Hongos fitopatógenos asociados a la enfermedad de marchitez vascular y muerte regresiva en plantaciones de Tectona grandis L.f. (teca) en el Trópico Húmedo Ecuatoriano

Plantaciones de teca (Tectona grandis L. f.) en Ecuador están siendo afectadas por una compleja enfermedad de marchites vascular y muerte regresiva, con características epidémicas, sin que hasta el momento se conozca el o los agentes causales. Se planteó describir la sintomatología de la enfermedad e identificar los hongos fitopatógenos asociados a árboles enfermos en el Trópico Húmedo Ecuatoriano. Se seleccionaron tres plantaciones de 2, 5 y 7 años de edad, en cada una se delimitó tres parcelas de 500 m2. Se realizó la descripción sintomatológica, evaluó la incidencia y severidad de la enfermedad empleando una escala de cinco categorías. Por parcela se diseccionaron tres árboles, cuyos tejidos se llevaron al laboratorio, donde se emplearon tres estrategias metodológicas (cámara húmeda, sanduches de zanahoria, y medio de cultivo papa-dextrosa-agar; PDA) para estimular la expresión de los fitopatógenos. En árboles enfermos se detectó clorosis, pérdida de turgencia, ápices de crecimiento secos, emisión de brotes epicormicos en el fuste, y marchitez fulminante. Se aisló e identificó Ceratocystis fimbriata Ellis & Halst., y Fusarium sp. de forma consecutiva con las tres estrategias metodológicas empleadas. La incidencia de la enfermedad fue del 16.6%, 15.2%, y 11.6% para las plantaciones de 2, 5 y 7 años, respectivamente. Los árboles enfermos en la plantación de 2 años se encontraron en las escalas 2, 4 y 5, mientras que en plantaciones de 5 y 7 años se ubicaron en las escalas 2, 3 y 5 de progreso de la enfermedad

Acumulación De Restos Lignino-Celulósicos (Necromasa) En Un Bosque Templado De Antiguo Crecimiento Dominado Por Nothofagus En El Centro- Sur De Chile

Coarse woody debris (CWD) are the necromass in wooded environments and comply with various ecosystems functions, such as seedling nursery, habitat other organisms, store carbon (C) and nutrients, etc.. Volume, necromass, and decay states of CWD dead in an old-growth temperate (OGTF) forest in Puyehue National Park, South-Central Chile were evaluated. In 10 plots of 900 m2 CWD was quantified (≥ 10 cm diameter), whose necromass classified using a scale of five categories/stages of decay, necromass (1 = lowest and 5 = highest degradation). The average forest density was 299 trees ha-1, 112 m2 ha-1 of basal area, and 2.395 m3 of stem volume. The upper arboreal stratum was dominated by N. betuloides. The greatest amount of CWD belonged to N. betuloides (95,2%), where logs (52,7%) and branches (35%), plant structures were present in greater numbers. The bulk of necromass found in advanced states of decomposition (level 4 and 5) with 56,5% and 34,1%, respectively. It was determined that the CWD volume was 632 m3 ha-1, representing a necromass of 321.5 Mg ha- 1. These results demonstrate that the old-growth temperate forests of southern Chile are significant reserves of coarse woody debris, which contributes to the biogeochemistry of these complex and remote ecosystems

Contenidos De Celulosa Y Lignina En Restos Lignino- Celulósicos De Gran Tamaño (Necromasa) En Un Bosque Templado De Antiguo Crecimiento Del Centro-Sur de Chile

The evaluation of volume, necromass, states of decay, solubility, and cellulose and lignin content in coarse woody debris (RLC) accumulated in an evergreen temperate forest of old-growth in the Puyehue National Park, South-Central Chile. Ten plots of 900 m2 each, were quantified for RLC (≥ 10 cm diameter). For necromass quantification was used a scale of five categories/states of decay, necromass (1 = lowest and 5 = highest degradation). 632 m3 ha-1 of deadwood (= 231,5 Mg ha-1 of necromass) was found, mainly represented by Nothofagus betuloides (95,2%). The wood with the most advanced state of decay (state 5) showed a greater solubility, increasing of 273,7 and 818,6 times more soluble than 1, for N. betuloides and S. conspicua, respectively. Cellulose content decreased to 91%, while the lignin increased 248% and 142% in wood decay of N. betuloides and S. conspicua, respectively. These results demonstrate the importance of RLC in the biogeochemistry of remote forest ecosystems of old-growth in Southern Chile

Ecuaciones alométricas para estimar tasas de crecimiento de Myroxylon balsamum, Minquartia guianensis y Otoba parvifolia en la Amazonía ecuatoriana

The evaluation of the analysis of the growth rates of the forest species Myroxylon balsamum (L.) Harms (Balsamo) and Minquartia guianensis Aubl. (Guayacan negro) and Otoba parvifolia (Doncel), established in research stands at the Jatun Sacha Science Station (JSSS), at the age of 20, was the main reason for this research. According to the results obtained it was found that the Balsamo needs 59 years to reach the 60 centimeters of Minimum Cutting Diameter (DMC) that is determined by Ministerial Agreement 039 of the Ministry of the Environment, the Guayacán Negro Huambula, needs 69 years to arrive To the 40 centimeters of diameter, whereas the Doncel needs 27 years to obtain 50 cm of diameter.La evaluación del análisis de las tasas de crecimiento de las especies forestales Myroxylon balsamum (L.) Harms (Bálsamo) y Minquartia guianensis Aubl. (Guayacán negro) y Otoba parvifolia (Doncel) establecidas en rodales de investigación en la Estación Científica Jatun Sacha (ECJS), con una edad de 20 años, fue el motivo principal de esta investigación. De acuerdo a los resultados obtenidos se encontró que el Bálsamo necesita 59 años para alcanzar los 60 centímetros de Diámetro Mínimo de Corta (DMC), que está determinado por el Acuerdo Ministerial 039 del Ministerio del Ambiente, el Guayacán negro Huambula, necesita 69 años para llegar a los 40 centímetros de diámetro, mientras que el Doncel necesita 27 años para obtener 50 cm de diámetro

Entrepreneurship and innovation in a competition context

International audienceThe objective of this research is to explore the relationship between the competitive situation and the launching strategy of a new product. It also aims to study the internal structure of the competitive situation. Competition situation is apprehended with 4 variables: strategic similarity, multimarket competition, market concentration and competition intensity (the first three being perceived as antecedents of the last). Launching strategy, strategic similarity and competition intensity have two internal dimensions: a strategic and a tactical one. Using a questionnaire, data was collected from 140 managers involved in the recent launching of a new product in France. The findings onfirmed that competition intensity depends partially on other variables of the competition situation, and that the latter exert an influence on the structure of the launching strategy. These relations vary considerably, according to the sub-dimensions of the variables. However, other antecedents of competition intensity on the one hand and of the launching strategy structure on the other hand, are to be sought beyond the simple competition situatio

Calidad del agua destinada al consumo humano en un cantón de Ecuador

The study evaluated the quality of water intended for human consumption in the canton Quevedo, province of Los Rios, Ecuador. Physical, chemical and microbiological parameters of water in nine EPMAPAQ pumping stations were evaluated, in rainy and dry seasons. The results obtained with the reference values set out in the regulations (Ministerial Agreement No. 097 Standard INEN 1108, TULSMA, EPA and WHO) under the quality criterion for water intended for human consumption and domestic use was compared. The Water Quality Index (ICA) and the statistical correlation between parameters were determined using the test "t" of Student, with a statistical significance of p = 0.05 between the two periods. Parameters: nitrites, nitrates, turbidity, total dissolved solids, pH, total hardness, color and iron are in the range of acceptability environmental quality. Values, manganese, dissolved oxygen exceed the maximum permissible limits for the TULSMA, like fecal coliform in the rainy season. Most parameters showed significant differences ("t" 5%) between the two periods. Quevedo Canton water is slightly contaminated and requires purification treatment before consumption