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Jacareí, Brazil

da Cunha A.C.M.C.M.,Instituto Federal Of Educacao Ciencia E Tecnologia Do Sudeste Of Minas Gerais | de Oliveira M.L.,Fibria Celulose | Caballero E.C.,University of Cordoba, Colombia | Martinez H.E.P.,Federal University of Vicosa | And 2 more authors.
Revista Ceres | Year: 2012

In recent years, the application of silicon (Si) in crops, including coffee, has become a common practice. The objective of this study was to assess the silicon uptake by coffee seedlings and its effects on plant growth, water and macro and micronutrient uptake. The research was conducted using nutrient solution in a greenhouse at the Departamento de Fitotecnia da Universidade Federal de Viçosa, in a completely randomized design with two treatments (with and without silicon) and three replications. Each plot consisted of three plants grown in a 800 mL vessel containing the treatment solutions. At every three days, water consumption, the concentration of OH - and the depletion of Si and K were assessed in the nutrient solutions. After 33 days, the plants were assessed with regard to their fresh and dry weight of leaves, roots and stem, shoot height and total length of the plant (shoot and root). Number of leaves and internodes, and the content and accumulation of silicon, macro, and micronutrients were also determined. The consumption of water, the amount of potassium uptake and, biomass accumulation were greater in plants grown in solution without silicon addition. However, the concentration of OH- in the solution and the amount of silicon uptake were greater in plants grown in solution with added silicon. Silicon accumulation was greater in leaves than in stem and roots. Silicon decreased coffee plant accumulation of phosphorus, potassium, calcium, zinc, copper and iron. Source


Teodoro M.G.,Federal University of Vicosa | Ferreira M.A.,Federal University of Lavras | Guimaraes L.M.S.,Federal University of Vicosa | Mafia R.G.,Fibria Celulose | And 3 more authors.
Phytopathologia Mediterranea | Year: 2012

Leaf blight and defoliation caused by Teratospltaeria species is one of the most important leaf diseases of Eucalyptus globulus. Due to the importance of this tree species for the production of pulp and paper, and recent reports of severe leaf disease symptoms in Brazil, the present study was conducted to identify the pathogen(s) involved. Symptomatic leaves were collected in the Brazilian states of Parani and Rio Grande do Sul, single as-cospore cultures established, and isolates were investigated using DNA-based molecular tools. A species-specific PCR and sequence data from the nuclear ribosomal DNA operon were used for species identification. The following seven species were identified: Mycospltaerella scytalidii, Dissoconium dekkeri (=M. lateralis), Teratospltaeria olmowa, T. perpendicularis, T. pseudafricana, T. flexuosa and T.tiubilosa. Of the recorded species, T. nubilosa is regarded as the most serious threat to the cultivation of E. globulus in the states surveyed. © Firenze University Press. Source


Bezerra A.F.,Fibria Celulose | Milagres F.R.,Federal University of Vicosa | da Silva M.L.,Federal University of Vicosa | Leite H.G.,Federal University of Vicosa
Cerne | Year: 2011

The objective of this study was to assess the economic viability of a Tectona grandis plantation subjected to thinning in the State of Mato Grosso and to compare the results with others Tectona grandis plantations in the state. There were simulated 4 forestry management alternatives with variations in the intensity of thinning, at 5, 10 and 15 years of age. It was considered a planning horizon of 20 years. Independent of the management alternative adopted, all were economically unviable, according to the Net Present Value (NPV) and Internal Rate of Return (IRR) methods. This behavior can be explained by the rate growth of the forest, which in this study was very low. It was designed a new stage of growth and carried out new economic analysis. From this new scenario, all forestry alternatives management were considered viable for the production of round wood. The alternative of 35, 35 and 25% reduction in basal area, for ages 5, 10 and 15 years respectively, was the most economically viable. The IRR for these management alternatives was higher than others, reaching 12%. Source


Stape J.L.,North Carolina State University | Binkley D.,Colorado State University | Ryan M.G.,U.S. Department of Agriculture | Ryan M.G.,Colorado State University | And 14 more authors.
Forest Ecology and Management | Year: 2010

We examined the potential growth of clonal Eucalyptus plantations at eight locations across a 1000+ km gradient in Brazil by manipulating the supplies of nutrients and water, and altering the uniformity of tree sizes within plots. With no fertilization or irrigation, mean annual increments of stem wood were about 28% lower (16.2 Mg ha-1 yr-1, about 33 m3 ha-1 yr-1) than yields achieved with current operational rates of fertilization (22.6 Mg ha-1 yr-1, about 46 m3 ha-1 yr-1). Fertilization beyond current operational rates did not increase growth, whereas irrigation raised growth by about 30% (to 30.6 Mg ha-1 yr-1, about 62 m3 ha-1 yr-1). The potential biological productivity (current annual increment) of the plantations was about one-third greater than these values, if based only on the period after achieving full canopies. The biological potential productivity was even greater if based only on the full-canopy period during the wet season, indicating that the maximum biological productivity across the sites (with irrigation, during the wet season) would be about 42 Mg ha-1 yr-1 (83 m3 ha-1 yr-1). Stands with uniform structure (trees in plots planted in a single day) showed 13% greater growth than stands with higher heterogeneity of tree sizes (owing to a staggered planting time of up to 80 days). Higher water supply increased growth and also delayed by about 1 year the point where current annual increment and mean annual increment intersected, indicating opportunities for lengthening rotations for more productive treatments as well as the influence of year-to-year climate variations on optimal rotations periods. The growth response to treatments after canopy closure (mid-rotation) related well with full-rotation responses, offering an early opportunity for estimating whole-rotation yields. These results underscore the importance of resource supply, the efficiency of resource use, and stand uniformity in setting the bounds for productivity, and provide a baseline for evaluating the productivity achieved in operational plantations. The BEPP Project showed that water supply is the key resource determining levels of plantation productivity in Brazil. Future collaboration between scientists working on silviculture and genetics should lead to new insights on the mechanisms connecting water and growth, leading to improved matching of sites, clones, and silviculture. © 2010 Elsevier B.V. Source


Ryan M.G.,U.S. Department of Agriculture | Ryan M.G.,Colorado State University | Stape J.L.,North Carolina State University | Binkley D.,Colorado State University | And 13 more authors.
Forest Ecology and Management | Year: 2010

Wood production varies substantially with resource availability, and the variation in wood production can result from several mechanisms: increased photosynthesis, and changes in partitioning of photosynthesis to wood production, belowground flux, foliage production or respiration. An understanding of the mechanistic basis for patterns in wood production within a stand and across landscapes requires a complete annual carbon budget. We measured annual carbon flows to wood production, foliage production and total belowground carbon flux (the sum of root production, root respiration, and mycorrhizal production and respiration) from ages three to five years in clonal Eucalyptus plantations at four sites in Brazil to test if fertility, water availability and stand structure changed wood production and by what mechanism. We also quantified the patterns in light interception and the efficiency of light use to provide additional mechanistic insights into growth responses and to determine if light-use efficiency was related to changes in flux and partitioning. The routine level of forest fertilization at these four sites was high enough that further increases in nutrient supply did not increase wood growth. Irrigation increased wood net primary productivity (age three to five) from 1.45 to 1.84 kg m-2 year-1 of C (27%), because of increases in light interception (5%), photosynthetic efficiency (from 0.028 to 0.031 mol C/mol photons absorbed, 11%), gross primary productivity (from 3.62 to 4.28 m-2 year-1 of C, 18%), and partitioning to wood (from 0.397 to 0.430 of photosynthesis, 8%). These changes increased light-use efficiency by 20%. Annual flux belowground varied among sites from 0.43 to 1.0 m-2 year-1 of C but did not vary with water availability. Across the four sites for the irrigated and unirrigated treatments, light-use efficiency was positively correlated with gross primary productivity and partitioning to wood production. Increasing heterogeneity of stand structure (resulting from staggered timing of planting within plots) led to a 14% loss in wood biomass relative to uniform stand structure at age six. Light-use efficiency, gross primary productivity, and wood net primary productivity were lower, but not significantly so, in heterogeneous compared to uniform stands. Source

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