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Mendes A.D.R.,Federal University of Minas Gerais | de Oliveira L.E.M.,Federal University of Lavras | do Nascimento M.N.,State University of Feira de Santana | Reis K.L.,University of Sao Paulo | Bonome L.T.S.,University Federal da Fronteira do Sul
Acta Amazonica | Year: 2012

The Rubber tree during its adult phase presents intermittent growth within the leaf exchange process characterized by senescence, which is a nutrient-recycling mechanism used by trees through biochemical and biogeochemical cycles. Studies including biochemical cycles are necessary in order to verify the mineral nutrients' dynamics at different leaf stages. The conservation of such nutrients is very important to optimize the growing conditions for rubber plantations which are located in soils with low fertility. This study aims to evaluate the mineral nutrients' dynamics during different leaf stages of the rubber tree, leaves were collected from the clones of RRIM-600 taken from a rubber tree plantation in Nepomuceno County, State of Minas Gerais, Brazil. Eight adult examples with leaves in different stages: B1, B2, C and D, plus senescent leaves (Sen) were selected for the study. Samples from leaves in stages B1, B2, C and D were taken from the trees at the four orthogonal points; the senescent leaves were collected from the ground after mechanically shaking the branches. The study revealed a decrease in the level of N, P, K, S, Cu and Zn during the development of the rubber tree's leaf. In contrast, during the same period the levels of Ca, Mg, B, Fe and Mn increased. The redistribution for N, P, K and Cu was higher and the relative order of macronutrient and micronutrient levels in the leaves were respectively: N>K>Ca>Mg≥S>P and Mn>Fe>Zn>B>Cu. Source

de Barros M.M.,Federal Rural University of Rio de Janeiro | Volpato C.E.S.,Federal University of Lavras | Silva F.C.,Federal University of Fluminense | Palma M.A.Z.,University Federal da Fronteira do Sul | Spagnolo R.T.,Federal University of Pelotas
Coffee Science | Year: 2015

An extremely important factor in the production of coffee and other crops is the distribution of fertilizers on the soil, because the efficient use of this technique may increase productivity, reduces production costs and environmental impacts. Precision Agriculture is an important tool to be used, that aids the achievement of localized and rational application of fertilizers, increasing the management activities. The aim of this research was to evaluate the operational performance of a fertilizer application system at variable rate and to create evaluation parameters for coffee crop. Three types of tests were performed: The Cross-Deposition Test, in order to determine the machine’s maximum distribution range and to observe the effects of speed and doses changes; The Longitudinal Deposition Test, in order to determine the machine’s distribution characteristics along the displacement line, and analyze the application behavior on both sides of distribution; The Work Regime Test in order to check the distribution behavior of the machine in real field conditions. We observed that the variation of doses and speeds haven’t affected the precision of the distribution system. There was variation at the system’s application between right and left sides. The system application at variable rate in real field conditions showed a mean error of -3.31%. Therefore, the methodology used is possible to evaluate the variables present in the fertilizers application in coffee production. © 2015, Editora UFLA. All rights reserved. Source

Correa V.G.,University Federal da Fronteira do Sul | Tureck C.,University Federal da Fronteira do Sul | Locateli G.,University Federal da Fronteira do Sul | Peralta R.M.,State University of Maringa | Koehnlein E.A.,University Federal da Fronteira do Sul
Revista de Nutricao | Year: 2015

Objective Estimate the intake of phenolic compounds by the Brazilian population. Methods To estimate the average per capita food consumption, micro data from the National Dietary Survey and from the Household Budget Survey from 2008 to 2009 was analyzed. The phenolic content in food was estimated from the base of Phenol-Explorer. It was chosen according to compatibility and variety of food items and usual method of preparation. Results The Brazilian population consumed, on average, 460.15 mg/day of total phenolic compounds, derived mainly from beverages (48.9%), especially coffee and legumes (19.5%). Since this analysis of classes of phenolics it was possible to observe an intake of 314 mg/day of phenolic acids, 138.92 mg/day of flavonoids and 7.16 mg/ day of other kinds of phenolics. Regarding the variables studied this present study shows that those men who live in the countryside and in the northeastern region of the country had a higher consumption of phenolic compounds. Besides, consumption was higher by adults and the elderly, the medium income classes, the population with incomplete and complete primary education and those with adequate nutrition and also overweight status. Conclusion The intake of phenolic compounds can be considered low, especially where consumption of fruit and vegetables is insufficient. We can conclude that coffee and black beans were the best contributors to phenolic intake. Source

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