44 resultados para semiarid
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O manejo de irrigação pode influenciar o comportamento ecofisiológico e a produção da videira. O objetivo desse trabalho, conduzido em 2010 em Petrolina – PE, no Submédio do Vale do São Francisco, foi avaliar a influência de diferentes estratégias de manejo de irrigação no potencial de água na folha e em aspectos qualitativos e quantitativos das uvas do primeiro ciclo de produção da videira cv. Syrah/Paulsen 1103. O sistema de irrigação utilizado foi gotejamento e a lâmina de água foi estimada com base na evapotranspiração da cultura. O delineamento experimental utilizado foi o de blocos casualizados, em 4 repetições e com 3 tratamentos: irrigação plena, realizada durante todo o ciclo de produção; a irrigação com déficit, onde a aplicação de água foi interrompida na fase fenológica de cacho fechado; e a irrigação com déficit controlado, onde a irrigação, também interrompida na fase de cacho fechado, foi eventualmente realizada após a interrupção, de acordo com o monitoramento da água no solo. A imposição de déficit hídrico às plantas favoreceu uma maior concentração de açúcares e a redução da acidez nos frutos, contribuindo para a melhoria da qualidade das uvas para vinificação.
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The experiment was developed based on the importance of the nutritional factor cunhã for large and small, animals and on the growth of this forage in typical soils of the semiarid region, generally with salinity from natural or anthropogenic action. The experiment was performed in vessels with a capacity of 5kg prepared in a protected environment with full sunshine in the Department of Technology and Social Sciences (DTCS) of UNEB Campus III in Juazeiro - BA. It evaluated the effect of seven different salt concentrations on increasing levels of irrigation water electrical conductivity - ECw (0, 2, 4, 6, 8, 10 and 12 dS/m), at room temperature. The analysis of culture were taken every seven days observing the number of leaves, stem diameter, plant, plant length and total chlorophyll content at 13; 20; 27; 34 and 40 days after the start of irrigation with saline. The contents of proline, the ratio aero part/Root (AP/Rt), the root length and water content were evaluated in the 40 th day after the onset of treatment. The results showed that the elevation of ECw affected all variables.
Chemical and biochemical characterization of guava and araçá fruits from different regions of Brazil
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Guava and araçá, species of the Psidium genus, are important options for Brazilian agribusiness, especially the former species, due to their fruit characteristics, such as appearance, taste and richness in minerals and phenolic compounds. These fruits can be consumed in natura or in several processed forms. The active germplasm bank is an important tool for genetic resource characterization and plant breeding studies. Sixty guava and ten araçá accessions of the Psidium active germplasm, sampled in 44 different Brazilian regions and grown at Embrapa Semiarid, were chemically and biochemically characterized in order to support breeding programs. The accessions were grown in a randomized block design, with two replications and three plants/plot. The sugar, proteins, soluble solids, titratable acidity, calcium, magnesium, iron and phosphorus contents were determined. Large variations were observed in the analyzed compounds, which could be attributed to the diversity of genotypes and also to the environmental conditions, which affect the plant metabolism. The high variability observed in most parameters of the accessions is an important factor for the improvement of these species. Most guava accessions showed higher titratable acidity and soluble solids than those found in commercial cultivars and, in araçá, these levels were even higher, which makes them promising for commercial exploitation. Moreover, fruits of the guava and araçá accessions present good sources of sugars and minerals. Special attention should be given to some guava and araçá accessions from Maranhão and Pernambuco States, respectively, which showed high levels for titratable acidity, soluble solids, SS/TA ratio, total soluble sugars, calcium, magnesium and iron, should be targets of breeding programs for new Psidium cultivars. © ISHS.
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Different procedures for the integrated method of diagnosis and recommendation may influence the accuracy of foliar diagnosis of mango. Thus, the objective of this study was to compare the diagnosis of nutritional status of mango obtained by different methods of assessing nutritional status, comparing multivariate relations (method CND) with bivariate relationships (DRIS) i.e., variations in the use of specific or preliminary standards and a logarithmic transformation of the data. The macro and micronutrient leaf analysis results of 63 mango orchards of Lower-middle São Francisco River Valley, Brazil, were used. To interpret nutritional status the Potential Response to Fertilization (PRA) criteria was used. The CND and DRIS methods, with and without logarithmic transformation and using specific or preliminary standards, which showed similar performance in assessing the nutritional status of the mango in Lower-middle San Francisco. Mango orchards in the semiarid region of northeast Brazil, the micronutrient deficiencies (Zn, Fe and Cu) were more frequent than macronutrient deficiency.
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Paclobutrazol applied to the soil is used for the production management of mango in most of orchards on the semiarid region. However, it is necessary to identify other plant growth regulators that might be applied to the leaves, so as to minimize the risk of residues in the soil and plant. The present paper has the purpose to evaluate the effect of plant regulators in the management of vegetative growth on mangoes 'Tommy Atkins'. Three plant growth regulators, sprayed to the leaves, were evaluated: prohexadione-Ca, ethyl-trinexapac and chlormequat chloride, applied in two dosages, and compared to paclobutrazol applied to the soil. In order to compare the effects of the treatment, data were recorded on the vegetative growth (number and length of the shoots). Furthermore, the levels of gibberellins in the apical area of the shoots of 'Tommy Atkins' were quantified, from the beginning of the experiment until the beginning of floral induction. The results showed that sprayings with prohexadione-Ca, trinexapac-ethyl and chlormequat chloride in a dosage of 1.5 g a.i. plant-1 plant was as efficient as a dose of 4.0 g a.i. plant-1 of paclobutrazol applied to the soil, regarding the regulation of vegetative growth of 'Tommy Atkins'. © ISHS 2013.
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A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit Tocantins Fossil Trees Natural Monument In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry seasons. Thick mudstones and some coquinites below and above the sandy interval may represent lacustrine facies formed in probably more humid conditions. The taphonomic history of the preserved plants began with exceptional storms that caused fast-flowing high water in channels and far into the floodplains. In the eastern site region, many tree ferns only fell, thus sometimes covering and protecting plant litter and leaves from further fragmentation. Assemblages of the central and western sites suggest that the trees were uprooted and transported in suspension (floating) parallel to the flow. Heavier ends of stems (according to their form or because of attached basal bulbous root mantle or large apical fronds) were oriented to upstream because of inertial forces. During falling water stage, the stems were stranded on riverbanks, usually maintaining the previous transport orientation, and were slightly buried. The perpendicular or oblique positions of some stems may have been caused by interference with other stems or shallow bars. Rare observed stems were apparently waterlogged before the final depositional process and transported as bedload. The differences of interpreted channel orientations between the three sites are expected in a braided fluvial system, considering the very low gradients of the basin and the work scale in the order of tens of kilometers. The mean direction of the drainage probably was to east and the flows apparently became weaker downstream. This study seems to provide reliable data for paleocurrent interpretations, especially considering areas with scarce preserved sedimentary structures. © 2013 Elsevier Ltd.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Ciência Florestal - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Pós-graduação em Ciências Biológicas (Botânica) - IBB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV