Page 1. 39 Rev. Forest. Venez. 44(2) 2000, 39-48 ESTUDIO ANATÓMICO DEL LEÑO DE SEIS ESPECIES DE L... more Page 1. 39 Rev. Forest. Venez. 44(2) 2000, 39-48 ESTUDIO ANATÓMICO DEL LEÑO DE SEIS ESPECIES DE LIANAS Osmary Z. Araque, Narcisana Espinoza de Pernía y Williams J. León H. Universidad de Los Andes, Facultad ...
Por primera vez se reporta, formalmente, a Fusarium oxysporum como agente causal de pudrición neg... more Por primera vez se reporta, formalmente, a Fusarium oxysporum como agente causal de pudrición negra basal en pardillo negro. Los árboles enfermos primeramente se marchitan y posteriormente mueren súbitamente a causa de la invasión y descomposición de raíces y los tejidos que conforman la porción inferior del tronco. Considerando la severidad del ataque y lo difícil que resulta controlar eficientemente las especies de Fusarium, se puede presumir que la enfermedad investigada pudiera convertirse en un importante factor limitante para empleo del pardillo negro como árbol de sombra en plantaciones de cacao. ABSTRACT Cedeño, L. and Araque, O. 2010. Basal black rot disease caused by Fusarium oxysporum on pardillo negro (Cordia thalsiana). Fitopatol. Venez. 23:2-4.
Mecanografiado Informe de pasantías (Ing. Forestal)-- Universidad de Los Andes, Facultad de Cienc... more Mecanografiado Informe de pasantías (Ing. Forestal)-- Universidad de Los Andes, Facultad de Ciencias Forestales y Ambientales, Escuela de Ingeniería Forestal, Mérida, 1999 Incluye bibliografía
Journal of Agriculture and Rural Development in the Tropics and Subtropics
In recent times, increased emphasis has been placed on diversifying the types of trees to shade c... more In recent times, increased emphasis has been placed on diversifying the types of trees to shade cacao (Theobroma cacao L.) and to achieve additional services. Agroforestry systems that include profitable and native timber trees are a viable alternative but it is necessary to understand the growth characteristics of these species under different environmental conditions. Thus, timber tree species selection should be based on plant responses to biotic and abiotic factors. The aims of this study were (1) to evaluate growth rates and leaf area index of the four commercial timber species: Cordia thaisiana, Cedrela odorata, Swietenia macrophylla and Tabebuia rosea in conjunction with incidence of insect attacks and (2) to compare growth rates of four Venezuelan Criollo cacao cultivars planted under the shade of these four timber species during the first 36 months after establishment. Parameters monitored in timber trees were: survival rates, growth rates expressed as height and diameter a...
SUMMARYWe studied physiological traits of 12 Criollo cocoa cultivars growing in a germplasm bank ... more SUMMARYWe studied physiological traits of 12 Criollo cocoa cultivars growing in a germplasm bank in the southern region of Maracaibo Lake Basin, during the rainy (RS) and dry seasons (DS) of 2007. A further evaluation of photosynthetic responses to changes in environmental parameters was done on three cultivars: Los Caños 001 (LCA001), Sur Porcelana 010 (SP010) and Escalante 001 (ESC001) in 2009 and 2010. Leaf water potential (ΨL) of most cultivars decreased during the DS of 2007, with the exception of ESC001. Maximum photosynthetic rate (Amax), stomatal conductance and water use efficiency varied among cultivars and seasons. The CO2-saturated photosynthetic rate (ACO2sat) was higher in LCA001 and ESC001 than in SP010, with no differences in carboxylation efficiency. Light curve responses of the three cultivars were similar. In all cultivars, no evidence of chronic photoinhibition was observed, since maximum quantum yield of photosystem II was high (0.77–0.81). We conclude that ESC0...
The wood anatomy study of eleven lianas species from Bignoniaceae family reported in the Caparo F... more The wood anatomy study of eleven lianas species from Bignoniaceae family reported in the Caparo Forest Reserve (Barinas state, Venezuela) is presented: Anemopaegma chrysoleu- cum, Arrabidaea candicans, A. verrucosa, Ceratophytum tetragonolobum, Cydista aequinoc- tialis, Macfadyena uncata, M. unguis-cati, Paragonia pyramidata, Pithecoctenium cru- cigerum, Phryganocydia corymbosa and Xylophragma seemannianum. The species were included in two groups: species with two-sized rays and
SUMMARYThis study deals with the ecophysiological response of Criollo cacao cultivars to water de... more SUMMARYThis study deals with the ecophysiological response of Criollo cacao cultivars to water deficit during initial establishment phase in an agroforestry system under shade of four timber species using a randomised block design. CO2 assimilation rate (A), transpiration (E) and stomatal conductance (gs), water potentials, pressure–volume curves and fluorescence measurements were studied during two dry and wet seasons. Survival rates, basal diameter and leaf concentrations of K, P and N were also determined. All cultivars exhibited 60% reduction in gs with drought, resulting in 73% decrease in A and E. Despite lower A, electron-transport rates were not significantly affected, suggesting the existence of electron sinks. Photochemical quenching is negatively affected by drought in some cultivars, whereas relative quantum yield of photosystem II and non-photochemical quenching remained the same during both the periods. Cultivars with the highest osmotic adjustment coincided with the h...
Page 1. 39 Rev. Forest. Venez. 44(2) 2000, 39-48 ESTUDIO ANATÓMICO DEL LEÑO DE SEIS ESPECIES DE L... more Page 1. 39 Rev. Forest. Venez. 44(2) 2000, 39-48 ESTUDIO ANATÓMICO DEL LEÑO DE SEIS ESPECIES DE LIANAS Osmary Z. Araque, Narcisana Espinoza de Pernía y Williams J. León H. Universidad de Los Andes, Facultad ...
Por primera vez se reporta, formalmente, a Fusarium oxysporum como agente causal de pudrición neg... more Por primera vez se reporta, formalmente, a Fusarium oxysporum como agente causal de pudrición negra basal en pardillo negro. Los árboles enfermos primeramente se marchitan y posteriormente mueren súbitamente a causa de la invasión y descomposición de raíces y los tejidos que conforman la porción inferior del tronco. Considerando la severidad del ataque y lo difícil que resulta controlar eficientemente las especies de Fusarium, se puede presumir que la enfermedad investigada pudiera convertirse en un importante factor limitante para empleo del pardillo negro como árbol de sombra en plantaciones de cacao. ABSTRACT Cedeño, L. and Araque, O. 2010. Basal black rot disease caused by Fusarium oxysporum on pardillo negro (Cordia thalsiana). Fitopatol. Venez. 23:2-4.
Mecanografiado Informe de pasantías (Ing. Forestal)-- Universidad de Los Andes, Facultad de Cienc... more Mecanografiado Informe de pasantías (Ing. Forestal)-- Universidad de Los Andes, Facultad de Ciencias Forestales y Ambientales, Escuela de Ingeniería Forestal, Mérida, 1999 Incluye bibliografía
Journal of Agriculture and Rural Development in the Tropics and Subtropics
In recent times, increased emphasis has been placed on diversifying the types of trees to shade c... more In recent times, increased emphasis has been placed on diversifying the types of trees to shade cacao (Theobroma cacao L.) and to achieve additional services. Agroforestry systems that include profitable and native timber trees are a viable alternative but it is necessary to understand the growth characteristics of these species under different environmental conditions. Thus, timber tree species selection should be based on plant responses to biotic and abiotic factors. The aims of this study were (1) to evaluate growth rates and leaf area index of the four commercial timber species: Cordia thaisiana, Cedrela odorata, Swietenia macrophylla and Tabebuia rosea in conjunction with incidence of insect attacks and (2) to compare growth rates of four Venezuelan Criollo cacao cultivars planted under the shade of these four timber species during the first 36 months after establishment. Parameters monitored in timber trees were: survival rates, growth rates expressed as height and diameter a...
SUMMARYWe studied physiological traits of 12 Criollo cocoa cultivars growing in a germplasm bank ... more SUMMARYWe studied physiological traits of 12 Criollo cocoa cultivars growing in a germplasm bank in the southern region of Maracaibo Lake Basin, during the rainy (RS) and dry seasons (DS) of 2007. A further evaluation of photosynthetic responses to changes in environmental parameters was done on three cultivars: Los Caños 001 (LCA001), Sur Porcelana 010 (SP010) and Escalante 001 (ESC001) in 2009 and 2010. Leaf water potential (ΨL) of most cultivars decreased during the DS of 2007, with the exception of ESC001. Maximum photosynthetic rate (Amax), stomatal conductance and water use efficiency varied among cultivars and seasons. The CO2-saturated photosynthetic rate (ACO2sat) was higher in LCA001 and ESC001 than in SP010, with no differences in carboxylation efficiency. Light curve responses of the three cultivars were similar. In all cultivars, no evidence of chronic photoinhibition was observed, since maximum quantum yield of photosystem II was high (0.77–0.81). We conclude that ESC0...
The wood anatomy study of eleven lianas species from Bignoniaceae family reported in the Caparo F... more The wood anatomy study of eleven lianas species from Bignoniaceae family reported in the Caparo Forest Reserve (Barinas state, Venezuela) is presented: Anemopaegma chrysoleu- cum, Arrabidaea candicans, A. verrucosa, Ceratophytum tetragonolobum, Cydista aequinoc- tialis, Macfadyena uncata, M. unguis-cati, Paragonia pyramidata, Pithecoctenium cru- cigerum, Phryganocydia corymbosa and Xylophragma seemannianum. The species were included in two groups: species with two-sized rays and
SUMMARYThis study deals with the ecophysiological response of Criollo cacao cultivars to water de... more SUMMARYThis study deals with the ecophysiological response of Criollo cacao cultivars to water deficit during initial establishment phase in an agroforestry system under shade of four timber species using a randomised block design. CO2 assimilation rate (A), transpiration (E) and stomatal conductance (gs), water potentials, pressure–volume curves and fluorescence measurements were studied during two dry and wet seasons. Survival rates, basal diameter and leaf concentrations of K, P and N were also determined. All cultivars exhibited 60% reduction in gs with drought, resulting in 73% decrease in A and E. Despite lower A, electron-transport rates were not significantly affected, suggesting the existence of electron sinks. Photochemical quenching is negatively affected by drought in some cultivars, whereas relative quantum yield of photosystem II and non-photochemical quenching remained the same during both the periods. Cultivars with the highest osmotic adjustment coincided with the h...
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