Manejo nutrimental de árboles de pino híbrido y uso de ácido indolbutírico para su clonación por estacas

Las estacas de árboles jóvenes de pino presentan bajas tasas de enraizamiento, lo que dificulta su clonación; sin embargo, la fertilización y podas programadas promueven la producción de estacas juveniles. La aplicación exógena de auxinas favorece la formación de raíces. En este trabajo se analiza el efecto del manejo nutrimental de los árboles donadores, de cuatro años de edad, del híbrido Pinus elliottii var. elliottii × Pinus caribaea var. hondurensis y del ácido indolbutírico (AIB) en el enraizamiento de estacas. En un diseño de bloques completos con arreglo factorial, se evaluó la aplicación de cinco nutrimentos o mezclas de ellos a los árboles. Los tratamientos y dosis por árbol fueron: testigo, nitrógeno (80 g), fósforo (20 g), magnesio (10 g) y nitrógeno/fósforo (80/20 g). Además, se probaron dos dosis de AIB (0 y 3 000 ppm) para el enraizamiento. La supervivencia de estacas, el porcentaje de enraizamiento y la morfología de raíces, se registraron después de 90 días. El manejo nutrimental y el AIB mejoraron tanto la morfología de raíces primarias y secundarias, como el enraizamiento de estacas en más de 30 %, respecto a sus testigos. Lo anterior permitió una mayor supervivencia de estacas durante la formación de raíces. Con el tratamiento de N+P se obtuvo la mejor respuesta, superior a 60 %, en todas las variables evaluadas. La clonación de árboles jóvenes del híbrido, por el enraizamiento de estacas, es posible con el apoyo de un programa de fertilización, aplicado como parte del manejo del árbol donador y el uso de AIB.

EFFECTS OF METEOROLOGICAL VARIABLES ON Pinus caribaea GROWTH IN DIFFERENT AGES AT THE AMAZON REGION.

This study compares the impact of five meteorological variables on the diametric growth of Pinus caribaea var. hondurensis Barrett & Golfari in Vilhena, Rondônia. One thousand nine hundred sixty-eight trees were evaluated and classified at different ages: 600 trees were one year old; 600 trees were two years old; 768 trees were 13 years. The diameter measurement at the soil level (SL) was conducted in young stands between one and two years old. In the stand with 13 years old, the diameter was measured at 1.3 m (DCH). Using a Pressler borer, 50 increment cores were removed at DCH to measure the tree rings in LINTAB™ 6. The diametric growth was evaluated through the Periodic Increment (PI) for young stands and Current Annual Increment (CAI) for adult stands. The following variables were considered: average temperature (°C), precipitation (mm), solar radiation (Kj m-²), real evapotranspiration (mm), and maximum relative humidity (%). The Pearson Correlation Coefficient (r) proposed by Callegari-Jacques and the coefficient of variation (CV%) were used to establish the relationship between growth and meteorological variables. For young stands, the variables with higher positive correlation were real evapotranspiration and maximum relative humidity. However, the variable with a higher positive correlation in adult stands was average temperature, demonstrating a strong correlation until the sixth year of the species.

Nota Técnica. Variación longitudinal de densidad y peso específico básico en Pinus caribaea var. hondurensis de 25 años de edad, proveniente de las plantaciones de Uverito, (Monagas, Venezuela).

Se presenta el estudio de densidad (verde, seca al aire, seca al horno) y peso específico básico de Pinus caribaea var. hondurensis (Sénécl) W. Barret & Golfari (Pinaceae) procedente de plantaciones de 25 años de edad de la región de Uverito, estado Monagas (Venezuela) en tres niveles de altura: sección basal, media y apical para conocer su variación en sentido longitudinal. Se tomaron muestras en seis individuos y se prepararon siguiendo el procedimiento indicado por Hoheisel (1968). La densidad y peso específico mostraron los mayores valores en la sección basal, sin embargo, desde el punto de vista estadístico, no existieron diferencias significativas entre los tres niveles de altura y se puede indicar que las propiedades estudiadas tienden a mantenerse constantes en sentido longitudinal.

Performance Characteristics of a Cooking Stove Improved with Sawdust as an Insulation Material

In developing countries, energy demand from biomass has increased due to exponential population growth. This has translated into voluminous quantities of wood being used. The situation is exacerbated by the popular use of inefficient stoves with low thermal insulation, hence contributing to deforestation. In this study, the performance of a cooking stove improved with sawdust as an insulation material was assessed. An insulated fire stove prototype of 26 cm saucepan diameter was designed, constructed, and cast with sawdust and clay in a ratio of 1 : 1 (as the first layer) and sawdust alone as the second layer. The developed stove was tested using a water boiling test to establish its operating performance. The thermal efficiency of the stove was assessed using indigenous wood fuels used in rural Uganda (Senna spectabilis, Pinus caribaea, and Eucalyptus grandis). Computational fluid dynamics was used to simulate the temperature and velocity fields within the combustion chamber and for generating temperature contours of the stove. Obtained results indicated that S. spectabilis had the highest thermal efficiency of 35.5 ± 2.5%, followed by E. grandis (25.7 ± 1.7%) and lastly P. caribaea (19.0 ± 1.2%) in the cold start phase when compared with traditional stoves. The stove remained cold as hot air was restricted to the combustion chamber with decreasing temperature contours toward the outer wall up to the ambient temperature. The velocity flow remained constant as the chamber was colored green throughout due to the shielding of the stove with sawdust as insulation. The heat flux generated indicated that a thick layer of 6 cm or more could ensure good insulation, and this could be further reduced by introducing more sawdust. The designed stove has the potential to reduce biomass consumption and emissions when compared to traditional cookstoves. The inclusion of a chimney draught in the fire stove prototype could reduce smoke and increase thermal efficiency. Further studies should focus on minimizing the thickness of the clay-sawdust (first) layer and increasing the thickness of the sawdust layer to reduce the weight of the fire stove.

Pinus caribaea (Caribbean pine).

P. caribaea, especially P. caribaea var. hondurensis, is widely planted throughout the American, Asian, and African tropics and subtropics. It is fast growing and has very versatile wood. P. caribaea var. hondurensis is the most productive of the three varieties of P. caribaea. P. caribaea var. hondurensis grows on a wide variety of sites in the tropics and subtropics at altitudes below 800 m (Whitmore and Liegel, 1980), although it also grows well up to altitudes of 1500 m or more. Worldwide interest has been focused on rapid-growing selections and provenances of the variety hondurensis. It has been found that var. hondurensis crossed naturally with P. oocarpa, and P. oocarpa var. ochoterenai produces progeny that have better form and are faster growers than their parents (Perry, 1991). P. elliottii crossed with P. caribaea var. hondurensis has made a major contribution to the success of commercial forestry in Queensland, Australia. These successes have also stimulated interest in hybrids in other countries such as South Africa, Brazil and Fiji.

SUCCESSFUL INCORPORATION OF CRUSHED PINE (PINUS CARIBAEA) LEAVES INTO COCONUT COIR DUST NURSERY MEDIUM FOR VEGETABLE SEEDLING PRODUCTION

Different soilless media are used in vegetable nurseries for high quality seedling production. In the current research, potential of incorporating crushed pine leaves (CPL) into coconut coir dust (CCD) as an economical and sustainable media alternative for vegetable nursery trays, was investigated. CPL was used as mixtures with CCD at the ratios of 4:0, 3:1, 2:2, 1:3 and 0:4 (Treatment 1-5). Suitability of each treatment as soilless medium was investigated by evaluating their physical and chemical properties as well as biodegradability. Growth performances of the seedlings grown in the treatments were evaluated using brinjal, capsicum, ‘elabatu’ (Solanuminsanum), knolkhol and tomato. The highest water holding capacity, pH and bio-degradability (6.21ml/g; 7.38; 12.6%) were observed in CCD and lowest values were in CPL (1.30ml/g; 5.18; 8.6%). The highest air porosity and bulk density were in CPL (36.7%, 0.32g/cm3) and the lowest were in CCD (2%, 0.23g/cm3). Mixing of these two materials brought those parameters to moderate values which were appropriate for vigorous plant growth. Capsicum, knolkhol and tomato showed higher seedling vigour index, growth rate and root lengths in T2 and T3 mixtures. Brinjal showed the highest values of growth rate and root length in T3 and T4, and seedling vigour index in T3. ‘Elabatu’ showed highest values of growth rate and root length in T4 and T5, and seedling vigour index only in T4. The result concludes that, CPL can be used in nursery medium without any harm to the plants but incorporation of CPL with CCD improves the properties of growth media and assures better seedling growth.

Equações hipsométricas para Pinus sp. na estação experimental de ciências florestais de Itatinga, São Paulo

Dentre as essências florestais cultivadas no Brasil destacam-se as espécies do gênero Pinus, apresentando uma grande concentração na região Sul do país, sendo as espécies mais cultivadas o Pinus elliottii e Pinus taeda. O objetivo deste trabalho foi ajustar equações matemáticas para estimar a altura das árvores em povoamentos de Pinus taeda L, Pinus oocarpa e Pinus híbrido (Pinus oocarpa x Pinus caribaea var. hondurensis), na Estação Experimental de Ciências Florestais de Itatinga – São Paulo. Para isso foi realizado um inventário florestal estratificado e sistemático por idade (21, 22 e 24 anos), utilizando-se amostragem sistemática de 3 parcelas por área. Cada parcela consistiu de 90 árvores das quais foram medidos todos diâmetros à 1,30 m do solo (DAP) e medidas as alturas totais das 10 primeiras árvores de cada parcela mais as 5 dominantes de forma a abranger todas as classes do povoamento. Para o ajuste foram testadas 10 equações hipsómétricas, sendo selecionadas de acordo com os valores de coeficiente de determinação ajustado (R2aj), erro padrão residual (Syx%), coeficiente de variação (CV%), F e análise gráfica de resíduos. A melhor equação ajustada para descrever a relação h/d para as espécies Pinus taeda, Pinus oocarpa e híbrido Pinus (Pinus oocarpa x Pinus caribaea var. Hondurensis) em todas as idades foi a de Prodan.

PHYSICAL PROPERTIES OF WOOD Pinus caribaea var. caribaea, Pinus caribaea var. hondurensis AND Pinus oocarpa FOR PENCIL PRODUCTION

The behavior of the physical properties of wood is important for its use in the industrial sector. Manufacturing for pencil production requires raw material with low specific mass and high dimensional stability. The objective of this study was to evaluate the properties of the physical specific basic mass properties, anhydrous and green, as well as the retractability of the 14 years old Pinus caribaea var. caribaea, 25 years old Pinus caribaea var. hondurensis and 35 years old Pinus oocarpa in the medulla sense of the bark, base and top of the trees. All species come from the Brazilian Cerrado region afforestation. As for dimensional stability, the Pinus caribaea var. caribaea and Pinus oocarpa had similar behaviors to the volumetric contraction, when evaluating the coefficient of anisotropy of wood species of Pinus caribaea var. caribaea had higher values of anisotropy coefficient, however, all tropical pine studied, qualify as a raw material for the pencil industry, being an alternative species traditionally used.

Efeito da modificação térmica nas propriedades físicas da madeira de Pinus caribaea var. hondurensis Barrett & Golfari

A madeira do gênero Pinus é amplamente utilizada na indústria florestal, principalmente no setor moveleiro e civil, sendo assim, importante a busca por técnicas que melhorem e aperfeiçoem as suas propriedades tecnológicas. Neste sentido, o presente estudo teve como objetivo avaliar o efeito da modificação térmica nas propriedades físicas da madeira de Pinus caribaea var. hondurensis sob duas diferentes temperaturas. Foram utilizadas três árvores com idade de 14 anos do campo experimental da Universidade Estadual do Sudoeste da Bahia, em Vitória da Conquista, BA, das quais foram confeccionadas em amostras com dimensões de 30 x 30 x 50 mm. O processo de modificação térmica foi realizado em uma estufa laboratorial a 160ºC e 200°C de temperatura final de ciclo que, somados ao controle, representaram três tratamentos em análise. Foram realizados os ensaios de densidade aparente, umidade, perda de massa, taxa de absorção de água e estabilidade dimensional. Concluiu-se que a modificação térmica alterou as propriedades físicas avaliadas, tornando a madeira menos higroscópica e com maior estabilidade dimensional, além de ter influenciado na coloração da madeira em relação a sua aparência natural.

Variação em propriedades da madeira de Pinus caribaea var. hondurensis e Pinus tecunumanii

Este estudo teve como objetivo caracterizar as propriedades da madeira de Pinus caribaea var. hondurensis e Pinus tecunumanii, em indivíduos de 50 anos de idade, na região de Itirapina, SP. Para isso, foram abatidas cinco árvores de cada espécie, e destas retirados um disco de 7 cm de espessura do diâmetro à altura do peito (DAP). De cada disco foram coletadas amostras em cinco posições diferentes, no sentindo medula-casca, para avaliar as seguintes propriedades: densidade básica, comprimento de traqueíde, espessura da parede de traqueíde, resistência ao cisalhamento e a retração volumétrica. Foi verificado que o Pinus caribaea var. hondurensis e o Pinus tecunumanii não diferem significativamente para as propriedades avaliadas. Entretanto, variaram significativamente, no sentido da medula-casca, para todas as propriedades. A densidade básica, comprimento de traqueíde e a retração volumétrica apresentaram uma tendência crescente no sentido da medula à casca. Para Pinus caribaea var. hondurensis ocorreram correlações positiva entre posição radial com: densidade básica, comprimento e espessura da parede de traqueídes. Com o Pinus tecunumanii ocorreram correlações entre posição radial com: densidade básica, espessura da parede de traqueídes e retração volumétrica.