ANATOMICAL, ULTRASTRUCTURAL, PHYSICAL AND MECHANICAL WOOD PROPERTIES OF TWO-YEAR-OLD Eucalyptus grandis × Eucalyptus urophylla CLONES

Zanuncio, Antônio José Vinha; Carvalho, Amélia Guimarães; Carneiro, Angélica de Cássia Oliveira; Filho, Mário Tomazello; Valenzuela, Paulina; Gacitúa, William; Colodette, Jorge Luiz

doi:10.1590/1806-90882018000200001

Cited by 6 publications

(3 citation statements)

References 27 publications

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“…The average value presented for the wall fraction was 46.14% (Table 2). Woods with fibers with a higher wall fraction index result in greater dimensional instability, however, this high index provides greater mechanical resistance of the wood (Zanuncio et al, 2018). Fibers with a high wall fraction are indicated for the manufacture of tissue paper, as they absorb more liquids (Bonfatti Júnior et al, 2023).…”

Section: Resultsmentioning

confidence: 99%

GROUPING OF CLONES OF 4-YEAR-OLD Eucalyptus spp. FOR PULP AND PAPER

Vicentin,

Ranzini,

Bôas

et al. 2024

Rev. Inst. Florest.

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As in other countries, In Brazil, new genetic materials of Eucalyptus spp. and their hybrids are multiplied through cloning. These materials, currently in experimental trials, must undergo several stages to select the best ones for pulp and paper production. Therefore, new studies on wood quality are essential. Therefore, this study aimed to group 11 clones of Eucalyptus spp. wood, from a clonal plantation in the municipality of Palmital, São Paulo State, for the production of paper and cellulose. For this purpose, four trees of each clone of 4-year-old Eucalyptus spp. were collected. From each tree, a log of 1 m in length was taken from the base of the tree, for the study of the characterization of the basic density and cellular dimensions of the wood. The results showed that there were significant differences between clones for basic density, fiber length, vessel element length and fiber wall thickness. The Runkel ratio, wall fraction and stiffness coefficient did not show significant differences between the different genotypes. From the results obtained, we can conclude that clones can be differentiated only by basic density, fiber length, vessel element length and fiber wall thickness. The Runkel index, flexibility coefficient and wall fraction of Eucalyptus spp. were more efficient to group the clones into two groups.

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Section: Resultsmentioning

confidence: 99%

GROUPING OF CLONES OF 4-YEAR-OLD Eucalyptus spp. FOR PULP AND PAPER

Vicentin,

Ranzini,

Bôas

et al. 2024

Rev. Inst. Florest.

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“…Eucalyptus grandis (W. Hill) Maiden is one of the most commonly used for this purpose [ 6 ]. This species has an excellent genetic basis [ 4 , 7 , 8 ], but most of its genotypes are susceptible to Austropuccinia psidii (G. Winter) Beenken [ 4 , 5 , 9 ]. This fungus, with a wide geographical distribution, is present in four of the five continents threatening Myrtaceae biodiversity, mainly in the Eucalyptus forestry industry [ 10 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

Morphoanatomical Changes in Eucalyptus grandis Leaves Associated with Resistance to Austropuccinia psidii in Plants of Two Ages

Furtado

Silva

et al. 2023

Plants

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The fungus Austropuccinia psidii infects young tissues of Eucalyptus plants until they are two years old in the nursery and field, causing Myrtaceae rust. The characteristics making older eucalypt leaves resistant to A. psidii and the reason for the low levels of this pathogen in older plants need evaluations. The aim of this study was to evaluate the morphological differences between Eucalyptus grandis leaves of different growth stages and two plant ages to propose a visual phenological scale to classify E. grandis leaves according to their maturation stages and to evaluate the time of leaf maturation for young and adult plants. A scale, based on a morphological differentiation for E. grandis leaves, was made. The color, shape and size distinguished the leaves of the first five leaf pairs. Anatomical analysis showed a higher percentage of reinforced tissue, such as sclerenchyma-like tissue and collenchyma, greater leaf blade thickness, absence of lower palisade parenchyma in the mature leaves and a higher number of cavities with essential oils than in younger ones. Changes in anatomical characteristics that could reduce the susceptibility of older E. grandis leaves to A. psidii coincide with the time of developing leaf resistance. Reduced infection of this pathogen in older plants appears to be associated with a more rapid maturation of their leaf tissues.

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“…Essas características estão relacionadas ao arranjo anatômico e constituintes químicos da madeira (celulose, hemiceluloses e lignina) (Menezes, Santini, Souza, Gatto e Haselein, 2014;Zanuncio et al, 2018). As hemiceluloses favorecem trocas de vapor de água com o ar constantemente.…”

Section: Introductionunclassified

Alterações físico-mecânicas na madeira de cambará (Qualea paraensis) termorretificada

Medeiros¹,

Batista²,

Melo³

et al. 2021

MYB

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Objetivou-se analisar o efeito do tempo e da temperatura de tratamentos térmicos nas propriedades físico-mecânicas da madeira de cambará (Qualea paraensis Ducke). Foram confeccionados corpos de prova de 5 lotes da madeira de cambará submetidos ao tratamento térmico em estufa sob temperaturas de 180 °C e 200 °C e períodos de 2 h e 4 h. Determinou-se densidade aparente (ρ12%), perda de massa (PM), umidade de equilíbrio (UE), contrações nos eixos longitudinal (βl), radial (βr) e tangencial (βt), contração volumétrica (βv) e fator anisotrópico (fa). Mecanicamente, a madeira foi avaliada quanto à resistência e rigidez nos ensaios de flexão estática (fM e EM) e compressão paralela às fibras (fc0 e Ec0). Após os tratamentos térmicos, os valores de ρ12% aumentaram, em média, 7,72% e a UE foi reduzida em 24,3%. Os maiores valores de PM (3,67%) foram observados para o tempo de exposição de 2 h em temperatura de 200 °C. Com este tratamento, obteve-se também os menores valores de βt (5,73%) e βv (9,69%). Os tratamentos térmicos aumentaram a densidade aparente, reduziram a umidade de equilíbrio e aumentaram a estabilidade dimensional da madeira. Na maioria dos tratamentos térmicos, observou-se redução da resistência e aumento da rigidez à flexão estática. Ocorreu aumento da resistência e da rigidez à compressão paralela à grã em todas as combinações de tempo e temperatura. De modo geral, a maior estabilidade dimensional com menores perdas da resistência à flexão estática e compressão paralela foram obtidas com o tratamento de 200 °C e tempo de 2 h.

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ANATOMICAL, ULTRASTRUCTURAL, PHYSICAL AND MECHANICAL WOOD PROPERTIES OF TWO-YEAR-OLD Eucalyptus grandis × Eucalyptus urophylla CLONES

Cited by 6 publications

References 27 publications

GROUPING OF CLONES OF 4-YEAR-OLD Eucalyptus spp. FOR PULP AND PAPER

GROUPING OF CLONES OF 4-YEAR-OLD Eucalyptus spp. FOR PULP AND PAPER

Morphoanatomical Changes in Eucalyptus grandis Leaves Associated with Resistance to Austropuccinia psidii in Plants of Two Ages

Alterações físico-mecânicas na madeira de cambará (Qualea paraensis) termorretificada

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