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Vegetative and productive aspects of organically grown coffee cultivars under shaded and unshaded systems
Ricci, Marta dos Santos Freire;Rouws, Janaina Ribeiro Costa;Oliveira, Nelson Geraldo de;Rodrigues, Marinete Bezerra;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000400006
Abstract: although coffea arabica species has its origin in the african understories, there is great resistance on the part of the brazilian producers for growing this species under agroforestry systems as they fear that shading reduces production. this study aimed at evaluating some vegetative traits and the productivity of organically grown coffee (coffea arabica l.) cultivars under shaded and unshaded systems. twelve treatments consisting of two cultivation systems (shaded and unshaded) and six coffee cultivars were arranged in randomized blocks with four replicates, in a split-plot scheme. shading was provided by banana (musa sp.) and coral bean plants (erythrinaverna). shading delayed fruit maturation. late maturation cultivars, such as the icatu and the obat?, matured early in both cultivation systems, while medium and early maturation cultivars presented late maturation. cultivation in the shaded system increased the leaf area and the number of lower branches, decreased the number of productive nodes per branch, and increased the distance between the nodes and the number of leaves present in the branches. cultivation in the unshaded system presented greater number of plants with branch blight in relation to plants grown in the shade. the productivity of the cultivars was not different, at 30.0 processed bags per hectare in the shaded system, and 25.8 processed bags per hectare in the unshaded system. the most productive cultivars in the shaded system were the tupi, the obat?, and the catuaí, while no differences between cultivars were obtained in the unshaded system.
Descomposición y liberación de nutrimentos desde las raíces finas de los sistemas agroforestales de cacao con sombras de poró y laurel, en Turrialba, Costa Rica Descomposición y liberación de nutrimentos desde las raíces finas de los sistemas agroforestales de cacao con sombras de poró y laurel, en Turrialba, Costa Rica  [cached]
Mu?oz Arboleda Fernando
Acta Agronómica , 2006,
Abstract: Se usó el método de bolsas de descomposición para estudiar la pérdida de biomasa y liberación de N, P, K, Ca y Mg desde las raíces finas (<2 mm) en los sistemas agroforestales de cacao con sombras de poró y laurel. Se muestrearon bolsas a las 1, 2, 4, 6, 12, 18 y 25 semanas en las épocas seca y lluviosa. Las tasas de descomposición y liberación de nutrimentos fueron bien descritas por un modelo exponencial doble. Se observó alta relación entre las tasas de pérdida de biomasa y liberación de N de las tres especies. Las tasas de liberación de nutrimentos fueron K > Mg > P > N > Ca. Después de una semana de incubación cerca del 90% del K fue liberado mientras que el Ca tendió a la acumulación. Las raíces de poró fueron las de más rápida descomposición y liberación de nutrimentos, excepto de K. El poró sería la especie de sombra adecuada para sistemas de producción que requieran rápida recirculación de nutrimentos. El laurel exhibió tasas lentas de descomposición y liberación de nutrimentos. Palabras claves: Agroforestería, Theobroma cacao, Erythrina poeppigiana, Cordia alliodora, recirculación de nutrimentos, descomposición de raíces finas.
The use of the shaded coffee (sombrío del cafeto) production thecnique (Coffea arabica) in colombia Aplicación del sombrío del cafeto (Coffea arabica) en Colombia  [cached]
Gonzalo Enrique Mancilla Díaz
Conexión Agropecuaria JDC , 2012,
Abstract: The art of coffee production under shade has been one of the most effective methods used by our ancestors in order to adapt the coffee trees to precarious conditions, where they would not otherwise produce profitably due to the conditions of elevation, light, water availability, percentage of organic matter, temperature and other climatic and geographic factors. The objective of this study was to explain in a consistent and clear way the interaction of different effects generated in the soil, atmosphere and the crop, as a result of the use of the shaded coffee technique (sombrío de café) in coffee plantations. This provides tools that are applicable to the Colombian coffee growing industry, which can produce an improvement in the use of this technique, based on the zoning of the productive unit. This will generate an increase in the life and productivity of the crop. La técnica de producción de café bajo sombrío ha sido uno de los métodos más utilizados por nuestros ancestros con el fin de adaptar las plantas de cafeto a condiciones precarias donde no producirían rentablemente debido a las condiciones de altimetría, luminosidad, disponibilidad de agua, porcentaje de materia orgánica y temperatura, entre otros factores climáticos y geográficos. El siguiente trabajo de revisión se realizó con el objetivo de explicar de manera clara y concisa la interacción de los diferentes efectos generados en el suelo, la atmósfera y el cultivo, a partir de la aplicación del sombrío en los cafetales; brindando herramientas aplicables a la caficultura colombiana, con el fin de mejorar la aplicación de esta técnica dependiendo de la zonificación de la unidad productiva y, por ende, aumentando la vida útil y productividad del cultivo.
DEPENDENCIA MICORRIZAL DE LAUREL (Ocotea sp.)
Sierra-Escobar,Jorge A.; Castro Restrepo,Dagoberto; Osorio Vega,Walter;
Colombia Forestal , 2009,
Abstract: a greenhouse experiment was carried out to determine the mycorrhizal dependency of laurel (>ocotea sp.). in order to do this, a completely randomized experimental design was used, with six treatments in a factorial array of 3x2 and five repetitions. the treatments involved a combination of three phosphorus (p) levels in soil solution (0.002, 0.02 and 0.2 mg l-1) and two levels of mycorrhizal inoculation, either inoculated or non-inoculated with glomus aggregatum schenck & smith. the leaf p content as a function of time was used as an output variable. shoot dry matter, shoot p content, mycorrhizal colonization of roots, and mycorrhizal dependence were measured at harvest. the results indicated that the leaf p content increased significantly when using the mycorrhizal inoculation in laurel at p level 0.2 mg l -1, but not in the other p levels, on some of the sampling days. shoot dry weight and total plant p content did not increase at all levels of soil available p. mycorrhizal dependency of laurel reached 28%, which allows this species to be classified as moderately dependent on mycorrhiza.
Distribución espacio-temporal de hormigas en un gradiente de luz, dentro de un sistema agroforestal de café, en Turrialba, Costa Rica
Varón,Edgar H; Hanson,Paul; Longino,John T; Borbón,Olger; Carballo,Manuel; Hilje,Luko;
Revista de Biología Tropical , 2007,
Abstract: temporal and spatial distribution of ants in a light gradient, in a coffee agroforestry system, turrialba, costa rica. shade trees are frequently present in coffee (coffea arabica l.) agroforestry systems of mesoamerica. these systems can harbor a rich entomofauna, including ants, which could be predators of key pests in these systems. however, the role of shade on the distribution and abundance of these ants is unknown, yet such knowledge could suggest guidelines for manipulating certain environmental conditions of their habitat, thereby achieving their conservation and increase. therefore, we studied the effect of shade on the spatial and temporal distribution of three ant species (solenopsis geminata, pheidole radoszkowskii and crematogaster curvispinosa) that may prey on the coffee berry borer, hypothenemus hampei (coleoptera: scolytidae), and the mahogany shootborer, hypsipyla grandella (lepidoptera: pyralidae). to do this, abundance was evaluated across a sun-shade gradient in a coffee plantation with four alternate plots (from pure sun to total shade) in turrialba, costa rica. in the community that was studied 28 species of ants were collected, of which s. geminata was the dominant species (79 % of the total individuals), followed by p. radoszkowskii (16 %). s. geminata and c. curvispinosa preferred sunny areas, while p. radoszkowskii showed no defined preference. likewise, with respect to location, s. geminata predominated in the soil, while p. radoszkowskii and c. curvispinosa predominated in coffee bushes. rev. biol. trop. 55 (3-4): 943-956. epub 2007 december, 28.
Coffee biotechnology
De Los Santos-Briones, César;Hernández-Sotomayor, S. M. Teresa;
Brazilian Journal of Plant Physiology , 2006, DOI: 10.1590/S1677-04202006000100015
Abstract: in the last three decades, interest has turned to in vitro cell culture in different areas of coffee research. in vitro techniques have been applied not only for coffee improvement through genetic transformation but also to study various aspects in coffee cells such as chemical (caffeine synthesis and the production of coffee aroma), physiological and more recently, biochemical aspects. the most important advances obtained to date on in vitro coffee techniques in fields like biochemistry, physiology, regeneration systems and genetic engineering, are presented and discussed.
Volatile constituents of the leaves of Siparuna thecaphora (Siparunaceae) from Turrialba, Costa Rica
Cicció,José F.; Gómez-Laurito,Jorge;
Revista de Biología Tropical , 2002,
Abstract: the composition of the essential oil from leaves of siparuna thecaphora (poepp. et endl.) a. dc. collected in turrialba, costa rica, was determined by capillary gc/ms. seventy-six compounds were identified corresponding to ca. 95% of the oil. the major components were germacrene d (32.7%), α-pinene (16.3%), β - pinene (13.8%) and β -caryophyllene (4.1%). thirty-one minor compounds were identified for the first time in this genus of plants.
Susceptibilidad al deslizamiento en el corredor Siquirres-Turrialba Landslide susceptibility in the Siquirres-Turrialba corridor  [cached]
Gustavo Segura,Elena Badilla,Luis Obando
Revista Geológica de América Central , 2011,
Abstract: Se presenta una zonificación de la susceptibilidad al deslizamiento en el sector entre las localidades de Siquirres y Turrialba, específicamente para un corredor de 10 km de ancho sobre la ruta del poliducto de RECOPE, que cubre una extensión aproximada de 330 km2. El estudio se realizó a partir de la interpretación de fotografías aéreas, información bibliográfica y la aplicación del método Mora & Vahrson (Mora et al., 1992), sustituyendo el relieve relativo por un mapa de pendientes e incorporando un mapa inventario de deslizamientos en la evaluación del parámetro de susceptibilidad litológica. Como resultado de la zonificación, se obtuvo que las áreas correspondientes a susceptibilidad baja abarcan la mayor parte del mapa (33,9%) y se presentan mayormente en sectores donde afloran las unidades litoestratigráficas Tuis, al sureste del área, Suretka y en algunos sectores de la formación Andesitas Poás. Las áreas correspondientes a susceptibilidad media (25,3%) se presentan principalmente en rocas de las formaciones Andesitas Poás, Uscari y Guayacán; mientras que las áreas correspondientes a susceptibilidad alta (13,4%) se presentan principalmente en sectores donde afloran las rocas de las formaciones Andesitas Poás, Uscari, Brechas La Unión y Río Banano. A landslide suceptibility zonation was performed in a 10 km wide corridor along the RECOPE pipeline between the cites of Siquirres and Turrialba. The total study area is 330 km2. Analysis was based on aerial photointerpretation, bibliographic research and the application of the Mora-Vahrson method (Mora et al., 1992), in which slope was used instead of the internal relief parameter. A landslide inventory map was included in the evaluation of the lithological suceptibility parameter. Zonation resulted in a predominance of areas with low landslide susceptibility (33,9%), mostly located where Tuis Formation is present, south east of the study area, followed by Suretka Formation and partially Andesitas Poás.
Coffee carbohydrates
Redgwell, Robert;Fischer, Monica;
Brazilian Journal of Plant Physiology , 2006, DOI: 10.1590/S1677-04202006000100012
Abstract: this review summarises recent advances in the chemistry, physiology and molecular properties of coffee carbohydrates with a particular focus on the cell wall polysaccharides. the results of detailed chemical studies have demonstrated novel structural features of both the galactomannans and the arabinogalactan polysaccharides of the green and roasted coffee bean. for the first time immunological probes based on monoclonal antibodies for specific polysaccharide epitopes were used to reveal the patterns of distribution of the galactomannans, arabinogalactans and pectic polysaccharides in the coffee bean cell wall. finally, the results of physiological and molecular studies are presented which emphasise the growing awareness of the potential role the metabolic status of the green bean may play in final coffee beverage quality.
Laurel: A Hybrid Overlay Network for Data Distribution
Laurel:一种混合式数据分发覆盖网

ZHENG Zhong,WANG Yi-Jie,MA Xing-Kong,
郑重
,王意洁,马行空

软件学报 , 2011,
Abstract: As an infrastructure for data distribution, overlay networks must incorporate efficient routing and adequate robustness in order to achieve fast and accurate data distribution in an environment with a high node churn. Considering that the existing overlay networks mostly focus on a single optimization objective and fail to ensure routing efficiency and robustness. Simultaneously, a hybrid overlay network for data distribution, Laurel, is proposed in this paper. Laurel achieves a better trade-off between routing efficiency and robustness by combining the inter-cluster multiple structured topologies with the intra-cluster unstructured topologies. Laurel also provides mechanisms for a dynamic, concurrent cluster creation, cluster departure, and load balance to make data distribution more adaptive to the dynamic network environment. Experimental results show that compared with existing overlay networks, Laurel can support faster and more accurate data distribution, even when a large amount of nodes fail in the system and balance the load within clusters.
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