399 resultados para Ciencias agrarias


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An experiment was carried out during the period of January to July/2010, in municipality of Areia, Paraiba State, Brazil, in order to evaluate effects of the irrigation with saline water, bovine biofertilizer and drainage of the soil on water consumption and growth of neem seedlings. The experimental design was in randomized blocks using factorial 5×2×2, referring to five levels of saline water (0.5; 1.5; 3.0; 4.5; 6.0 dS nr-1) in soil without and with bovine biofertilizer and in pots without and with drainage. In plants the water consumption, growth in height, stem diameter, number of leaves, dry matter of roots, aerial part and total dry mass were evaluated and in soil the electrical conductivity of saturation extract - EC was determined. The bovine biofertilizer, after dilution in non saline water (0.49 dS nr-1) e no chlorinated water in 1:1 ratio was applied once two days before sowing, equivalent to 10% of substrate volume. Irrigation was applied daily with each water type applying volume sufficient to maintain the soil with water content at level of field capacity. From results the increase in salinity of water inhibited the water consumption by plants independently of the soil with or without bovine biofertilizer. The salinity of water in soil with and without bovine biofertilizer also reduced the growth of neem plants but with more pronounced effect in the treatments without application of organic fertilizer to soil in liquid form.

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The crop of soursop has been known for presenting great potential for the domestic market and good prospects for export. In this context, an experiment was conducted in the municipality of Remigio in the state of Paraiba, in order to evaluate the effects of irrigation depths applied weekly on the productive behavior and postharvest quality of fruits of soursop 'Morada' in the soil with and without mulching with crop residues. Treatments were arranged in randomized blocks with three replications and three plants per plot, using a factorial arrangement 5×2, referring to the soil with and without mulching with crop residues, and five irrigation depths of 0, 4.3, 8.6, 12.9 and 17.2 mm plant1. Irrigation was performed manually, once a week from September 2008 to March 2009. The presence of mulch on the soil and increasing depths of irrigation elevated the values of mean mass, production per plant and yield of soursop 'Morada', and decreased the levels of soluble solids.

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The aim of this study was to evaluate the biocampatibility of the commercial nylon band used as bone cerclage, comparing with traditional metal cerclage wires. Twenty one rabbits and fifteen rats, healthy and without orthopedics problems were used. A commercial nylon band and a surgical stainless steel wire 0 were used in right (SN) and left (SA) rabbits's hindlimb, respectively. Otherwise, on rats SN was on the left hindlimb, and SA on the right hindlimb. Both experimental species were divided into three groups according to the end of the evaluation period. Clinical, radiographic, macroscopic and histologically evaluation were performed at 30, 60 and 150 days postoperatively. All the animals showed normal limb function differences between groups were not observed at clinical and macroscopic evaluation. On both species, radiographic changes were slightly higher on SN. Histological differences were not observed in both species. Nylon bands do not cause foreign body reaction and other histological changes in rabbits and rats.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A serial of factors related to development of glyphosate-tolerant corn should be approached and best studied. This work was developed to evaluate foliar levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn, besides the grain yield of glyphosate-tolerant corn (DKB390 RR hybrid). An experiment was carried out under field conditions, during the crop year of 2010/2011. A randomized complete block design with four repetitions was used to distribute the treatments in the field. Twelve herbicide treatments were studied: glyphosate (720, 1200 and sequential application of 960 plus 720 g ha(-1) of the acid glyphosate equivalent), atrazine (2500 g ha(-1)), nicosulfuron (60 g ha(-1)), mesotrione (192 g ha(-1)), tembotrione (100,8 g ha(-1)), atrazine plus glyphosate (1000 + 960 g ha(-1)), atrazine plus nicosulfuron (1000 + 20 g ha(-1)), atrazine plus mesotrione (1000 + 144 g ha(-1)) and atrazine plus tembotrione (1000 + 75,6 g ha(-1)) and one control treatment without herbicide. The glyphosate and mesotrione alone did not cause no visible injury to corn. The other herbicides caused intoxication symptoms classified as light (<5%). The treatments studied did not affect foliar levels of N, P, K, Ca, Mg, S, B, Mn and Zn in the corn plants. But, the plants treated with atrazine plus nicosulfuron had more leaf Fe content, and the plants sprayed with glyphosate (in the three doses) and atrazine, more accumulation of Cu in the leaf. The Grain yield of corn was reduced with application single of glyphosate (1200 g ha(-1)), nicosulfuron, tembotrione and with the mixture atrazine plus nicosulfuron.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In Brazil, phosphorus availability is one factor that that more limit yield of upland rice under rainfed system. Then, better understanding of cultivars development at phosphorus soil fertilization is very important in the production systems making this more sustainable. The objective was to evaluate the influence of phosphorus doses applied to the soil over the root length, root and shoot dry matter, concentration and content of macronutrient and zinc in shoot and root as well as the efficiency of nutrient uptake per meter root of upland cultivars of intermediate and modern groups. The experiment was carried out in greenhouse conditions in a completely randomized design in factorial scheme 4 x 4. Treatments were four levels of P fertilization applied at the soil (0, 50, 100 and 200 mg dm(-3) of P) and four upland rice cultivars (Maravilha - modern group, IAC-201, IAC-202 and Carajas - intermediate group). There is increase in phosphorus availability in the soil with increasing levels of P fertilization. Under low phosphorus availability, cultivars of the intermediate group have better shoots and root system development in relation to the modern cultivar group. Level of phosphorus affected nutrients contents in shoots and root system of upland rice cultivars. The increasing phosphorus fertilization increased uptake of nutrients per meter of root; and although under higher phosphorus availability there was a greater root growth, in low phosphorus availability root growth was greater at the expense of shoot growth.

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The infestation of weeds is a major biotic factor in the agroecosystem of cane sugar that may interfere in development and crop productivity. This study aimed to evaluate the potential for leaching and residual effects of the herbicide amicarbazone in contrasting soils. Samples were Quartzarenic Neosol (NR - sandy texture) and Red Latosol (LR - clay texture). For the leaching potential, after application of herbicide amicarbazone (NR 1.05 kg ha(-1) and LR 1.40 kg ha(-1)), layers of 0, 20, 40, 60, 80 and 100 mm of water were applied to soil columns. We evaluated the residual effect after the permanence of the herbicide in soil of clay texture and sandy for periods of 0, 25, 50, 75 and 100 days after application (DAA) of amicarbazone (0, 1.05, 1.40 kg ha(-1)) treatments. The amicarbazone started showing high leaching from the 60 mm layer of water in sandy texture soils, evidencing a shorter residual effect. In clay soil, slides from 20 to 80 mm of water reduced the biomass until a depth of 5-10 cm, with the use of this herbicide. Based on these results, we conclude that the amicarbazone showed higher leaching and lower residual effects in sandy soil. The residual effect of amicarbazone was prolonged as the content of clay and organic matter present in the soil increased.

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In clayey Oxisol from the Brazilian Cerrado, where there is high P fixation, the phosphorus fertilization is necessary to increase the growth and flowering of ornamental plants. Thus, the objective of this study was to analyze the development of Hemerocallis as affected by phosphorus application in clayey Oxisol (Typic Haplustox). The experiment was conducted at the Gardening area of University Federal of Grande Dourados (UFGD) in Dourados-MS, Brazil. The experimental design was a randomized block with four replications. The treatments consisted of four P2O5 rates (0, 250, 500, 1000 kg ha(-1)) using simple superphosphate as source. The experimental unit was composed of one Hemerocallis fulva 'Flore Pleno' plant, grown in a plastic pot (5 liters). Phosphorus fertilization increased linearly the concentration of phosphorus in the soil; the plant had maximum absorption (5.26 g kg(-1)) with the calculated dose of 727 kg ha(-1) P2O5. H. fulva has a root system that develops best under high availability of P, however, for aerial part, the maximum of shoots fresh mass (451.1 g) was obtained with 427 kg ha(-1) of P2O5. Number of flower buds, flower diameter and height flower stalks were higher in the presence of phosphorus.

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Inulin and oligofructose are fructans that can change important characteristics in original products when added in food. Two formulations of orange cakes (one containing 77.7g of inulin and another one 77.7g of oligofructose/inulin) and two formulations of breads (one containing 130g of inulin and another one 175g of oligofructose/inulin) were compared to the respective standard formulations (with no fructans) in relation to chemical composition, texture, volume, color and sensory acceptability with a nine-point hedonic scale. The cakes and breads with inulin and oligofructose/inulin showed greater amount of total dietary fiber in relation to standard products. The orange cake with inulin had lower cohesiveness and yellower dough when compared to the standard cake, but the addition of inulin and oligofructose/inulin reduced the acceptability for appearance, texture and flavor and the overall acceptability, although the acceptability for aroma was the same for the three products. The breads with inulin and oligofructose/inulin were harder and less cohesive than the standard bread, and bread with inulin showed minor volume in relation to the standard. The bread with inulin also presented crust with lower luminosity, dough with higher intensity of redness and yellowness and higher intensity of color in relation to standard, besides different hue. In relation to sensory acceptability, the bread with oligofructose/inulin had higher overall acceptability and flavor when compared to standard bread.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The study of organic matter and its compartments and their relationship with management, aims to develop strategies for increasing their levels in soils and better understanding of its dynamics. This work aimed to evaluate the fractions of soil organic matter and their carbon stocks in different soil cover system in crop-livestock integration and native Cerrado vegetation. The study was conducted at the farm Cabeceira, Maracaju-MS, sample area have the following history: soybean/corn + brachiaria/cotton/oat + pasture/soybean/formation of pasture/grazing, sampling was carried out in two seasons, dry (May/2009) and rainy (March 2010), in the dry season, crops present were: pasture, corn and cotton + brachiaria and in the rainy season were corn, cotton and soybeans, so the areas in the two evaluation periods were: pasture / maize + brachiaria / cotton, cotton / soybean area and a native of Savanna. Was performed to determine the exchangeable cations, particle size analysis, bulk density, organic carbon, particle size fractionation of organic matter of the soil with the quantification of particulate organic carbon (POC) and organic carbon associated with minerals (OCam). Was also quantified the carbon stock and size fractions. The area of pasture / maize showed higher carbon stock in the particulate fraction in the topsoil. The area of cotton / soy due to its lower clay, showed the greatest loss of carbon. Because of the areas have the same history, the stock of more recalcitrant fraction was not sensitive to variations in coverage. The POC fraction appears more sensitive to different soil covers and seasonality.

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The correct spatial intervention in the administration of the plantation, arising from specific areas of soil mapping, can increase your productivity as well as profitability and yields in agriculture. The spatial and Pearson's relationships between sugarcane attributes and chemical attributes of a Typic Tropustalf were studied in the growing season of 2010, in Suzanapolis, State of Sao Paulo, Brazil (20 degrees 27'33 '' S lat.; 51 degrees 08'05 '' W long.), in order to obtain the attributes that had the best sugarcane productivity relationship. To this end, a geostatistical grid containing 118 sample points was installed for soil and plant data collection in an area of 10.5 ha with the third crop cut. The productivity of sugarcane (PRO) represented the attribute of the plant, while the attributes of the soil were: K+, Ca+2, Mg+2 and organic matter at depths of 0-0.20 m and 0.20-0.40 m. Relationships were calculated between the PRO and the attributes of the soil. Semivariograms were adjusted for all attributes, obtaining the respective krigings and the cross-validations. It was also made the cokrigings between the PRO and the soil attributes. The levels of the soil organic matter, for their evident substantial correlations, Sperman's Rho and spatial, with the productivity of sugarcane, are indicators of two specific areas of soil management strongly associated with the productivity of sugarcane. In such zones this productivity varies between 75.8-94.7 t ha(-1) and 101.0-119.9 t ha(-1), when the levels of organic matter respectively are 12.7-14.5 g dm(-3) (0-0.20 m) and 11.8-12.8 g dm(-3) (0.20-0.40 m).

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Studies related cryptosporidiosis will be essential, due to its relevance in public health and pathogenicity in pets and production animals. Over the past 20 years, there has been a rapid expansion of research involving the Cryptosporidium genus, largely related to molecular studies, providing a description of various species, genotypes and subtypes of the parasite. The molecular characterization of isolates from different sources (human, animal and environmental) has been widely used in order to investigate the potential zoonotic of this protozoa. The documented transmission forms from animals to humans, from person to person, through water intake or water for the leisure that are directly or indirectly contaminated with sporulated oocysts. The high rate of animals naturally infected and the susceptibility by protozoan, justify the importance of attending to the occurrence of this disease. So are demonstrated epidemiological aspects of this zoonotic disease in domestic animals.

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The goal of this study was to evaluate the concentrations of non-structural carbohydrate (NSC) and of total nitrogen (N), as well as, to evaluate the root system in Tanzania-grass pastures fertilized with doses of urea in fall, spring and summer. The experiment was conducted at the Experimental Farm of Iguatemi, Maringa, Parana, Brazil, from March 2007 to March 2008. The experimental design was complete random blocks with subplots and four repetitions. The plots showed doses of N (50, 100 e 150 kg ha(-1) of N) plus the control (no N fertilization), and the subplots the season of the year. Root samples were taken at depths of 0-10, 10-20 and 20-40 cm. Root biomass showed a trend for mass accumulation up to a dosage of 100 kg ha(-1) for all seasons evaluated. Also, about 80% of the root system of Tanzaniagrass plants was found on the 0-10 cm layer for all dosages of N. Nitrogen fertilizer above 100 kg ha(-1) may foster fast forage plant growth reducing its NSC root storage capacity although favoring NSC and total N storage at stem base. NSC and total N concentrations were highest in fall, demonstrating that its usage is greater in spring due to the weather conditions being favorable to plant growth. In the regrowth, the largest reserve of total N was at the 0-10 cm root layer and the largest NSC reserve is at stem base.