899 resultados para EUCALYPTUS
Resumo:
The adventitious rooting process of in vitro cultured plantlets is a technique that has been employed for the vegetative propagation of a significant number of native and exotic species. Many factors are associated with the rooting stage influencing positive and/or negatively the establishment of micropropagation protocols. The objective of this work was a literature review of the main inherent factors concerning in vitro rooting process including the correlation among others the endogenous and exogenous auxins levels, juvenility, genotype, mineral nutrition, culture medium conditions, addition of growth regulators and other substances as phenolic compounds and active coal besides growth environmental conditions of in vitro cultures. Although the complete elucidation of all processes involved with rooting of in vitro cultured plants has not been achieved so far, a comprehensive study of the main factors that interfere on rooting is fundamental for the establishment of new researches that might contribute for the rooting of economically important plants.
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This paper evaluated the critical level, responsivity and boron use effciency on growth and the biomass production in six Eucalyptus grandis x Eucalyptus urophylla clones (Ca, Cb, Cc, Cd, Ce and Cf). An experiment was carried out in pots containing ground silicon, under greenhouse conditions using four boron rates per solution (0; 0.135; 0.27; 0.54 mg L -1 of B). The treatments were combined in a randomized block experimental design in a 4 × 6 factorial scheme with three replications. Plant height, stem diameter, dry matter production in the shoots of the plant and boron use effciency in the leaves, stem and total dry matter at the 8th month of age were evaluated. Due to boron fertilization, growth and shoot biomass were observed in the Eucalyptus plants after 240 days of being planted in pots. The increases in growth and biomass were 35 to 54% and 21 to 64%, respectively. The boron rates that promoted major growth of the plants were 0.33 to 0.44 mg L -1 of B and in this range the most effcient clone for dry matter production of leaves was Cf and the least effcient one to stem biomass production and the shoot biomass was Cd, no signifcant differences among other clones were observed. The critical level of boron in solution was 0.09 to 0.24 mg L -1 of B in the growth of the plants.
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Casing layer is one of the most important components of Agaricus spp. production and it directly affects mushroom productivity, size and mass. The aim of this study was to evaluate potential raw materials as a casing layer and their effect on Agaricus brasiliensis productivity. Raw materials from Brazil with potential use were selected and characterized, and the most promising ones were tested as casing layers for mushroom yield. Evaluated raw materials included lime schist, vermiculite, eucalyptus sawdust, sand, São Paulo peat, Santa Catarina peat, subsoil and charcoal. Particle size, porosity and water absorption in relation to mushroom yield for casing layers were determined. Lime schist, an alternate casing layer to peat, is presented and the effects of the casing layer on the mushroom yield are discussed. © 2009 Elsevier Ltd. All rights reserved.
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The aim of this study was to evaluate the effectiveness of 3 solvents (eucalyptol, orange oil, and xylol) on 2 types of gutta-percha (conventional and thermoplastic) and Resilon. Specimens (10 mm diameter × 1 mm thick; n=7 per condition) were prepared and maintained at 37°C for 48 h. Each specimen was weighed on a precision scale every 24 h until its mass was stable, at which time the initial mass was determined. Specimens (n=7) were then immersed in the solvent solutions and, after 48 h at 37°C, they were reweighed at 24- h intervals, until stabilization (final mass). The difference between the final and the initial mass determined the solvent capacity of each solvent. Data were subjected to analysis of variance and Tukey's test at 5% significance level. The results demonstrated that xylol was the most effective, especially on conventional gutta-percha and Resilon (p<0.05). Eucalyptol and orange oil were more effective on thermoplastic gutta-percha than the other materials (p<0.05). It was concluded that all evaluated substances presented solvent action, but xylol was the most effective on both gutta-percha or Resilon.
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The aim of this study was to evaluate Eucaliptus grandis genotypes (Clones 105 and 433) in relation to drought tolerance, through growth plant analysis. Black PVC pots with 10 liter volume were used for cultivate plants in polyethilene greenhouse oriented east/west. Completely randonmized design with four treatments was used: two clones and two minimum soil water potentials (- 0.03 and -1,5 MPa) and sixteen replicates. Pots were weighed daily in order to evaluate water content and characteristic soli water curve was determined. Plant development was obtained each 15 days from planting until 60 days through total dry matter (DM), leaf area index (LAI), leaf area ratio (LAR), net assimilative ratio (NAR), specific leaf area (SLA), relative growth ratio (RGR) and absolute growth ratio (AGR). Results showed that clone 105 presented less sensibility to water deficit, which qualify it as genetic material for use under dry soil conditons. On the other hand, both clones had similar behavior with no water restrictions.
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The aim of this study was to investigate the genetic variation, the genotype × soil interaction and the selection among and within Corymbia citriodora progenies in three different kinds of soils (Red Latossol, Quartz Sand and Purple Latossol), which occur in the Luiz Antônio Experimental Station, São Paulo State, Brazil. The progeny test was established 1983, using 56 open-pollinated families of C. citriodora. Twenty fve years after planting the following traits were measured: height, diameter at breast height (Dbh), stem form and survival. Best growth occurred in Purple Latossol. Significant differences among progenies were detected for most traits in all sites, suggesting the possibility of improvement by selection. In the analysis with sites, Significant differences among locals, progenies and genotypes × soil interaction were detected, confiming that the tested material has sufficient genetic variation to be explored by selection in all sites. The analysis of genotype × soil interaction indicates that growth traits present single interaction and the same progenies can be selected in each site. On the order hand, genotype × soil interaction for stem form and survival was complex; and specifc progenies need to be selected for each kind of soil. The population, due to its high genetic variation and strong genetic control of traits, permits to obtain considerable genetic gains by selection among and within progenies.
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Among the several variables that influence timber harvesting is the slope, which influences the productivity of forest machines. In this experiment the harvester was evaluated technically and economically while cutting and processing eucalyptus activity on different slope classes. The technical analysis included a study of time and movements by the method of continuous time; productivity was determined by the volume in cubic meters of wood processing. The economic analysis included the parameters of operational cost, production cost and energy consumption. The analysis of the data showed that productivity decreased according to the increase of the percent slope inclination, resulting in an effective work hour productivity increase from 18.72 to 39.71 m 3sc, with a mean of operating cost of US$ 78.78 per work hour.
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INTRODUCTION: Microsporum canis is the most common cause of canine and feline dermatophytosis and thus has an important zoonotic role. OBJECTIVES: the aim of this study was to determine the antifungal action of medicinal plant extracts and of eucalyptus oil against pathogenic fungus Microsporum canis. METHODS: the extracts were prepared by mixing 300 g of previously washed leaves with 450 mL of distilled water. Then the material was triturated, filtered, sterilized and conserved at 10 + 2 oC. Fifteen milliliters of sterilized medium Sabouraud dextrose (Difco) at a temperature of 55 + 1 oC was added in Petri dishes containing the extracts in one, two, three, four and five mm concentrations. The fungus was inoculated once the medium was solidified. The inoculated dishes were maintained in B.O.D. incubator at 36 ± 0,5 oC until the fungus developed in the controls. RESULTS: the extracts from Punica granatum, Mangifera indica and Eucalyptus spp reduced the growth of fungus, but the extracts from Cymgopogom nardus, Tagetes minuta, Ruta graviolens, Cyperus rotundus, Annona moricata and Calendula spp leaves and flowers boosted the growth of fungus. The other extracts and the eucalyptus oil neither show any fungicidal action nor encourage mycelium growth. CONCLUSIONS: the use of most tested extracts and eucalyptus oil is not suitable for the treatment of Microsporum canis dermatophytosis due to lack of inhibitory effects. The extracts from Cymgopogom nardus, Tagetes minuta, Ruta graviolens, Cyperus rotundus, Annona moricata and from of Calendula spp leaves and flowers help the development of the fungus making clear that phytotherapy should be properly used, otherwise it can worsen the problem. However; extracts from Mangifera indica, Punica granatum and Eucalyptus spp. can be used as fungistatic.
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This work aimed to evaluate the effect of cattle manure levels in the phase of implementation Corymbia citriodora (Hook.) K. D. Hill & L. A. S. Johnson (Eucalyptus citriodora) seedlings in field, produced from seeds collected from four mother trees. The experiment was carried out in green house, in pots filled with 5 dm 3 of Oxisol. Five cattle manure levels were applied 0, 10, 20, 30, and 40 t ha -1 (0, 25, 50, 75, and 100 g pot -1). All treatments received lime levels which were calculated to increase the base saturation degree to 50%. The soil fertility was evaluated after 30 days of soil incubation with manure and lime. The seeds were collected from mother trees called 2, 8, 20 and 29. Sowing was performed directly in rigid plastic containers of 50 cm 3 and seedlings were transplanted when they were around 17 cm height. The experimental design was entirely randomized, in a factorial 5 × 4 (five doses of cattle manure and seeds of four mother trees) scheme and four repetitions. Each parcel was a pot with two plants. At 90 days the height, foliar area, stalk diameter, shoot and root dry matter. The plants responded positively to application of manure, but differently for each evaluated growth characteristic linearly or quadratically. The manure levels had linear effects on growth characteristics and dry matter production of the plants from mother trees 2 and 20 moreover these plants require more cattle manure levels than ones from mother trees 8 and 29. The cattle manure promoted the best development of plants from mother trees 8 and 29, in relationship with dry matter production of shoot components was approximately 27 t ha-1, equivalent to 67.5 g pot.
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By remote sensing, geodatabase digital processing, information and expeditions to Capivara's sub-basin, was possible to identify the changes in the landscape mainly the expansion of eucalyptus, sugar-cane, and orange trees, being the last two, mainly on the Periferic Depression of Basaltic Cuesta. A significant portion of the soil on this geological area is formed from sandstones, providing high permeability to them, making them important places to groundwater recharge areas as sensible to contamination by pesticides. Throughout last decade was observed that the native vegetation fragments stabilization, keeping a reason of 26.5% on the land used between 2000 and 2010. The pasture decrease being substituted by eucalyptus, sugar-cane and orange trees call attention for the changes in the agribusiness model demanded by the current economic and social necessity. Pasture decrease followed by erosions decrease on sub-basin is evidence that these two aspects are strongly related.
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This study aimed to evaluate the acclimatization effects in the Eucalyptus grandis vs. Eucalyptus urophylla seedlings nursery in their initial growth in two soils types, clay and sandy. The seedlings were planted in Plantmax substrate and in rice hulls plus vermiculite, and managed, after 60 days of the mass propagation (DAE), during the rustication. There were five different frequencies of subsurface drip irrigation, restoring the soil field capacity condition: F1, F2, F3 and F4, which were irrigated once, twice, three and four times a day, respectively, and FD, kept in continue irrigation until planting at 90 DAE. In a randomized block design with four replications, plant height (HPA) were evaluated at 6 and 13 months after planting and the diameter at breast height (DAP) at 13 months after planting. Findings show that water management at hardening phase seedlings had no influence on growth in both soils.
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The aim of this study was the selection of Corymbia citriodora provenances for three different kinds of soils occurring in Luiz Antônio Experimental Station, São Paulo, Brazil (Latossolo Vermelho, Areia Quartzosa and Latossolo Roxo). The provenance test was established in 1983, with ten Corymbia citriodora provenances and one Eucalyptus grandis as control, original from a seed production area. The trials were established in a random block design with 11 treatments, three repetition and square plots with 25 trees. In 2008, there were evaluations of height, diameter at breast height (DBH, 1.3 m), stem form and survival. Significant differences among soils and provenances were detected for the growth traits, stem form and survival in all those studied soils. Significant provenance and soil interactions were not detected. All provenances showed higher growth in height and DBH in Purple Latosol. The control had a higher growth rate in relation to highness, DBH and stem form than Corymbia citriodora provenances in all the studied soils, but it presented, generally, a lower survival rate than Corymbia citriodora provenances. Pederneiras (11) Corymbia citriodora provenance presented a higher performance in relation to highness and DBH in all kinds of soils, and Gilgandra (4) provenance, original from Australia, had the worst development. Therefore, Pederneiras (11) provenance is, therefore, the best choose for reforestations in all those studied soils.
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Many studies have recommended the use of small plots for forest experiments, although they do not consider the inter-genotype competition increase. If this competition is not isolated from the mathematics model, it can lead to incorrect selection of genetic materials. The aim of this work was to evaluate the effect of seven competition covariates in two Eucalyptus spp. progeny tests. Data from the two half-sib eucalyptus progenies were analyzed, using the randomized blocks design. The seven analyzed covariates were HegyI's competition index (IC), self-competition (AT), alo competition (AL), self-competition mean (MAT), alo competition mean (MAL), and arithmetic means of four (M4) and eight (M8) nearest neighbors. Individual and combined analyses of covariates were used for the wood volume trait. All the variance components and the changes caused by covariates use were evaluated. The competition affects the results of eucalypt progeny analysis in different ways, according to its type, self or alo competition. Most influential covariates were MAT, MAL and IC. Most promising results of competition effects reduction were observed for the IC/MAT covariates inclusion in eucalypt progeny tests.
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This study intends to evaluate the effects of landscape physical elements (rocks and relief) associated with silviculture activities. The study was carried out on a small farm (Fazenda Santa Edwirges) covered by Eucalyptus forested situated in the Paraiba do Sul Basin, Southeast Brazil. The methodology consisted of detailed geological and geomorphological studies at 1:10,000 scale, and laboratory analysis of soil physical properties. The results showed three geologic-geomorphologic associations (ridge escarpment with granitic rocks, steep and gentle hills cut by shear zones and gentle hill with alluvial sediments) present high vulnerability for the development of the physical processes such as accelerated erosion landslides and flooding. In contrast, mountains associated with gneissic rocks present smaller vulnerability and high resilience for the development of the physical processes. The results have showed the importance of considering the interactions among landscape physical for the eucalyptus forest management contributing to a better selection area for eucalyptus cultivation and minimize adverse environment impact in road design.
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Tick control has been accomplished through the use of synthetic acaricides, which has created resistant individuals, as well as contaminating the environment and nontarget organisms. Substances of plant origin, such as oils and extracts of eucalyptus and neem leaves, have been researched as an alternative to replace the synthetic acaricides. Ricinoleic acid esters from castor oil have recently been shown as a promising alternative in eliminating bacterial contamination during ethanol fermentation, by acting as an effective biocide. The same positive results have been observed when these esters are added to the food given to tick-infested rabbits. This study tested the effect of these substance on the reproductive system of Rhipicephalus sanguineus females, added to rabbit food, more specifically on oogenesis. For this, four groups were established: four control groups (CG1, CG2, CG3, and CG4) and four treatment groups (TG1, TG2, TG3, and TG4) with one rabbit in each (New Zealand White), used as hosts. After full 4 days feeding (semi-engorgement), the females were collected and had their ovaries extracted. In this study, it was observed that R. sanguineus females exposed to esters had their ovaries modified, which was demonstrated through transmission electron microscopy techniques. The addition of ricinoleic esters to the diet of tick-infested rabbits revealed how toxic such substances are for the cytoplasmic organelles of oocytes and pedicel cells. These compounds can change the morphophysiology of germ and somatic cells, consequently influencing their viability and, therefore, confirming that the ricinoleic acid esters from castor oil are a promising substance in the control of R. sanguineus. © 2012 Springer-Verlag Berlin Heidelberg.