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Colombo, Brazil

The pressing need to increase the number of seedlings planted annually and variability of raw materials for traditional composition of substrates have led to the need to develop studies aimed at evaluating these materials, technically and economically feasible. Based on this, the present study aimed to evaluate the technical feasibility of using fine vermiculite (VF) and component-based renewable coconut fiber (FC), rice hulls (CAC) in different grain sizes and two commercial substrates composed by pine bark semidecomposta (SC) in the composition of substrates for the production of seedlings of Eucalyptus dunnii, and assess the correlation between the physical and chemical properties of the substrates with the quality of the seedlings. 14 treatments were formulated, and the sowing in tubes of 55 cm3. Based on these results, the substrate that provided greater seedling growth of Eucalyptus dunniiCAC was combined with VF, followed by the SC, while those based CAC in different particle sizes, combined or not with CF, gave low growth. Regarding the properties of the substrates, it was identifiedthat the bulk density, total porosity, macroporosity, pH and cation exchange capacity correlated with seedling growth. Source

Neto J.T.F.,Embrapa Amazonia Oriental | de Resende M.D.V.,Embrapa Florestas | de Oliveira M.D.S.P.,Embrapa Amazonia Oriental
Revista Brasileira de Fruticultura

To obtain superior materials it is necessary that the selected genotype fulfills many favorable attributes that satisfy the demands of the consumers, the producers and the processors. Thus, data on the agronomic characteristics for fruit production and weight, involving 50 progenies of Euterpe oleracea were evaluated in a two type lattice designs with two replications and five plants per plot for a period of three seasons. The objective was to estimate genetic and phenotypic parameters and predicting breeding values of individuals and progeny of irrigated Euterpe oleracea in the State of Para aiming the simultaneous selection and breeding using the REML/BLUP methodology. For the selection and estimation of the predicted gains, it was used the indexes based on average ranks and independent levels of elimination, considering a selection intensity of 20 %. Genetic gain of 20.76 % over the average of the experiment was obtained with the selection of the 20 best individuals for fruit production. Over five seasons in the measurement or evaluation of progenies of açai fruit production a little would be added in terms of selection efficiency, being their use unjustified. The index based on average ranks proved the most efficient both in selecting superior progenies for yield and lower fruit weight, being recommended its use in breeding program for açai. Source

Parron L.M.,Embrapa Florestas | Bustamante M.M.C.,University of Brasilia | Markewitz D.,University of Georgia

The Gallery forests of the Cerrado biome play a critical role in controlling stream chemistry but little information about biogeochemical processes in these ecosystems is available. This work describes the fluxes of N and P in solutions along a topographic gradient in a gallery forest. Three distinct floristic communities were identified along the gradient: a wet community nearest the stream, an upland dry community adjacent to the woodland savanna and an intermediate community between the two. Transects were marked in the three communities for sampling. Fluxes of N from bulk precipitation to these forests resulted in deposition of 12.6 kg ha-1 y-1 of total N of which 8.8 kg ha-1 was as inorganic N. The throughfall flux of total N was generally >8.4 kg ha-1 year-1. Throughfall NO3-N fluxes were higher (7-32%) while NH4-N and organic N fluxes were lower (54-69% and 5-46%) than those in bulk precipitation. The throughfall flux was slightly lower for the wet forest community compared to other communities. Litter leachate fluxes differed among floristic communities with higher NH4-N in the wet community. The total N flux was greater in the wet forest than in the dry forest (13.5 vs. 9.4 kg ha-1 year-1, respectively). The stream water had total N flux of 0.3 kg ha-1 year-1. The flux of total P through bulk precipitation was 0.7 kg ha-1 year-1 while the mean fluxes of total P in throughfall (0.6 kg ha-1 year-1) and litter leachate (0.5 kg ha-1 year-1) declined but did not differ between communities. The low concentrations presented in soil solution and low fluxes in stream water (0.3 and 0.1 kg ha-1 year-1 for N and P, respectively) relative to other flowpaths emphasize the conservative nutrient cycling of these forests and the importance of internal recycling processes for the maintenance and conservation of riparian and stream ecosystems in the Cerrado. © 2010 Springer Science+Business Media B.V. Source

Burckhardt D.,Naturhistorisches Museum | Ouvrard D.,Natural History Museum in London | Queiroz D.,Embrapa Florestas | Percy D.,Natural History Museum in London
Florida Entomologist

Evolutionary and biological patterns can be obscured by inadequate or ill-defined terminology. An example is the generally very specific relationship between the sap-feeding hemipteran group, psyllids, and their breeding plants, commonly called host-plants. The literature is clogged with references to so called 'hosts', which are often merely plants on which psyllids were found accidentally, and no immature development was detected. Recently the term host has also been applied by some authors to any plant on which immature or adults feed. Here we propose a terminology to clarify associated plant definitions, and we suggest restricting the use of the term host-plant to plants on which a psyllid species completes its immature to adult life cycle. For the other plant associations we suggest the terms overwintering or shelter plant (plants on which adult psyllids overwinter and on which they may feed), food plant (plants on which adult psyllids feed, but do not breed and do not spend an extended period of time) and casual plant (plants on which adult psyllids land but do not feed). Source

Wendling I.,Embrapa Florestas | Brooks P.R.,University of The Sunshine Coast | Trueman S.J.,University of The Sunshine Coast
New Forests

Low amenability of the eucalypt, Corymbia torelliana × C. citriodora, to vegetative propagation has limited its establishment in plantations. This study determined whether rooting capacity and cutting vigour varied along the central shoot of Corymbia seedlings, and whether these differences are related to stem development and hormone concentrations. Dual-node cuttings were harvested from five positions (nodes 1/2, 3/4, 5/6, 7/8 and 9/10) along the seedling shoot (S1), and cuttings were treated with one of four levels of indole-3-butyric acid (IBA). Root formation, root and shoot growth, stem anatomy, and the concentrations of indole-3-acetic (IAA) and abscisic acid (ABA) were assessed at each shoot position. The central node of the rooted cuttings was harvested for fresh cuttings to observe whether maturation emerged in ramets (S2) from the different ortet positions. Rooting and vigour were highest from the most-apical seedling nodes (7/8 and 9/10 in S1), which had less lignification and sclerenchyma development than more-basal nodes (1/2, 3/4 and 5/6). IAA and ABA concentrations differed little between the seedling nodes. In contrast, cuttings from the ramets (in S2) had similar rooting, vigour, lignification and sclerification to each other, but there were large differences in IAA and ABA concentrations depending on their previous point-of-origin in the seedling. High doses of IBA reduced rooting. Rooting and vigour were related to lignification and sclerenchyma development rather than IAA or ABA concentrations. Mass vegetative propagation of C. torelliana × C. citriodora is achievable because mean rooting percentages in S1 and S2 were 61 and 68 %, respectively, using cuttings from small seedling ortets and their ramets. © 2014, Springer Science+Business Media Dordrecht. Source

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