de seiva elaborada.

As escórias siderúrgicas são usadas na agricultura, mas são poucos os trabalhos sobre sua reatividade. Neste trabalho, objetivou-se avaliar escórias siderúrgicas em diferentes frações granulométricas quanto à correção do pH e liberação de Ca, Mg e Si para o solo. O delineamento foi inteiramente casualizado com 4 repetições em esquema fatorial com 6 fontes (escória de alto-forno 1, escória de fosfato, escória de alto-forno 2, escória de aciaria de forno AOD, escória de aço inox e escória de forno LD) e 5 distribuições granulométricas (2 - 1,41; 1,41 - 0,85; 0,85 - 0,50; 0,50 - 0,30 mm e < 0,30 mm) e dois tratamentos adicionais (testemunha e CaCO3). O CaCO3 foi usado como padrão para a determinação do índice de reatividade de cada escória. Foram aplicados 1500 mg kg-1 de equivalente CaCO3 e em todos os tratamentos e as doses de cada escória foram calculadas pelo seu PN-determinado. Houve aumento do pH com a redução do tamanho das partículas para todas as escórias. A escória de fosfato apresentou maior eficiência na liberação de Ca + Mg em relação ao carbonato quando o tamanho das partículas foi menor que 0,5 mm. Houve baixa eficiência na correção da acidez e liberação de Ca e Mg no solo nas.escórias de alto forno. Para maior liberação de silício, é necessário utilizar partículas de tamanho menor (The slags are used in the agriculture as soil acidity correctives in same rates of lime, but there are few studies about its reactivity in soils. The objective was to compare slag reactivity to soil acidity correction and calcium, magnesium, and silicon liberation. A completely randomized experimental design was used, with 4 repetitions in factorial with 6 sources (blast furnace slag 1, phosphate slag, blast furnace slag 2, AOD furnace steel slag, stainless steel slag and LD furnace steel slag) and 5 particle sizes (2-1.41; 1.41-0.85; 0.85-0.50; 0.50-0.30 mm and < 0,30 mm) and two additional treatments (control and CaCO3). The CaCO3 was used as a pattern for the determination of the reactivity index of each source. All treatments received 1500 mg kg-1 of equivalent CaCO3 and each rate of slags was calculated by its determined neutralization power. The pH-value increased with reduction of particle size in all slags. The phosphate slag showed best efficiency on the liberation of Ca + Mg compared to the calcium carbonate in the granulometrics inferior to 0.5 mm. There was low efficiency in soil acidity correction and liberation of the Ca and Mg in soil to slag of blast furnace. It is necessary to use particles smaller than 0.3 mm to improve silicon availability of phosphate slag and particles between 0.85 and 1.41mm to stainless steel slag. The silicon availability of AOD furnace steel slag and LD furnace steel slag were not influenced by particle size.

Neste trabalho, objetivou-se avaliar o efeito de diferentes doses de silicato de cálcio sobre a população de ninfas de percevejo castanho das raízes em Brachiaria brizantha, nas características químicas do solo, planta e produção de matéria seca. O experimento foi conduzido em blocos casualizados, com cinco tratamentos e quatro repetições, totalizando 20 parcelas. Os tratamentos testados foram cinco doses (0, 0,5, 1, 2, e 4 t ha-1) de silicato de cálcio aplicadas junto com a adubação NPK na implantação da B. brizantha. Foi avaliado o número de ninfas do percevejo (profundidade de 0 a 40 cm), o pH e os teores de cálcio e de silício no solo. Aos 120 dias do plantio, a gramínea foi cortada, determinando-se a composição química e a produção de massa seca. Verificou-se que a aplicação de 2,6 t ha-1 de silicato de cálcio foi a melhor dosagem estimada para a redução de ninfas do percevejo castanho das raízes. A aplicação de doses crescentes de silicato de cálcio no solo promoveu o incremento do pH, dos teores de cálcio e silício no solo e o aumento na produção de matéria seca de B. brizantha.The objective of this study was to evaluate the effects of different calcium silicate rates on the nymph population of the brown root stinkbug in B. brizantha cv. marandu, in the soil chemical characteristics, and plant and dry matter production. The experiment was carried out in casualized blocks with five treatments and four repetitions, in a total of 20 plots. The treatments tested were five rates (0, 0.5, 1, 2, and 4 t ha -1) of calcium silicate applied together with NPK fertilization in the implantation of B. brizantha. The nymph number (depths 0 to 40 cm), pH, and soil calcium and silicon content were evaluated. On the 120th day after sowing, the grass was cut to determine the chemical composition and dry matter production. It was verified that the application of 2.6 t ha -1 of calcium silicate was the best estimated rate for the reduction of brown root stinkbug nymphs. The application of increasing doses of calcium silicate in the soil caused an increase of the pH, calcium and silicon content in the soil, and an increase in B. brizantha dry matter production.

Objetivou-se, neste trabalho, avaliar o efeito da aplicação de indutores na resistência de duas cultivares de soja à mosca-branca Bemisia tabaci biótipo B. O experimento foi conduzido no Departamento de Entomologia - UFLA. As sementes de soja, cultivar IAC-19 e MONSOY-8001, foram previamente tratadas com o fungicida captan. Foram testados os seguintes tratamentos: T1- irrigação no solo, ao redor das plantas de cada vaso, de 250 mL de solução de ácido silícico a 1%; T2- pulverização das plantas, até o ponto de escorrimento, com solução a 0,3% de acibenzolar-s-methyl; T3- pulverização das plantas, até o ponto de escorrimento, com calda a 0,24% de pyraclostrobin+epoxiconazole e T4- testemunha. As plantas foram infestadas com 100 adultos da mosca-branca por vaso que liberados oito dias após a aplicação dos tratamentos. Avaliaram-se o número de ovos na face abaxial de cada folha, que foi marcada para posterior avaliação de ninfas; teores de taninos e de lignina; peso seco das raízes e da parte aérea. Não houve diferença para número de ovos e ninfas entre as cultivares de soja, porém, a viabilidade média de B. tabaci foi menor a cultivar IAC-19. O cultivar de soja IAC-19 demonstrou moderada resistência ao biótipo B de B. tabaci. A aplicação de silício ou acibenzolar-s-methyl induz um aumento no teor de lignina na cultivar de soja IAC-19.The objective of this paper was to evaluate the effect of the application of inducers on the resistance of two soybean cultivars to the whitefly B. tabaci Biotype B. The experiment was carried out at the Entomology Department - UFLA. The soybean seeds of cultivars IAC-19 and MONSOY-8001 were previously treated with Captan fungicide. The following treatments were tested: T1- irrigating the soil around the plants of each pot with 250 mL of solution of 1% silicic acid; T2- spraying of the plants, to the 'point of dripping', with a solution of 0.3% acibenzolar-s-methyl; T3- spraying of the plants, to the 'point of dripping', with a solution of 0.24% pyraclostrobin+epoxiconazole, and T4- control. The plants were infested with 100 adult whiteflies that were released eight days after applying the treatments. The number of eggs on the abaxial face of each leaf, which was marked for further evaluation of nymphs, tannin and lignin contents, dry weight of the aerial parts and roots, was evaluated. There was no difference for the number of eggs and nymphs among the soybean cultivars. Nevertheless, the average survival rate of B. tabaci was lower on cultivar IAC-19. The application of silicon or acibenzolar-s-methyl induces an increase in lignin content in the soybean cultivar IAC-19.

A mancha bacteriana do maracujá, causada pela bactéria Xanthomonas axonopodis pv. passiflorae, ocorre em todas as regiões produtoras do País, sendo responsável por grandes perdas econômicas na cultura do maracujazeiro-amarelo. O presente trabalho teve como objetivos testar a eficiência de argila silicatada na inibição da bactéria X. axonopodis pv. passiflorae in vitro e no controle preventivo e curativo da mancha bacteriana em mudas de maracujazeiro-amarelo. A argila silicatada foi adicionada ao meio de cultura batata-dextrose-ágar fundente, nas concentrações de 0,0; 0,5; 1,0; 1,5 e 2,0%; vertido em placas de Petri. Após resfriamento do meio, repicou-se a suspensão bacteriana (10(7) UFC.mL-1) com uma alça, incubando-se as placas a 28 °C por três dias, quando se avaliou o crescimento bacteriano. Posteriormente, o produto, nas mesmas concentrações citadas, foi pulverizado em mudas de maracujá 'Afruvec' de forma preventiva ou curativa. A inoculação da bactéria foi realizada através de pulverização foliar da suspensão bacteriana (10(7) UFC.mL-1), 24 h antes ou após os tratamentos curativo e preventivo, respectivamente. A severidade da doença foi avaliada com auxílio de uma escala diagramática nas quatro primeiras folhas verdadeiras contadas de baixo para cima. Nas concentrações avaliadas, a argila silicatada inibiu a bactéria in vitro e os sintomas da mancha bacteriana no tratamento curativo, enquanto no tratamento preventivo, controle significativo foi obtido a partir de 1,0% de argila silicatada. Com base nestes resultados, a argila silicada pode ser recomendada, na concentração de 1,0-2,0%, para o controle da mancha bacteriana do maracujazeiro em pulverizações foliares.The bacterial spot in yellow passion fruit plants, caused by the bacteria Xanthomonas axonopodis pv. passiflorae, occurs in all producing areas of the country, and is responsible for great economic losses in the culture of passion fruit. This study aimed to test the efficiency of the silicate clay in the inhibition of the bacteria Xanthomonas axonopodis pv. passiflorae in vitro, and in both preventive and curative control of the bacterial spot in seedlings of yellow passion fruit plants. The silicate clay was added to the growth medium at concentrations of: 0.5, 1.0, 1.5 and 2.0%, placed in Petri dishes. After the culture medium was cooler, the bacterial suspension was inoculates (10(7) UFC.mL-1) with a handle, and left incubating at 28 ° C for three days, and then the bacterial growth was evaluated. Subsequently, the product at the same concentrations above was sprayed on seedlings of 'Afruvec' passion fruit, as preventive or curative. The inoculation of the bacteria was made by foliar spraying of bacterial suspension (10(7) ufc.mL-1), 24 hours before or after the curative and preventive treatments, respectively. The severity of the disease was measured comparing each four true leaves from bottom up, with a diagrammatic scale. In the concentrations evaluated, the silicate clay inhibited both bacteria in vitro and symptoms of bacterial spot in the curative treatment. In preventive treatment, significant results were obtained using more than 1.0% of clay silicates. Based on these results, the clay silicate can be recommended, the concentration of 1.0-2.0% for the control of bacterial spot of passion fruit plants, in foliar sprays.

O cultivo orgânico de batata inglesa apresenta viabilidade econômica, porém enfrenta problemas em relação à manutenção da sanidade. Este trabalho foi realizado para verificar o efeito da adubação com silício na incidência de insetos-praga e na produtividade da cultura da batata inglesa em sistema orgânico. Foram testados 5 tratamentos com 4 repetições: 1- testemunha; 2- adubação via solo com ácido silícico, na dose correspondente a 0,35t.ha-1; 3- adubação via foliar com solução de ácido silícico a 0,35%; 4- adubação via solo com pó de rocha, na dose correspondente a 2t.ha-1; 5-adubação via foliar com solução de pó de rocha a 2%. Os tratamentos foram aplicados 20 dias após o plantio da batata-semente. Foi monitorada a incidência de insetos-praga por meio da determinação do número pulgões, de lesões foliares provocadas por Diabrotica speciosa (Germar) e de folíolos minados por Liriomyza spp.. Determinaram, ainda, a altura e o diâmetro das plantas e a produtividade. Verificou-se que as plantas adubadas com silício, independentemente da forma de aplicação e da fonte utilizada, apresentaram menor número de injúrias foliares em relação àquelas da testemunha. Contudo, não foi constatado o efeito da adubação com silício no desenvolvimento e produtividade da cultura.The organic cultivation of potato presents economical viability, however it faces problems in relation to the maintenance of sanity. This work was carried out to verify the effect of the silicon fertilization on the incidence of pest insects and in the productivity of potato in an organic system. Five treatments were tested, with four replications: 1- control; 2- fertilization applied via soil with silicic acid, in the dose corresponding to 0.35t.ha-1 3- fertilization applied via leaf with solution of silicic acid at 0.35%; 4- fertilization applied via soil with rock powder, in the dose corresponding to 2t.ha-1; 5- fertilization applied via leaf with rock powder solution at 2%. The treatments were applied 20 days after the plantation of the seed potato. The incidence of pest insects was monitored by means of the determination of the number of foliar lesions caused by Diabrotica speciosa (Germar) and the number of leaves mined by Liriomyza spp. The diameter and the height of the plants and the productivity were determined. Independently of the form of application and the source used, it was verified that the plants fertilized with silicon presented lower number of leaf injuries in relation to the control ones. However, it was not possible to verify the effect of the fertilization with silicon on the development and productivity of the culture.

For the construction of the phase diagrams, the method of the aqueous titration was used. There were prepared 5 ternary diagrams, varying the surfactant and the oil phase. The liquid-crystalline phases were identified by polarized light microscopy. The formulations prepared with silicon glycol copolymer, polyether functional siloxane (PFS) and water (S1) and with diisopropyl adipate, PFS and water (S4) presented liquid-crystalline phases with lamellar arrangement. Moreover, after 15 days in hot oven (37 ºC), the formulations presented hexagonal arrangement, evidencing the influence of the temperature in the organization of the system.

Objetivou-se avaliar o efeito da aplicação de silício em parâmetros biológicos e na morfometria de C. atlantica. O bioensaio foi conduzido em sala climatizada com temperatura de 20ºC, 70% UR e fotofase de 12 horas, com delineamento experimental inteiramente casualizado. Fêmeas adultas obtidas após a última ecdise ninfal foram transferidas para as unidades experimentais (gaiolas de PVC) e, entre o 4º e 5º dia reprodutivo, a fêmea foi retirada e dentre os descendentes produzidos nesse período, um foi escolhido aleatoriamente para a condução do ensaio. Nos tratamentos com a aplicação de diferentes doses do ácido silícico, ocorreram prolongamento da fase ninfal e redução na performance biológica, afetando assim o ciclo biológico do pulgão. Em relação à capacidade reprodutiva do inseto, obtiveram-se, para os tratamentos com aplicação do ácido silícico, valores distintos da testemunha que apresentou número elevado de ninfas/fêmea. Em relação à morfometria, dentre os quinze caracteres avaliados, apenas a largura da cabeça e o comprimento total da antena de C. atlantica, que foram mantidos em plantas com aplicação de silício, diferiram estatisticamente da testemunha.This research aimed to study the effect of silicon in biology and morphology of C. atlantica. The bioassay was carried out in environmental chamber (20ºC, 70% RH and 12 photophase) in a completely randomized design. Adult females were transferred to experimental units (PVC cages) after the last nymphal ecdysis and were removed from these sites between the 4th and 5th reproductive day. From this offspring, one specimen was randomly chosen to take part the experiment one observed an increase in nymphal phase and a decrease of aphid fitness in treatments with different levels of silicon. In relation to the reproductive capacity of the insect one gotten for the treatment with application the treatment with application silicic acid distinct values of the witness presented high number of nymphs/female. Fifteen characters were surveyed in the morphometry analysis, from which the width of the head and the total length and of antenna of C. atlantica were kept in plants with silicon application differed statistically from control.

One of the greatest problems for pasture establishment and maintenance are the extremely low concentrations of available phosphorus in soils. The objective of this study was to evaluate the influences on productive and physiologic attributes during Marandu palisadegrass (Brachiaria brizantha) establishment, following changes in phosphorus availability in the soil through the applications of phosphate and silicate. To achieve this, a fractionated factorial 5² design was used, with 13 combinations for silicon and phosphorus, respectively, in mg dm-3: 150 and 10; 150 and 170; 150 and 330; 225 and 90; 225 and 250; 300 and 10; 300 and 170; 300 and 330; 375 and 90; 375 and 250; 450 and 10; 450 and 170 and 450 and 330, distributed according to randomized blocks, with four replications. The experiment was carried out in a greenhouse using samples of a Typic Haplustox (760 g kg-1 sand, 40 g kg-1 silt and 200 g kg-1 clay). Wollastonite was used as the source of silicate and the sources of phosphorus were Ca(H2PO4)2, KH2PO4 and NaH2PO4. Marandu palisadegrass was grown during the summer and two harvests were made during the growing season. Significant interaction between phosphorus and silicate rates was found for the number of tillers and expanded green leaves, total leaf area, dry mass production of leaf laminae and culms with sheaths, and dry mass production of plant tops. Maximum responses of the analyzed variables were reached in the combination of the intermediate rates of phosphorus (170 and 250 mg dm-3) with high rates of silicon (375 and 450 mg dm-3).Um dos maiores problemas no estabelecimento e na manutenção de pastagens está nas concentrações extremamente baixas de fósforo disponível nos solos. Objetivou-se avaliar os atributos produtivos e fisiológicos durante o estabelecimento do capim-Marandu (Brachiaria brizantha), em seguida à alteração na disponibilidade de fósforo, por meio das aplicações de silicato e fosfato. Utilizou-se um esquema fatorial 5² fracionado, com as 13 combinações assim definidas, para silício e fósforo, respectivamente, em mg dm-3: 150 e 10; 150 e 170; 150 e 330; 225 e 90; 225 e 250; 300 e 10; 300 e 170; 300 e 330; 375 e 90; 375 e 250; 450 e 10; 450 e 170 e 450 e 330, as quais foram distribuídas segundo delineamento estatístico de blocos ao acaso, com quatro repetições. O experimento foi instalado em casa de vegetação, utilizando um Latossolo Vermelho-Amarelo Distrófico. A fonte de silício utilizada foi a wollastonita e as fontes de fósforo foram Ca(H2PO4)2, KH2PO4 e NaH2PO4. O capim-Marandu foi cultivado durante o verão e foram realizados dois cortes no capim. A interação foi significativa entre as doses de fósforo e de silício para o número de perfilhos e de folhas verdes expandidas, a área foliar total, a produção de massa seca das l��minas foliares e colmos mais bainhas e a produção de massa seca da parte aérea total. As máximas respostas das variáveis estudadas foram alcançadas na combinação das doses medianas de fósforo (170 e 250 mg dm-3) com doses altas de silício (375 e 450 mg dm-3).

This work to evaluate the effect of foliar application of Potassium Silicate (K2SiO3) and the number of fungicide applications on the content of chlorophyll and the tomato. The experiment was performed in Uberlândia, Minas Gerais, with a randomized blocks in a factorial 4 x 2 with four doses of Potassium Silicate (K2SiO3 - 12.2% Si, 15% K2O), (0, 0, 2, 0.4 and 0.6 mL 100L-1 sauce) and two managements fungicide (two three weekly applications) with four blocks. The potassium silicate was applied weekly from transplanting to the date of the last harvest, totaling 15 applications. We evaluated the levels of chlorophyll a, b and a / b ratio in the upper and lower third of the plant; the development of production and productivity and fruit classification. The K2SiO3 doses provided increases in the chlorophyll content; the contents of chlorophyll b and a / b ratio did not show significant variation; with three weekly fungicide applications were better classification of fruit, but with two weekly applications it had increased productivity; K2SiO3 doses gave productivity increases with the dose of 0.38 U 100L-1 gave the highest production of fruits and G 100L-dose 0.33 1 Total fruits. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of different concentrations of potassium silicate (K2SiO3) foliar spray under chlorophyll content, yield and quality of strawberry fruits. The work was carried in greenhouse in Jundiaí-SP. The experimental design was randomized blocks with five doses of K2SiO3 foliar spray (0, 0.2, 0.4, 0.6, 0.8 mL 100L-1 of K2SiO3). Was determinate chlorophyll A (ChlA), B (ChlB) and total (ChlT) content and chlorophyllA:chlorophyll B ratio (ChlA:ChlB), yield and fruit quality. Doses of K2SiO3 applied foliar amendment provided for all variables studied. The application of K2SiO3 was efficient in providing Si to plants and the increase in foliar Si correlated with increased levels of ChlA, ChlB, ChlT and non-reducing sugar. With the results it can be concluded that the foliar application of K2SiO3 provided increments in the levels of ChlA, ChlB and ChlT; was efficient in supplying Si to plants and provided an increase in production and fruit quality. [ABSTRACT FROM AUTHOR]

Resíduos industriais são fontes alternativas de nutrientes para as plantas e sua utilização decorre da necessidade de diminuir o acúmulo dos resíduos nos centros de produção. O objetivo deste trabalho foi avaliar o efeito de escórias de siderurgia nos atributos químicos do solo, no desenvolvimento e na produtividade de grãos do arroz de terras altas irrigado por aspersão. O delineamento experimental foi em blocos casualizados, com três tratamentos constituídos de duas escórias, alto-forno (196 g kg-1 de Si) e aciaria (56 g kg-1 de Si), e a testemunha sem aplicação, com oito repetições. As escórias podem ser usadas como corretivo de acidez do solo e como fonte de silício. As alterações nos atributos químicos do solo estão relacionadas com a composição química das escórias. A escória de alto-forno proporcionou maior crescimento radicular em profundidade e melhor distribuição no perfil do solo e, conseqüentemente, maior produção de massa de matéria seca da parte aérea e produtividade de grãos de arroz.Use of industrial residues as alternative sources of nutrients to the plants is due to the necessity of reducing their accumulation in the production sites. The objective of this work was to evaluate the effect of metallurgy slag in soil chemical attributes, in development and in grain yield of upland rice sprinkler irrigated. The experiment was carried out in a randomized block design, with three treatments constituted by two scums, blast furnace (196 g kg-1 of Si) and steel slag (56 g kg-1 of Si), and a control without application, with eight replications. The scums can be used as corrective of soil acidity and silicon source. Alterations in the soil chemical attributes are related to the chemical composition of the scums. Blast furnace slag resulted in higher root growth in depth and better distribution in the profile soil provides higher shoot dry matter yield and grain yield.

Apesar dos elevados teores de SiO2 total geralmente encontrados nos solos brasileiros, o teor na solução do solo pode ser baixo, em conseqüência do processo de dessilicificação que ocorre durante a intemperização dos solos. A aplicação de escórias de processamento industrial, ricas em silicatos de cálcio, tem mostrado efeitos positivos quanto à ação corretiva da acidez do solo e ao fornecimento de Si às plantas acumuladoras desse elemento, com aumentos significativos de produtividade. Conduziu-se este trabalho com o seguinte objetivo: avaliar em dois anos de cultivo sucessivos a ação corretiva, a produtividade de grãos e a absorção de Si pelo arroz de terras altas. Foram aplicadas ao solo de cerrado classificado como latossolo vermelho distroférrico de cerrado seis doses (0, 2, 4, 6, 8 e 10 t ha-1) de uma escória silicatada com 20% de SiO2 total, proveniente do processo de fabricação de superfosfatos em forno elétrico. Utilizou-se o delineamento de blocos completos casualizados com cinco repetições. Foram detectados aumentos significativos de produtividade de grãos, teor e acumulação de Si na palha e da porcentagem de grãos cheios por panícula, nos dois anos de cultivo do arroz. Houve ação corretiva no solo das doses de escória, reduzindo a acidez e aumentando a disponibilidade de P, Si, Ca trocável e a porcentagem de saturação por bases. O nível crítico de Si na palha por ocasião da colheita, para obtenção de produtividade satisfatória de grãos, foi estabelecido em 2,25 g kg-1 de matéria seca.Despite the high SiO2 total content often found in Brazilian soils, the soluble silicon content in soil solution can be low due to weathering that occur in soils. The application of calcium silicate slags, under these conditions, has demonstrated positive effects in relation to correction of soil acidity, the supply of Si to plants that accumulate this element and significant yield increase. The objectives of this investigation were to evaluate in two consecutive years, soil acidity correction, grain yield and Si uptake in upland rice. Six doses of calcium silicate slag with 20% of total SiO2 (0, 2, 4, 6, 8 and 10 t ha-1) in form of calcium silicate slag, a subproduct of phosphorus processed in electric furnace was applied to oxisoil. The experimental design was a randomized complete block with five repetitions. Application of calcium silicate slag resulted in significant grain yield increase, tissue silicon content and silicon accumulation in straw and the filled grain percentage in the first and in the second year of rice cultivation. The critical Si level in the rice straw required for obtaining satisfactory yield was 2,25 g kg-1 of dry matter. In soil, the application of calcium silicate slag reduced soil acidity and increased available P, Si, exchangeable Ca, and saturation of bases. There was significant correlation between soluble Si extracted in acetic acid extraction 0.5 mol L-1 and water, in relation to soluble Si content found in soil after rice cultivation.

Silicon is not considered an essential element for plant development and growth, but its absorption brings several benefits to some crops, especially rice, by increasing cellular wall thickness, providing mechanical resistance to the penetration of fungi, improving the opening angle of leaves and making them more erect, decreasing self-shading and increasing resistance to lodging, especially under high nitrogen rates. To evaluate the effects of nitrogen and silicon fertilization on vegetative and yield components, plant height, and yield of rice cultivar IAC 202, an experiment was carried out combining three nitrogen rates (5, 75 and 150 mg N kg-1 soil) applied as urea, and four silicon rates (0, 200, 400 and 600 mg SiO2 kg-1 soil) applied as calcium silicate. Trial was set up in a completely randomized design 3 ´ 4 factorial scheme, (N = 5). Nitrogen fertilization increased the number of stems and panicles per square meter and the total number of spikelets, reflecting on grain productivity. Excessive tillering caused by inadequate nitrogen fertilization reduced the percentage of fertile stalks, spikelet fertility and grain mass. Silicon fertilization reduced the number of blank spikelets per panicles and increased grain mass, but did not affect grain productivity.O silício não é considerado um elemento essencial para o crescimento e desenvolvimento das plantas, entretanto, sua absorção traz inúmeros benefícios, principalmente ao arroz, como aumento da espessura da parede celular, conferindo resistência mecânica a penetração de fungos, melhora o ângulo de abertura das folhas tornando-as mais eretas, diminuindo o auto-sombreamento e aumentando a resistência ao acamamento, especialmente sob altas doses de nitrogênio. O presente trabalho teve por objetivo avaliar os efeitos da adubação nitrogenada e silicatada nos componentes vegetativos, nos componentes da produção, na altura da planta e na produtividade da cultivar de arroz IAC 202. O experimento foi constituído da combinação de três doses de nitrogênio (5, 75 e 150 mg de N kg-1 de solo) aplicado na forma de uréia e quatro doses de silício (0, 200, 400 e 600 mg de SiO2 kg-1 de solo), aplicado na forma de silicato de cálcio. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 3 ´ 4 (N = 5). A adubação nitrogenada aumentou o número de colmos e panículas por metro quadrado e o número total de espiguetas, refletindo na produtividade de grãos. O perfilhamento excessivo causado pela adubação nitrogenada inadequada causou redução na porcentagem de colmos férteis, na fertilidade das espiguetas e da massa de grãos. A adubação silicatada reduziu o número de espiguetas chochas por panícula e aumentou a massa de grãos sem, contudo, refletir na produtividade de grãos.

Este trabalho foi desenvolvido em um solo contaminado por metais pesados de uma área de extração e industrialização de zinco pertencente à Companhia Mineira de Metais, em Três Marias, MG, com o objetivo de avaliar a eficiência do silício e do fósforo como agentes amenizadores da toxidez dos metais pesados. As amostras coletadas foram preparadas e incubadas em frascos de polietileno, com umidade equivalente a 60% do volume total de poros. Foram utilizados 25 tratamentos: cinco doses de silício (0; 2.340; 6.040; 9.860 e 13.660 mg dm-3) e cinco de fósforo (0; 90; 180; 360 e 720 mg dm-3), com quatro repetições, totalizando 100 unidades experimentais. Aos 30 e 60 dias, coletaram-se amostras de cada tratamento, submetidas a análises de pH em água e extrações simples por Mehlich-1. Os teores extraídos receberam influência do silício, do fósforo e do pH. Os teores de Zn e Cd, embora reduzidos, permaneceram acima dos níveis permitidos. O Pb diminuiu influenciado pelo incremento de silício e fósforo a níveis inferiores aos permitidos.This work was developed on a soil contaminated by heavy metals from a zinc-extracting and industrializing area belonging to the Companhia Mineira de Metais at Tres Marias, Minas Gerais state, Brazil, with a view to evaluating the efficiency of silicon and phosphorus as ameliorating agents of heavy metal toxicity. The samples collected were prepared and incubated into polyethylene flasks, moisture equivalent to 60% of the total volume of pores. 25 treatments were utilized: five doses of silicon (0; 2.340; 6.040; 9.860 and 13.660 mg dm-3) and five of phosphorus (0; 90; 180; 360 and 720 mg dm-3) with four replicates amounting to 100 experimental units. At 30 and 60 days, samples from each treatment were collected, submitted to water pH analysis and simple extraction by Mehlich-1. The extracted contents received greater influence from both silicon and phosphorous and at a lesser extent from pH. Zn and Cd contents, although reduced, remained above the allowed levels. Pb decreased, influenced by the increase of silicon and phosphorus to level inferior to those permitted.

Objective: To evaluate inflammatory reaction, fibrosis and neovascularization in dural repairs in Wistar rats using four techniques: simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Methods: Thirty Wistar rats were randomized in five groups: the first was the control group, submitted to dural tear only. The others underwent durotomy and simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Animals were euthanized and the spine was submitted to histological evaluation with a score system (ranging from zero to 3) for inflammation, neovascularization and fibrosis. Results: Fibrosis was significantly different between simple suture and silicon mesh (p=0.005) and between simple suture and mesh with suture (p=0.015), showing that fibrosis is more intense when a foreign body is used in the repair. Bovine membrane was significantly different from mesh plus suture (p=0.011) regarding vascularization. Inflammation was significantly different between simple suture and bovine collagen membrane. Conclusion: Silicon mesh, compared to other commercial products available, is a possible alternative for dural repair. More studies are necessary to confirm these findings. [ABSTRACT FROM AUTHOR]