ABSTRACT The objective of this work was to evaluate environmental effect on growth, wood basic density and anatomical characteristics of Eucalyptus grandis × Eucalyptus urophylla clones for pulp production. The studied clones were from 6.5-year-old plantations of Fibria Celulose company, located in two places: Nova Almeida (ES) and Posto da Mata (BA). The total and commercial heights, diameter at breast height (DBH), wood and bark volume (dendrometric characteristics), heartwood and sapwood percentages, wood basic density and wood fibers and vessels were evaluated. The heartwood and sapwood percentage and vessel frequency were the only characteristics not influenced by the growth site among the studied parameters. On the other hand, tree height (total and commercial) was considered the most influenced by the environment.

RESUMO O objetivo deste trabalho foi avaliar a influência de diferentes áreas úteis proporcionadas pelos espaçamentos de plantio (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) na produção e na permeabilidade do cerne e do alburno da madeira de clones de Eucalyptus grandis e Eucalyptus grandis × Eucalyptus urophylla, aos 4 anos de idade. Independente do clone, não houve efeito do espaçamento de plantio na relação cerne/alburno e na permeabilidade da madeira. Todos os clones apresentaram um decréscimo na quantidade de cerne com o aumento da altura do fuste, independentemente do espaçamento de plantio, e o E. grandis (B) foi o único que a percentagem de cerne correlacionou-se positiva e significativamente com as variáveis dendrométricas (DAP e altura comercial). O uso do composto dymethil yellow foi indispensável na demarcação das regiões do cerne e do alburno nas amostras a partir de 50% da altura do fuste. A permeabilidade do cerne foi baixa em todos os clones avaliados, sugerindo obstrução dos vasos por tilas ou outras substâncias, enquanto a permeabilidade do alburno atingiu 405,4 cm3/cm.atm.s.

ABSTRACT The objective of this work was to evaluate the influence of different useful areas provided by the planting spacings (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) on the production and permeability of heartwood and sapwood of Eucalyptus grandis and Eucalyptus grandis × Eucalyptus urophylla clones at 4 years old. Regardless of the clone, there was no effect of planting spacing on the heartwood/sapwood relation and wood permeability. All clones showed a heartwood decrease with increased height, regardless of planting spacing, and E. grandis (B) was the only one that had its heartwood percentage positively and significantly correlated with the dendrometric variables (DBH and commercial height). The use of the dymethil yellow compound was indispensable in defining the heartwood and sapwood regions in the samples from 50% of the stem height. The heartwood permeability was low in all evaluated clones, suggesting vessel obstruction by tyloses or other deposits, while sapwood permeability reached 405.4 cm3/cm.atm.s.

ABSTRACT This study aimed to evaluate the environmental effect on the wood chemical composition of Eucalyptus grandis x Eucalyptus urophylla clones for pulp production. Seven clones of 6.5 years old were evaluated. The clones were planted in two growing sites, Nova Almeida - Espírito Santo and Posto da Mata - Bahia, established in 3 x 3 m spacing. Five trees were selected from each clone and discs were removed from five different positions equidistant from the trunk and at diameter at breast height (DBH) height. Two wedge from opposite sides were obtained from the discs. A chemical analysis was performed with a sample composed of all the wedges of each tree in order to determine extractive contents, lignin, holocellulose, carbohydrates and the ratio among syringyl (S) and guaiacyl (G) lignin substructures (S/G) per tree. The S/G ratio was considered to be the most stable characteristic to environmental change, followed by the holloceluloose content, which was considered the second least characteristic influenced by the growth site. Most of the studied clones presented a statistical difference between the growing site for the wood extractive content, in contrast to the total carbohydrates content that was highlighted by presenting values which were little influenced by the genetic material and the growth site.

Abstract: The aim of the research was to evaluate the effect of the attack Leptocybe invasa in dendrometric variables and wood properties of two clones of eucalyptus (Eucalyptus urophylla and Eucalyptus tereticornis), grown in the municipalities of Imperatriz (state of Maranhão) and Darcinopolis (state of Tocantins), Brazil, for Kraft pulping. Data were collected 10 trees for each clone, the 3-year-old attacked by L. invasa. The diagnosed was based on formation of large guts all over the glass, and emergency hole (closing the loop). The results were confirmed by the variation of the characteristics of species assessed relative to their total height, diameter, volume of bark, vessel frequency, fiber size, radial density profile vessel frequency, fiber size, radial density profile, and ash content. Host trees obtained alterations in dendrometric variables, content of pentosans and wood ashes for both genetic materials, not being observed variations in specific gravity, and size of vessels and fibers, as well as the contents of lignin and wood extractives.

Resumen: El objetivo de la investigación fue evaluar el efecto del ataque de Leptocybe invasa en las propiedades dendrométricas de la madera de dos clones de eucalipto (Eucalyptus urophylla y Eucalyptus tereticornis), cultivados en los municipios de Imperatriz (Estado do Maranhão) y Darcinópolis (Estado de Tocantins), Brasil, destinados a la producción de pulpa kraft. Se analizaron 10 árboles de 3 años de edad atacados por Leptocybe invasa, para cada clon. El diagnóstico fue basado en la formación de grandes agallas en la copa, y con orificio de emergencia (cerrando el ciclo). Los resultados fueron constatados por la variación de las características de las especies evaluadas con relación a su altura total, diámetro, volumen de corteza, frecuencia de vasos, longitud de fibras, perfil radial de densidad y contenido de cenizas. Los árboles hospederos presentaron alteraciones en las variables dendrométricas, contenido de pentosanos y cenizas en la madera para ambos materiales genéticos, no siendo observadas variaciones en la densidad básica, dimensión de vasos y fibras, así como en los contenidos de lignina y extractivos de la madera.

ABSTRACT The productive sustainability of eucalyptus planting is threatened when both diseases and disorders of growth occur. These interferences can have abiotic origin as environmental conditions can negatively affect the wood quality. This study has the goal of evaluating influence of different levels of physiological disorders in dendrometric variables and wood quality from seven-year-old Eucalyptus grandis x Eucalyptus urophylla hybrids intended for wood pulping production. The trees from commercial plantations in State of Maranhão, Brazil were separated into three levels of physiological disorders by means of morphologic changes. Then, they were evaluated according to dendrometric variables, anatomical characteristics, chemical properties, density of wood, and kraft pulp process. The physiological disorder levels significantly influenced all evaluated properties. Moreover, the wood from trees with higher severity of symptoms resulted in higher average values of dendrometric variables, basic density, and fibers dimensions. In addition, apparent density exhibited a different standard in the pith region with increase on radial wood profile. Trees with the least severe disorders exhibited changes in dendrometric and anatomical variables, mainly in wood volume and fibers dimensions, respectively.

RESUMO O crescimento da demanda mundial por madeira implica na busca de novas espécies de rápido crescimento com potencial silvicultural e, nesse cenário, as espécies nativas como o paricá. Assim, o objetivo deste trabalho foi determinar as propriedades físicas e mecânicas da madeira da espécie Schizolobium amazonicum (paricá). As árvores foram coletadas em plantios comerciais localizados no norte do Brasil, com idades de 5, 7, 9 e 11 anos. Das árvores de cada idade foram obtidas quatro toras no sentido longitudinal das árvores e, posteriormente, um pranchão diametral de cada tora para fabricação dos corpos de prova, os quais foram utilizados para avaliar algumas propriedades físicas e mecânicas da madeira. A densidade básica do paricá reduziu no sentido base-topo e não houve diferença entre as posições radiais, em média, a densidade básica dessa madeira caracterizou-se como baixa. A região próxima da casca apresentou menor contração longitudinal, e também, maior homogeneidade dessa propriedade ao longo do tronco, enquanto para a contração tangencial a menor variação foi encontrada na região próxima à medula. A contração da madeira de paricá foi caracterizada como baixa. A idade influenciou a maioria das propriedades mecânicas, tendo a tora da base os maiores valores de resistência mecânica.

ABSTRACT Growth in world demand for wood implies a search for new fast growing species with silvicultural potential, and in this scenario for native species such as Paricá . Thus, the objective of this study was determining the physical and mechanical wood properties of the Schizolobium amazonicum species (known as Paricá in Brazil). Trees were collected from commercial plantations located in the north of Brazil with ages of 5, 7, 9 and 11 years. Four logs from trees of each age in the longitudinal direction of the trees were obtained, and later a diametrical plank of each log was taken to manufacture the specimens which were used to evaluate some physical and mechanical properties of the wood. The basic density of Paricá was reduced in the basetop direction and no difference between the radial positions was observed, while the average basic density of this wood was characterized as low. The region close to the bark showed less longitudinal contraction and also greater homogeneity of this property along the trunk, while for tangential contraction the smallest variation was found in the region near the pith. Paricá wood contraction was characterized as low. Age influenced most of the mechanical properties, where logs from the base had the highest values of mechanical strength.

RESUMO O objetivo deste trabalho foi determinar os efeitos da idade das árvores e das posições medula-casca e base-topo nas características anatômicas e o efeito da idade nos componentes químicos da madeira de Schizolobium amazonicum (paricá). O material foi obtido de plantios comerciais nos estados do Maranhão e Pará, com idades de 5, 7, 9 e 11 anos. Das árvores de cada idade foram obtidas as três primeiras toras (de 2,7 m de comprimento cada). Para a caracterização química da madeira analisou-se apenas o efeito da idade. As dimensões das fibras aumentaram no sentido medula-casca, enquanto a espessura da parede reduziu e o comprimento das fibras aumentou juntamente com a idade. A largura das fibras e o diâmetro do lume aumentaram no sentido base-topo. A madeira de paricá apresentou baixo teor de extrativos e de hemiceluloses, e alto teor de celulose. As características anatômicas foram mais afetadas pelos fatores em estudo do que a composição química, evidenciando que os elementos químicos da madeira são mais estáveis com a idade em relação aos caracteres anatômicos.

ABSTRACT The objective of this study was to determine the effects of tree age and of pith-bark and base-top positions on anatomical characteristics, and the effect of age on the chemical components of Schizolobium amazonicum (Paricá wood). The material was obtained from commercial plantations in the states of Maranhão and Pará with ages of 5, 7, 9 and 11 years. The first three logs (2.7 m length each) were obtained from the trees of each age. Only the effect of age was analyzed for the chemical characterization of the wood. The dimensions of the fibers increased along the pith-bark direction, while wall thickness decreased and the length of the fibers increased with aging. The width of the fibers and the lume diameter increased in the base-top direction. Paricá wood presented low extractive and hemicellulose content, and high cellulose content. The anatomical characteristics were more affected by the factors under study than the chemical composition, evidencing that the chemical elements of the wood are more stable with aging in relation to the anatomical characteristics.

RESUMO O presente trabalho teve como objetivo caracterizar a formação de anéis de crescimento no lenho de Khaya ivorensis, bem como, analisar a variação da morfologia dos elementos de vaso, visando ao entendimento do crescimento dessa espécie em plantios experimentais. Para tanto, discos da base de cinco árvores foram coletados e, após o polimento da seção transversal, realizou-se a demarcação dos limites dos anéis de crescimento. Um estudo anatômico da madeira foi realizado com objetivo de caracterizar os anéis e por meio de imagens digitalizadas dos discos foi mensurada a largura dos mesmos. Foi obtida uma série histórica de dados referente ao diâmetro das árvores para estabelecer uma correlação com a largura dos anéis mensurada ao longo dos anos. Os limites dos anéis de crescimento da madeira de mogno africano são demarcados por uma fina camada de parênquima marginal, tendo sido constatada a presença de falsos anéis. Foi observada entre as árvores correlação de crescimento anual significativa de 0,62, sendo o incremento radial do lenho irregular nos primeiros anos (anéis largos e estreitos), com destaque para o 3º e o 11º ano de crescimento, em que foram observados os maiores incrementos, devido a uma tendência biológica de adaptação ao ambiente e pela ocorrência de um desbaste realizado na área de plantio, respectivamente.

ABSTRACT The objective of this study was to characterize the formation of growth rings in Khaya ivorensis wood, as well as to analyze the variation in the morphology of the vessel elements, aiming to understand the growth of this species in experimental plantations. Disks from the bases of five trees were collected, and after polishing the cross-section, demarcation of the growth rings limits was carried out. The anatomical study of the wood was conducted with the purpose of characterizing the rings, and their width was measured by means of scanned images of the disks. A historical series of data was obtained concerning the diameter of the trees to establish a correlation with the width of the rings measured over the years. The growth rings limits of African mahogany wood are demarcated by a thin layer of marginal parenchyma, and the presence of false rings has been observed. Significant annual growth correlation of 0.62 was observed among the trees, being the radial increment of irregular wood in the first years (wide and narrow rings), and highlighting the 3rd and 11th year of growth in which the largest increases were observed due to a biological adaptation tendency to the environment and the occurrence of thinning carried out in the planting area, respectively.

RESUMO Este estudo objetivou-se avaliar a qualidade da madeira normal, tracionada e oposta no sentido longitudinal de árvores de eucalipto com o fuste reto e inclinado, atingidas por ação de ventos, e explicar os parâmetros da polpação em decorrência da qualidade do lenho. As árvores foram agrupadas em quatro faixas de inclinação variando de 0º a 50º, e avaliado a densidade básica, composição química da madeira, e o desempenho na polpação Kraft. A madeira normal e a tracionada tiveram densidades básicas semelhantes, já a densidade da madeira oposta foi inferior, sendo responsável pela diminuição da densidade básica da madeira de reação. A constituição química da madeira foi influenciada pela presença da madeira de reação no tronco, tendo a madeira tracionada e oposta menores teores de extrativos e ligninas, e maior teor de holocelulose, em relação à madeira normal, sendo favoráveis na qualidade da madeira para a polpação. O aumento do teor de holocelulose e a redução dos teores extrativos e ligninas contribuíram positivamente para obter uma polpa mais deslignificada, e reduzindo o numero kappa. Todavia, quando realizados cozimento na madeira de reação com as mesmas condições da madeira normal, a polpa de reação tende a ter menor rendimento depurado. Em decorrência das diferenças de densidade básica e dos constituintes químicos entre madeira oposta e normal, recomenda-se a não designar a madeira oposta como madeira normal.

ABSTRACT This study aims to evaluate the quality of normal, tension and opposite wood of eucalyptus trees lengthwise, in straight and inclined stems, affected by wind action. It also aims to explain the pulping parameters resultant from the quality of the wood. The trees were grouped into four tilt ranges, ranging from 0 to 50º, and the basic density, chemical composition of the wood, and performance in kraft pulping were assessed. Normal and tension wood had similar basic densities; while for opposite wood, the density was lower, being responsible for a decrease in reaction wood density. The chemical composition of the wood was influenced by the presence of reaction wood in the stem. Tension and opposite wood showed lower levels of extractives and lignin and higher holocellulose content when compared to normal wood, with favorable wood quality for pulping. The increase in holocellulose content and the reduction of lignin and extractives content contributed positively to a more delignified pulp and reduction of the Kappa number. However, after cooking the reaction wood under the same conditions as those of normal wood, reaction wood pulping tends to have a lower screen yields. Due to differences in basic density and chemical constituents between opposite and normal wood, it is recommended not to designate the opposite wood as normal wood.

RESUMO Avaliaram-se os efeitos do teor de umidade e classe diamétrica na qualidade do tratamento de moirões de Corymbia torelliana e Eucalyptus grandis x Eucalyptus urophylla. Utilizaram-se 108 moirões, sendo 36 tratados e 18 não tratados, com 2,20 m de comprimento e umidade de 15 a 20%; 20 a 30%; 30 a 40%, e diâmetros de 8 a 10 cm; 10 a 12 cm; 12 a 14 cm. No tratamento, foram utilizados 2% de ingredientes ativos de CCA-C, vácuo inicial e final de 550 mmHg (30 min), pressão de 11 kgf cm-2 (1 h). Os moirões tiveram a umidade avaliada pelo medidor elétrico, que foi adequado para estimar a umidade destes. Obtiveram-se penetrações satisfatórias e a maior retenção foi obtida nos moirões com umidade de 15 a 20% (8,23 kg m-3), contudo, umidade de 30 a 40% também foi adequada ao tratamento da madeira, obtendo valores superiores a 6,5 kg m-3.

ABSTRACT Were evaluated the effects of moisture content and diametric class in industrial treatment quality of Corymbia torelliana and Eucalyptus grandis x Eucalyptus urophylla fence posts. 108 fence posts were used, 36 treated and 18 non-treated, with 2.20m long and moisture content of 15 to 20%; 20 to 30%; and 30 to 40% and diameters of 8 to 10cm; 10 to 12cm; 12 to 14cm. For treatment, were used 2% active ingredients of CCA-C, initial and final vacuum 550 mmHg (30min), pressure of 11 kgf cm-2 (1h). The fence posts were evaluated by electric meter that was adequate to estimate the moisture. Satisfactory penetrations were obtained and the biggest retention was reached in fence posts with moisture of 15 to 20% (8.23 kg m-3), however, the moisture content of 30 to 40% was also suitable for the treatment of wood, getting values higher than 6.5 kg m-3.

ABSTRACT The objective of this study was to identify eucalyptus clones for the production of sawed timber based on dendrometric variables and longitudinal residual deformation (LRD), analyzing the correlation between these characteristics. 20 Eucalyptus grandis x Eucalyptus urophylla clones with 13 years of age were analyzed. The crown size, diameter at breast height (DBH) and bark thickness were measured. There was a significant difference between the clones for DBH, LRD and bark thickness. There was no significant correlation between DBH and DRL. The correlation was significant between DBH and crown size, its being possible to affirm that crown size affects the diametrical growth of trees. DBH and bark thickness were also significantly correlated, in so far as trees with a wider diameter possess thicker bark. It was possible to select clones with better potential for sawed timber production, that is to say, elevated DBH with a reduced LRD.

RESUMO Árvores inclinadas produzem madeira de reação, cujas propriedades são distintas da madeira normal e, podem afetar na produção de carvão vegetal. Este trabalho foi realizado com objetivo de avaliar a qualidade do carvão vegetal procedente da madeira de reação em árvores de plantio comercial inclinadas por ação de ventos. Utilizou-se madeira de um híbrido de Eucalyptus grandis x Eucalyptus urophylla aos seis anos de idade proveniente de plantios localizados em Minas Gerais. Determinaram-se as propriedades físicas e químicas da madeira, e também o rendimento gravimétrico e as propriedades do carvão vegetal. De acordo com os resultados, houve diferenças significativas entre as propriedades da madeira de reação e normal, tendo a madeira de reação menores teores de lignina e extrativos, maior teor de holocelulose e menor densidade básica. No entanto, essas diferenças na madeira de reação não afetaram significativamente as propriedades do carvão vegetal.

ABSTRACT Inclined trees produce reaction wood, whose properties are distinct from normal wood. This situation can affect the production of charcoal. This study was conducted to evaluate the quality of charcoal derived from reaction wood in trees of a commercial plantation inclined due to the action of wind. We used six year old wood from a Eucalyptus grandis xEucalyptus urophylla hybrid from plantations located in Minas Gerais. The physical and chemical properties of the wood were determined as well as the gravimetric yield and charcoal properties. According to the results, there were significant differences between the properties of the reaction and normal wood, with the reaction wood having lower levels of lignin and extractives, greater holocellulose content and low specific gravity. However, these characteristics of reaction wood did not significantly affect the properties of its charcoal.

RESUMO O objetivo do trabalho foi avaliar a influência da idade, irrigação e espaçamento no volume e densidade básica da madeira de eucalipto. Os materiais utilizados foram dois clones Eucalyptus grandis × Eucalyptus urophylla com idades de 6 e 12 meses provenientes de plantios em duas regiões, uma irrigada e outra região não irrigada, com espaçamentos de 3×0,5; 1,5×2, 3×1; 3×2 e 3×3 m. O volume foi determinado conforme o método de Smalian, sendo determinada também a densidade básica ponderada. Os maiores valores de volume de madeira por hectare foram obtidos nos espaçamentos mais densos e na região irrigada. Nos espaçamentos mais amplos, houve maiores valores de densidade básica da madeira para o clone A, no entanto, no clone B não houve variação em função do espaçamento. Ao comparar os valores médios de densidade para os clones entre região irrigada e não irrigada, os resultados foram iguais na grande maioria dos espaçamentos estudados.

ABSTRACT This study aimed to evaluate the influence of age, irrigation and spacing, on the volume and basic density of Eucalyptus wood. We used two clones of Eucalyptus grandis × Eucalyptus urophylla with age of six and twelve months, sowed in two regions, one irrigated and other unirrigated, with spacing of 3×0.5, 1.5×2, 3×1, 3×2 and 3×3 m. The volume was estimated according to the method of Smalian as well as the weighted density. The larger volume of wood per hectare values were obtained in the close spacing and irrigated region. Wider spacing showed higher specific gravity values timber for clone A; however, clone B didn’t change with spacing. The comparison of average density values for the clones in irrigated and non-irrigated areas, showed similar results in most studied spacings.

RESUMO Durante o desenvolvimento das árvores, esforços mecânicos são gerados com o intuito de mantê-la em equilíbrio e ereta em resposta a diversos fatores ambientais. Estes esforços são conhecidos como tensões de crescimento e variam na sua distribuição e intensidade nas diferentes espécies do gênero Eucalyptus. Portanto, objetivou-se avaliar a deformação residual longitudinal (DRL) e sua relação com as características de crescimento da árvore, propriedade física e mecânica da madeira de clones do híbrido Eucalyptus urophylla × Eucalyptus grandis com 30 e 35 meses de idade, em plantios florestais na região do Vale do Rio Doce, Minas Gerais, em áreas sujeita a forte ação dos ventos, que tem como consequência o tombamento e até mesmo a quebra dessas árvores. A DRL média foi de 0,086mm, e quando associada as outras características da madeira, as correlações não foram significativas. As características de crescimento das árvores, a densidade básica, o módulo de elasticidade (MOE) e módulo de ruptura (MOR) e trabalho absorvido não foram suficientes para explicar o comportamento da DRL.

ABSTRACT During development and growth of trees, mechanical stresses are generated in order to keep it balanced and upright in response to various environmental factors. These efforts are known as growth stresses and can vary in distribution and intensity across different species of the genus Eucalyptus. Thus, the objective was to evaluate the longitudinal residual strains (LRS) and its correlations with tree growth features, physical and mechanical properties of the Eucalyptus urophylla × Eucalyptus grandis hybrid clones. Trees were 30 and 35 months old, located in forest plantations of Vale do Rio Doce, Minas Gerais, in areas subject to wind action, with damping effect and even the breaking of these trees. The LRS measured with extensometer was on average 0.086mm and when associated with other characteristics of the wood, the correlations were not significant. The growth characteristics of trees, basic density, modulus of elasticity (MOE) and modulus of rupture (MOR), and absorbed work were not enough to explain the LRS behavior.

RESUMO A utilização da biomassa como fonte de energia alternativa tem obtido destaque por suas características energéticas, contribuição ambiental e por ser fonte de energia renovável em curto período de produção. O trabalho objetivou avaliar a produção da biomassa e sequestro de carbono de eucalipto em diferentes condições de crescimento. Foram determinadas a densidade básica da madeira, volume individual com e sem casca, biomassa seca, carbono acumulado, dióxido de carbono assimilado e estimativa energética dos componentes da parte aérea de dois clones do híbrido de E. grandis x E. urophylla aos 6 e 12 meses de idade, em diferentes espaçamentos e provenientes de duas áreas, uma irrigada e outra não irrigada. Os maiores valores de biomassa seca e massa de carbono foram provenientes dos clones nos espaçamentos mais adensados e região irrigada. O efeito da irrigação foi significativo nas variáveis estudadas apenas nos clones com 12 meses. A quantidade de CO2 assimilada no fuste, folha e galho foram maiores nos espaçamentos mais amplos e região irrigada dos clones com 12 meses. A estimativa energética do fuste aumentou com a ampliação do espaçamento. Entre os componentes arbóreos, a casca sofreu menor influência dos espaçamentos e irrigação.

ABSTRACT The use of biomass as an alternative energy source has been gaining attention because of its energy characteristics and environmental contribution and because it is renewable in short production periods. The aim of the present study was to evaluate the biomass production and carbon sequestration of eucalyptus grown under different conditions. The basic density of the wood, stem volume with and without bark and dry biomass, accumulated carbon, assimilated carbon dioxide and estimated energy for each shoot component were determined for two hybrid clones of E. grandis x E. urophylla at 6 and 12 months of age, grown at different spacing in two different areas, one with and one without irrigation. The highest dry biomass and carbon accumulation values were observed for plants grown at smaller spacing and with irrigation. A significant effect of irrigation on the variables quantified was only observed for 12-month-old plants. The amount of assimilated CO2 in the stem, leaves and branches was higher for 12-month-old plants grown at larger spacing and with irrigation. The estimated energy of the stem increased with increased spacing. Bark was the shoot component least influenced by spacing and irrigation.