491 resultados para vegetative tiller


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Intending to achieve better results on coffee production, the coffee producers began, since the 80s, to process the coffee postharvest, in order to ensure product's superior quality. However, with the processing, other problem appeared, the contamination of rivers, creeks, soil and water table from coffee wastewater (ARC). This paper had as main objective to use the ARC on the coffee plants' production verifying its viability and if the ARC is able to supply the coffee potassium requirements when they don't receive potassium chloride in the organic compound. The work was developed at Faculdade de Ciências Agronômicas - UNESP, Botucatu-SP, in a greenhouse located at Departamento de Engenharia Rural. The work consisted of 10 treatments on a 5×2 factorial (5 wastewater proportions of coffee after the harvest processing - 0%, 25%, 50%, 75% and 100% - and potassium chloride presence or absence in the composition), with 4 repetitions with a completely randomized statistical design. The ARC was applied each 48 hours in an irrigation depth of 10 mm. After 6 months, the plants' vegetative characteristic had been evaluated as well the chemical characteristics of the compound and of the plants. We observed that the treatments with potassium chloride presence showed worse vegetative characteristics compared with treatments which did not have KCl in its composition. Moreover, with the increase of the wastewater dosage, it happened a decrease in the vegetative characteristics, however an addition in the chemical characteristics of the compound. Also, the treatments without KCl presence and with 0% and 25% of coffee wastewater had been statistically equal, showing the viability in the use of the ARC in the production of coffee plants, since the compound does not contain KCl and that the water used in the composition is a mixture of 25% of ARC with 75% of common water.

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Eucalyptus urophylla S. T. Blake is outstanding for valuable wood production potential, adaptation plasticity for different environmental conditions, and for tolerance to canker. However, genetic improvement of this specie in Brazil depends on the existence of genetic variability in the introduced populations. The objective of this study was to investigate the genetic variation and gains in quantitative traits in a population established in 1992 in Selvíria - MS. The progeny trial was established in a partially balanced, 8 x 8 lattice design, with 64 families, collected at Anhembi Experimental Station (IPEF/ESALQ/USP). Each plot was made up of eight trees planted in a 3 × 3 m spacing. Significant among families genetic variations were observed in diameter at breast height (DBH), bark type, stem form, and survival. Estimates of average family heritability were high for all traits, ranging from 0.50 to 0.85. The simulated selection by using multi-effect index showed that under a varying number of plants per family. This method is the most indicated to maximize genetic gains (7.24%) and the effective population size (69.3). These results are a useful support for the transformation of this test into a seedling seed orchard and to become a source of vegetative material to build a clonal seed orchard.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The analysis of both morphogenetic and structural characteristics of pasture allows us to understand the response patterns of the plant to the environment. Thus, this study was conducted to evaluate the associations between the morphogenetic and structural characteristics of Brachiaria decumbens under continuous grazing by cattle. The development of individual tillers in pastures was evaluated under two grazing management strategies during three seasons (winter, spring and summer). Pearson correlations between variables were estimated. The lengths of leaf and stem, number of tillers and leaves per tiller, rates of leaf appearance and elongation of leaf and stem of B. decumbens were positively correlated. There was a negative relationship between appearance and lifespan of leaves (r = -0.89). However, positive correlations between leaf appearance rate and number of tillers (r = 0.64) and between length of stem and leaf senescence rate (r = 0.63) were determined. The B. decumbens modifies its morphogenesis to better adapt to climate and grazing management.

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The present assay was conducted at the Research and Development of Adamantina, SP, of the Agência Paulista de Tecnologia dos Agronegócios (APTA) - Pólo da Alta Paulista to evaluate the effect of nitrogen fertilization on morphological composition, density of tillers, leaf area index, light interception and herbage accumulation in grazed Tifton 85 subjected to continuous stocking system. The treatments consisted of four levels of nitrogen (0; 100; 200 and 400kg/ha/year of N), arranged in a randomized complete blocks experimental design with four replications. The grasslands of Cynodon cv. Tifton 85 studied influenced the time of evaluation and of nitrogen levels with a marked effect in morphological composition of the pasture, leaf area index, light interception and population density of tillers that were instrumental in the accumulation of forage. It was found a positive linear effect of nitrogen fertilization on the density of vegetative tillers, totals and herbage accumulation nitrogen fertilization had a marked effect on the amount of total and vegetative tillers, leaf area index in light interception and herbage accumulation. The cultivar Tifton 85 has not reached the necessary conditions for crop growth rate maximum when managed under continuous stocking keeping the grass to 10cm tall.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The amount and timing of nitrogen application can favor seed quality, such as increasing protein content, which is an important constituent for embryo development. The objective of this study was to evaluate the physiological quality of sweet corn seeds collected from plants cultivated with different dosages and timings of nitrogen top-dressing applications. Seeds of the BR 400 variety (Super Sweet) were used obtained from plants submitted to dosages of 0, 40, 80 and 120kg ha -1 of N in two top-dressing applications (vegetative and reproductive stages). The weight of 100 grains, germination, first count of germination test, dry weight of normal seedlings from the germination test, seedling growth, cold test, accelerated aging, tetrazolium vigor and electric conductivity and emergency speed rate were determined. Data was submitted to an analysis of variance using the F-test at the 5% level and second degree regression analysis. The dosage and time of application of nitrogen top-dressing did not affect seed weight or the germination of sweet corn seeds. An increase of the N top-dressing dosage, applied in the vegetative stage reduced the length of the aerial part, the root and the whole seedling.

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Tillers survival and yield potential are genetically determined and strongly influenced by environmental conditions during the emission and establishment stage. This experiment was carried in order to study effects of application of growth regulator (Ax+GA+CK) on tiller survival and yield potential of wheat. The experiment was carried out from March to July 2010. A 2 × 2 factorial randomized block design with five replications was used. Two wheat cultivars (IAC 370 and IAC 375) and application or not of Ax+GA+CK at the beginning of tillering stage were evaluated. Tiller emission were evaluated at five ages (19, 26, 33, 40 e 47 days after emergence) and yield components were determined by each individual structure evaluation, comparing to the main stem. Growth regulator application improved the tiller survival when emitted in the first week after application. Tiller yield potential decreased in late emission periods of tillers in both cultivars tested, influenced by different traits of each cultivar. IAC 370 showed higher tiller emission, however, the number of viable tillers were higher for the IAC 375.

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Common Bean (Phaseolus vulgaris L.) is widespread in the social and economic scene in Brazil, as well it is Brazilian population main dish, and it also helps small and medium farmers' income. The objective of this study was to compare the productivity performance of common bean Carioca - IAC Alvorada with irrigation suppression in each of the five phenological phases. The experiment was conducted in plots in a greenhouse at College of Agronomical Sciences, São Paulo State University (UNESP), Botucatu - SP. The hypothesis is that if the water supply is suppressed in one of the five development stages of irrigated common beans, the yield reduction would be at least 20%. The treatments consisted of suppression irrigation in one of the five development stages (stage V1 to V3, stage V4 to early flowering, flowering stage, pod formation stage and pod filling stage) compared with the irrigation at all stages and suppression of irrigation at all stages, with seven treatments and four replications. The treatments most affected by water suppression were those which suffered suppression of irrigation during the vegetative phase and flowering stage. Treatments with water suppression in all stages, and suppression during the phases (stage V1 to V3, stage V4 to early flowering, flowering stage, pod formation stage and pod filling stage) showed yield reduction of approximately 95%, 55.1%, 49.5%, 63,1%, 30.2% and 35.6%, respectively, when compared to treatment with irrigation all stages. All treatments considered confirmed the hypothesis.

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The study of growth and uptake of nutrients is important to determine the times of increased demand in order to schedule the fertigation. The present research was developed with the objective of evaluating the effects of different levels of electrical conductivity on growth and accumulation of nutrients in chrysanthemum plants under greenhouse conditions. The electrical conductivity levels on the applied solution were 1.42, 1.65, 1.89, 2.13 and 2.36 dS m-1 (bud vegetative stage); 1.71, 1.97, 2.28, 2.57 and 2.85 dS m-1 (bud stage). The dry mass of the aerial portion of the plant and the contents of macronutrients and micronutrients were determined every 14 days. The nutrient accumulation in chrysanthemum plant showed similar trend as compared to dry matter accumulation. The nutrients presented the following order of absorption: K>N>Ca>Mg>P>S (1425, 892, 184, 150, 110 and 59 mg plant-1) and Fe>Zn>B>Mn>Cu (2254, 2219, 1725, 1287, 210 μg plant-1). The content of most nutrients increased with increase in electrical conductivity of the solution, without salt effect up to EC of 2.85 dS m-1.

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This work aimed to study the intercropping of corn and Urochloa ruziziensis cv. Common, regarding to vegetative growth and corn yield, capacity of production of forage dry matter, the infestation of weeds and the effect of this system of production in the soybean crop in rotation. Two forms of sowing (hand-sowing and on-line sowing) of U. ruziziensis, four amounts of seeds (200, 400, 600 e 800 points of cultural value, PCV = quantities of seeds x cultural value) and one treatment additional with the single corn were studied. The intercropping did not affect negatively the vegetative growth and corn yield when compared to the single corn. The sowing of 200 PCV of U. ruziziensis seeds, hand-sowed and on-line sowed to 22 days after of sowing of the corn was enough for the maintenance of adequate amount of straw on the soil. At the moment of the harvest of the corn, the dry matter of weed reduced with the increase of the amount of U. ruziziensis seeds and was bigger when the forager was hand-sowed. In the soybean crop in rotation, the density and dry matter of weed reduced linearly with the increase of the amount of U. ruziziensis seeds used in the first year of the research. The intercropping of corn and U. ruziziensis in the first year of the experiment benefited the plants population, plants height and yield of soybean when compared to the monoculture of corn in the same period.

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Iron (Fe) is essential for chlorophyll formation and plant growth. Irondeficiency chlorosis is a major nutritional disorder in several fruit trees cultivated in calcareous and alkaline soils, reducing fruit yield and quality and causing heavy economic losses. Since chelated Fe, the most widespread fertilizers used for preventing or curing Fe deficiency, pose risks of environmental pollution, the development of sustainable agronomic alternatives represents a priority for the fruit industry. In this work, we investigated the effectiveness of a bovine blood-derived product (BB; 0,125% Fe) for preventing Fe-deficiency in grapevine plants. During the vegetative season 2011 potted plants of five graft combinations: Sangiovese/S4O, Cabernet Sauvignon/S4O and Cabernet Sauvignon/140 Ruggeri, 140 Ruggeri/Cabernet Sauvignon, Vitis riparia/Cabernet Sauvignon were grown on calcareous soil. Soil treatments included: 1) Control; 2) Fe-EDDHA (Fe 6%); 3) Bovine-Blood (5 g/L); 4) Bovine-Blood (20 g/L). With the exception of Cabernet Sauvignon/S4O plants, Fe-EDDHA increased SPAD units (leaf chlorophyll content). Bovine-blood at low concentrations had similar or higher SPAD units than Fe-EDDHA. Increasing concentration resulted in further increases in SPAD units only in some graft combinations. Data highlight the efficiency of Fe blood-compound in the prevention of grapevine Fe-deficiency over one growing season.

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Axillary bud outgrowth determines shoot architecture and is under the control of endogenous hormones and a fine-tuned gene-expression network, which probably includes small RNAs (sRNAs). Although it is well known that sRNAs act broadly in plant development, our understanding about their roles in vegetative bud outgrowth remains limited. Moreover, the expression profiles of microRNAs (miRNAs) and their targets within axillary buds are largely unknown. Here, we employed sRNA next-generation sequencing as well as computational and gene-expression analysis to identify and quantify sRNAs and their targets in vegetative axillary buds of the biofuel crop sugarcane (Saccharum spp.). Computational analysis allowed the identification of 26 conserved miRNA families and two putative novel miRNAs, as well as a number of trans-acting small interfering RNAs. sRNAs associated with transposable elements and protein-encoding genes were similarly represented in both inactive and developing bud libraries. Conversely, sequencing and quantitative reverse transcription-PCR results revealed that specific miRNAs were differentially expressed in developing buds, and some correlated negatively with the expression of their targets at specific stages of axillary bud development. For instance, the expression patterns of miR159 and its target GAMYB suggested that they may play roles in regulating abscisic acid-signalling pathways during sugarcane bud outgrowth. Our work reveals, for the first time, differences in the composition and expression profiles of diverse sRNAs and targets between inactive and developing vegetative buds that, together with the endogenous balance of specific hormones, may be important in regulating axillary bud outgrowth. © 2013 © The Author(2) [2013].

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Defaunation, the loss or population decline of medium and large native vertebrates represents a significant threat to the biodiversity of tropical ecosystems. Here we review the anthropogenic drivers of defaunation, provide a brief historical account of the development of this field, and analyze the types of biological consequences of this impact on the structure and functioning of tropical ecosystems. We identify how defaunation, operating at a variety of scales, from the plot to the global level, affects biological systems along a gradient of processes ranging from plant physiology (vegetative and reproductive performance) and animal behavior (movement, foraging and dietary patterns) in the immediate term; to plant population and community dynamics and structure leading to disruptions of ecosystem functioning (and thus degrading environmental services) in the short to medium term; to evolutionary changes (phenotypic changes and population genetic structure) in the long-term. We present such a synthesis as a preamble to a series of papers that provide a compilation of our current understanding of the impact and consequences of tropical defaunation. We close by identifying some of the most urgent needs and perspectives that warrant further study to improve our understanding of this field, as we confront the challenges of living in a defaunated world. © 2013 Elsevier Ltd.