Abstract:R ESU M OObjetivou-se, com o presente trabalho, descrever e testar um método simplificado de baixo custo (IAF-LUX) para estimativa do índice de área foliar (IAF) em comparação com um equipamento comercial (LAI-2000, Li-Cor ® ). Ambos foram avaliados em um seringal e em árvores de lima ácida "Tahiti"; posteriormente, os dois métodos foram comparados com medidas destrutivas de área foliar realizadas em uma árvore adulta de lima ácida 'Tahiti'; notou-se, então, que os desvios dos resultados pelo IAF-LUX em relaç… Show more
“…Las imágenes fueron procesadas con la ayuda de software Image J. Posteriormente el material fue acondicionado en bolsas de papel tipo Kraft y llevado a una estufa con circulación de aire a 65°C hasta alcanzar peso constante y, posteriormente pesadas en balanza analítica, para la determinación de la MSF, MSTR y MSPA. El AF fue obtenida de acuerdo a adaptaciones de la metodología de Coelho-Filho et al (2012), utilizando la siguiente fórmula:…”
Light is an important environmental factor in the establishment of vegetation. The knowledge of the behavior of the species in response to light demand for survival and growth in the field becomes essential. Thus, the present study aimed at evaluating the survival and initial growth of Myrocarpus frondosus seedlings under different levels of shade in the field. The treatments used were: 0 % (full sun); 18 %; 50 % and 70 % shading in a randomized block design. The survival of seedlings was evaluated 30 and 540 days after planting (d.a.p.) and the morphological attributes height (H), stem diameter (DC) and H / DC ratio every 90 days. Leaf area, leaf dry matter, dry matter of stem and branches and dry matter of shoot were obtained 540 d.a.p. The analyses of the physiological attributes fluorescence of chlorophyll a and photosynthetic pigments were performed 180, 360 and 540 d.a.p. The use of shading in the planting of Myrocarpus frondosus influences the survival and the morphological and physiological attributes of the species. The morphological and physiological attributes of Myrocarpus frondosus plants show that the species requires shading of 50 to 70 % in its initial growth phase in the field (540 d.a.p.). It is recommended to use the species in sub-forest enrichment plantations and in consortium with other species more demanding in light.
“…Las imágenes fueron procesadas con la ayuda de software Image J. Posteriormente el material fue acondicionado en bolsas de papel tipo Kraft y llevado a una estufa con circulación de aire a 65°C hasta alcanzar peso constante y, posteriormente pesadas en balanza analítica, para la determinación de la MSF, MSTR y MSPA. El AF fue obtenida de acuerdo a adaptaciones de la metodología de Coelho-Filho et al (2012), utilizando la siguiente fórmula:…”
Light is an important environmental factor in the establishment of vegetation. The knowledge of the behavior of the species in response to light demand for survival and growth in the field becomes essential. Thus, the present study aimed at evaluating the survival and initial growth of Myrocarpus frondosus seedlings under different levels of shade in the field. The treatments used were: 0 % (full sun); 18 %; 50 % and 70 % shading in a randomized block design. The survival of seedlings was evaluated 30 and 540 days after planting (d.a.p.) and the morphological attributes height (H), stem diameter (DC) and H / DC ratio every 90 days. Leaf area, leaf dry matter, dry matter of stem and branches and dry matter of shoot were obtained 540 d.a.p. The analyses of the physiological attributes fluorescence of chlorophyll a and photosynthetic pigments were performed 180, 360 and 540 d.a.p. The use of shading in the planting of Myrocarpus frondosus influences the survival and the morphological and physiological attributes of the species. The morphological and physiological attributes of Myrocarpus frondosus plants show that the species requires shading of 50 to 70 % in its initial growth phase in the field (540 d.a.p.). It is recommended to use the species in sub-forest enrichment plantations and in consortium with other species more demanding in light.
“…The leaf area index (AFI) is an important variable when evaluating the growth, development and possible productivity of a crop (Taiz & Zeiger, 2013) besides presenting regarding water need for irrigation purposes (Posse et al, 2009;Busato et al, 2010;Coelho Filho et al, 2012).…”
The leaf area index (AFI) is an important variable when evaluating the growth, development and possible productivity of a crop. The objective of this article was to determine mathematical models that allow estimating the leaf area of tobacco from measurements of dimensions of length and width of tobacco leaves. The experimental design used was in blocks with four replications and two planting times. The treatments consisted of five commercial cultivars of Virginia type tobacco and Burley type. Of which the leaves were detached from the stem, and these leaves were fractionated in limbo and petiole. Its leaves were 10 models were obtained to estimate the leaf area of tobacco. All the models presented a significant test to estimate the leaf area. The power and quadratic models presented values of determination coefficients higher than linear models. It had the best results with the nonlinear power and quadratic model, using the squared width multiplied by length. Therefore, the measurements of the leaf area of tobacco can be estimated from potential, linear and quadratic equations with good precision. The models that use linear squared width measurements multiplied by leaf limbo length satisfactorily estimate the leaf area of tobacco.
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