MASSA SECA E ACÚMULO DE NUTRIENTES EM MUDAS ENXERTADAS DE PEREIRA EM SISTEMA HIDROPÔNICO

RESUMOO trabalho objetivou determinar a produção de massa da matéria seca das partes da planta e o acúmulo total de macro e micronutrientes pelas mudas enxertadas de cultivares de pereira em condições hidropônicas. Utilizou-se do delineamento experimental inteiramente casualizado, em esquema fatorial 3x 3, com quatro repetições. Os fatores emestudo foram: três cultivares (Triunfo, Tenra e Cascatense) e três tipos de enxertia (borbulhia em placa - BP; borbulhia em ‘T’ invertido – BT, e garfagem de fenda cheia –GF). Avaliaram-se a massa seca da parte área, do sistema radicular e total, e o acúmulo total de nutrientes. O método de enxertia de garfagem de fenda cheia e as cultivares Tenra e Triunfo são indicados para a produção de mudas de pereira em sistema hidropônico. No acúmulo de nutrientes nas mudas de pereira, independentemente da cultivar, estabeleceu-se a seguinte ordem para macronutrientes: N>Mg>K>Ca>P>S; e para os micronutrientes: Fe>Mn>B>Zn>Cu.

Alcatrão ou creosoto de eucalipto na produção de adesivos fenólicos para colagem de madeira

This study has shown that Eucalyptus tar and creosote can be used in phenolic adhesive formulations (resols) for wood products bonding. Some adhesives were prepared substituting 0; 17.7; 35.0 and 67.0% of the phenol by anhydrous tar and 0; 15.0 e 28.5% by creosote. In gluing Brazilian pine veneers, eucalypt tar and creosote based adhesives required longer pressing times for curing than conventional phenol-formaldehyde adhesives. By using 13C NMR, the number of carbons in side chains and hydroxyl, carbonyl, carboxyl and methoxyl groups related to 100 aromatic rings could be estimated in tar and creosote. In creosote, after reaction with excess formaldehyde in alkaline medium, only 0,28 hydroxymethyl groups was detected per phenolic ring. This low amount of hydroxymethylation explains the lack of reactivity in curing observed when creosote was introduced in a standard adhesive formulation.

Relação entre as massas úmida, seca e de cinza em materiais biológicos - uma ferramenta para amostragens em campo e análise de amostras

Little is known about the amount of water and ash in brazilian foodstuffs and plants. The relationships between fresh, dry and ash weight were determined in 40 different biological samples. It could be an important tool when one studies biological material containing low concentration of the chemical elements. This study address to determine these relationships and to provide the amount of biological material that one needs to collect. It aims to supply information that could be used to improve the detection limit, precision and accuracy of the analytical methodology utilized.

Produção de matéria seca e de grãos por plantas de feijoeiro (Phaseolus vulgaris L.) cultivadas em solos tratados com metais pesados

This work aimed at evaluating the contents of extractable Cd, Pb, Zn and Cu with a solution of DTPA (diethyleneaminopentacetic acid) and to relate them with the production of dry material and grain production of bean plants under two conditions of experimentally contaminated soil materials with Cd, Pb, Cu and Zn: (i) samples of distrofic red latosol and (ii) humic yellow-red latosol. A decrease in the yield of dry matter was observed for all treatments, if compared with the zero-dose control sample; the grain yield was affected for the soil samples treated with Cd and Cu but only slightly for those treated with Pb and Zn.

Caracterização das O-acetil-(4-O-metilglicurono)xilanas isoladas da madeira de Eucalyptus urograndis

The O-acetyl-4-O-methyl-(glucurono)xylans were isolated from E. urograndis by extraction with dimethyl sulfoxide, analysed for monosaccharide composition and structurally characterized by NMR spectroscopy. These xylans contained one 4-O-methyl-glucuronic acid substituent and 5.5 acetyl groups for approximately 10 xylose residues. About 10% of 4-O-methyl-glucuronic acid (MeGlcA) units were branched at O-2. The O-acetyl-4-O-methyl-(glucurono)-xylans were composed of the following (1 → 4)-linked β-D-xylopyranosyl structural elements: unsubstituted (51 mol%), 2-O-acetylated (12 mol%), 3-O-acetylated (20 mol%), 2,3-di-O-acetylated (6 mol%) and [MeGlcA α-(1 → 2)] [3-O-acetylated] (11 mol%). The weight-average molar mass and polydispersity of this xylan were 34.9 kDa and 1.16, respectively, as measured by size-exclusion chromatography.

5-desoxiflavonóides e lignana isolados da madeira de Schizolobium parahyba (Vell.) S.F. Blake (guapuruvu)

Four flavonoids, 3,7,4'-trihydroxyflavanone (garbanzol), 7,4'-dihydroxyflavone, 7,4'-dihydroxy-3'-methoxyflavone (geraldone) and 3,4,7,4'-tetrahydroxyflavane (Rel-2R,3S,4S-leucoguibourtinidine, guibourtacacidine) were isolated from the wood of Schizolobium parahyba (Leg., Caesalpinoideae) together with lignan balonofonine, sitosterol, and stigmasterol. The structures were established by IR, NMR and mass spectral data analysis and comparison with literature values.

Relevância de compostos de baixa massa molar produzidos por fungos e envolvidos na biodegradação da madeira

Over the last decade, evidences have been shown that the wood biodegradation by fungi is not only a result of the action of their enzymatic machinery but also of various low molecular weight non-enzymatic compounds, especially in fungi that promote brown and white decay, which in nature are the major wood decaying microorganisms. The present review focuses on the recent theories involving these low molecular weight compounds that act direct or synergistically with lignocellulolytic enzymes to attack the wood main macromolecular constituents, their relevance as potential degradative systems, in the overall wood biodegradation, and also outlines their potential biotechnological applications.

Uma visão sobre a estrutura, composição e biodegradação da madeira

Wood is the main raw material used in the pulp and paper industry. It is a material that presents heterogeneous structure and complex composition, which results in a relatively resistant material to the biodegradation process. In the present review, we attempted to summarize the structural characteristics of wood and describe the chemical nature of its major components to, afterwards, comment about its biodegradation. The role of the enzyme manganese peroxidase in the lignin degradation by a selective white-rot fungus, Ceriporiopsis subvermispora, was highlighted.

Estudo fitoquímico da madeira de Guarea macrophylla (Meliaceae)

In the present work, the crude ethanol extract from wood of G. macrophylla was submitted to liquid/liquid partition between hexane, CH2Cl2, EtOAc and n-BuOH. Each phase was individually chromatographed over silica gel, Sephadex LH-20 or Amberlite XAD-2 to give eight terpene derivatives, such as five sesquiterpenoids (caryophyllene oxide, guai-6-en-10β-ol, spathulenol, aromadendrane-4β,10α-diol and aloaromadendrane-4α,10β-diol) as well as three triterpenoids (cicloart-24-ene-3β,23(R*)-diol, cicloart-24-ene-3β,23(S*)-diol, and cicloart-23E-ene-3β,25-diol). Additionally, were isolated three fatty acids (linolenic, linoleic and stearic), two steroids (sitosterol and stigmasterol) and sacarose. The structures of all these compounds were characterized by spectrometric analysis, mainly mass spectrometry and NMR and comparison of these data described in the literature.

Análise comparativa entre vários métodos de quantificação de hemiceluloses da madeira de eucalipto

Pulp hemicelluloses can be extracted with NaOH and quantified by colorimetric and gravimetric techniques. However the most usual methods to measure eucalyptus pulp hemicelluloses have been through the pentosan method or through xylan analyses by GC or HPLC techniques. In this study a comparison was made between the more traditional methods and indirect method of NaOH 5% extraction followed by colorimetric analyses. It was observed that the content of NaOH 5% extract correlates very well with pulp xylan content and reasonably well with the pentosan content. It is concluded that the 5% NaOH solubility method can be used in replacement of the other two, since it is faster, simpler and less costly to carry out than the others.

Determinação de constituintes químicos em madeira de eucalipto por Pi-CG/EM e calibração multivariada: comparação entre redes neurais artificiais e máquinas de vetor suporte

Multivariate models were developed using Artificial Neural Network (ANN) and Least Square - Support Vector Machines (LS-SVM) for estimating lignin siringyl/guaiacyl ratio and the contents of cellulose, hemicelluloses and lignin in eucalyptus wood by pyrolysis associated to gaseous chromatography and mass spectrometry (Py-GC/MS). The results obtained by two calibration methods were in agreement with those of reference methods. However a comparison indicated that the LS-SVM model presented better predictive capacity for the cellulose and lignin contents, while the ANN model presented was more adequate for estimating the hemicelluloses content and lignin siringyl/guaiacyl ratio.

Determinação de enxofre em amostras vegetais por oxidação via seca em meio alcalino com detecção espectrofométrica

The sulphur take an essential role in plants and it is one of the main nutrients in several metabolic processes. The dry ash oxidation, using alkaline oxidizers agent, is the simplest and most economical form for the oxidation of Organic S to sulfate in plants. The objective of this work is to propose a method for sulfur determination in plants samples using dry ash oxidation and agent oxidizers alkaline. The quantification of S-SO4(2-) in samples was accomplished by turbidimetric method. The results demonstrated that the proposed method for oxidation alkaline was appropriate.

Uso de aditivos na biodegradação de madeira pelo fungo Ceriporiopsis subvermispora: efeito na peroxidação de lipídios dependente de manganês-peroxidase

Ceriporiopsis subvermispora is a selective fungus in the wood delignification and the most promising in biopulping. Through the lipid peroxidation initiated by manganese peroxidase (MnP), free radicals can be generated, which can act in the degradation of lignin nonphenolic structures. This work evaluated the prooxidant activity (based in lipid peroxidation) of enzymatic extracts from wood biodegradation by this fungus in cultures containing exogenous calcium, oxalic acid or soybean oil. It was observed that MnP significant activity is required to promote lipid peroxidation and wood delignification. Positive correlation between prooxidant activity x MnP was observed up to 300 IU kg-1 of wood.

Classificação de resíduos de madeira tratada com preservativos à base de arseniato de cobre cromatado e de boro/flúor

Classification of waste wood treated with chromated copper arsenate (CCA) and boron/fluorine preservatives, according to NBR 10004, was investigated. The leaching test (ABNT NBR 10005) for As and Cr, and solubilization test (ABNT NBR 10006) for F, were applied to out-of-service wooden poles. Concentrations of As and Cr in leachates were determined by ICP-MS and of F by ESI. Values for As were higher than 1 mg L-1 classifying the waste as hazardous material (Class I) whereas values for F (> 1.5 mg L-1) were non-hazardous but indicated non-inert material (Class IIA).

Correlação entre precursores e voláteis em café arábica brasileiro processado pelas vias seca, semiúmida e úmida e discriminação através da análise por componentes principais

The influence of pre-processing of arabica coffee beans on the composition of volatile precursors including sugars, chlorogenic acids, phenolics, proteins, aminoacids, trigonelline and fatty acids was assessed and correlated with volatiles formed during roasting. Reducing sugars and free aminoacids were highest for natural coffees whereas total sugars, chlorogenic acids and trigonelline were highest for washed coffees. The highest correlation was observed for total phenolics and volatile phenolics (R= 0.999). Experimental data were evaluated by Principal Components Analysis and results showed that washed coffees formed a distinct group in relation to semi-washed and natural coffees.