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Search Results: 1 - 10 of 7628 matches for " Jaime Mena-Covarrubias "
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Rendimiento y calidad de chile seco 'Mirasol' cultivado bajo riego parcial de la raíz
Serna-Pérez, Alfonso;Zegbe, Jorge Artemio;Mena-Covarrubias, Jaime;
Revista Chapingo. Serie horticultura , 2011,
Abstract: the efficient use of water resources is mandatory for the dry chili producing area of zacatecas. the objective of this study was to compare two types of partial rootzone drying (prd) against commercial irrigation (ci) in relation to yield and fruit quality, irrigation water use efficiency (iwue), and pepper wilt incidence (wi) of chilli cv. 'mirasol'. prd treatments were prd50 on which 50% of ci was applied alternately to both sides of the root zone, and prd50+20 which was similar to prd50, but additionally 20% of ci was applied to the drying side of the root system. prd50 and prd50+20 promoted water savings compared with ci. the fruit quality categories of dry chili and yield were similar among treatments, but yield tended to decrease in prd50 and prd50+20 in 2009. the iwue tended to increase in prd50 and prd50+20 relative to ci. in 2008 wi was the same among treatments, but in 2009 it increased in the prd treatments. soil water saturation by continuous precipitations after irrigation events partially explained the increase in wi, and therefore the reduction in yield in the 2009. nevertheless, prd50 tended to increase iwue by 28 % and to reduce the volume of water applied by 32 % with respect to ci. therefore, the rpr is a promising strategy for sustainability of this production system.
Incidencia y sintomatología de cinco virus en parcelas comerciales de chile seco en Aguascalientes, San Luis Potosí y Zacatecas, México
Velásquez-Valle, Rodolfo;Reveles-Torres, Luis Roberto;Mena-Covarrubias, Jaime;
Revista mexicana de ciencias agrícolas , 2012,
Abstract: world-wide the chili pepper crop is affected by more than 60 viral diseases, although very little is known about them in the area of dry pepper plantation in northern-central mexico. consequently, the aims of this work were to identify the presence of the virus and the associated symptoms in commercial dry pepper fields of the states of zacatecas, san luis potosí, and aguascalientes, mexico. mirasol and ancho pepper plants were sampled and the presence of symptoms such as dwarfing, chlorosis, leaf deformation, defoliation, vascular necrosis and joined branches, were recorded. samples were analyzed using das-elisa with the antisera of the tobacco mosaic virus (tobacco mosaic virus: tmv), cucumber mosaic virus (cucumber mosaic virus: cmv), potato virus y (potato virus y: pvy), pepper mottle virus (pepper mottle virus: pepmov), and tobacco etch virus (tobacco etch virus: tev). these viruses were identified in pepper plants collected in dry pepper fields located in the three states mentioned earlier.
Incidencia y sintomatología de cinco virus en parcelas comerciales de chile seco en Aguascalientes, San Luis Potosí y Zacatecas, México Incidence and symptomatology of five viruses in commercial dry chili pepper fields in Aguascalientes, San Luis Potosí, and Zacatecas, Mexico
Rodolfo Velásquez-Valle,Luis Roberto Reveles-Torres,Jaime Mena-Covarrubias
Revista mexicana de ciencias agrícolas , 2012,
Abstract: A nivel mundial el cultivo de chile es afectado por más de 60 enfermedades virales; sin embargo, poco se conoce acerca de ellas en el área productora de chile seco del norte centro de México por lo que el objetivo del presente trabajo consistió en detectar la presencia y sintomatología de cinco virus en parcelas comerciales de chile seco en los estados mencionados. Plantas de chile de los tipos mirasol y ancho fueron muestreadas y se anotó la presencia de síntomas como enanismo, clorosis, deformación de hojas, defoliación, necrosis vascular y ramas unidas. Las muestras fueron analizadas mediante la técnica DAS-ELISA empleando los antisueros para el virus del mosaico del tabaco (Tobacco mosaic virus: TMV), mosaico del pepino (Cucumber mosaic virus: CMV), Y de la papa (Potato virus Y: PVY), moteado del chile (Pepper mottle virus: PepMoV) y jaspeado del tabaco (Tobacco etch virus: TEV). Esos virus fueron identificados en plantas de chile colectadas en las parcelas comerciales de chile seco de los tres estados antes mencionados. World-wide the chili pepper crop is affected by more than 60 viral diseases, although very little is known about them in the area of dry pepper plantation in northern-central Mexico. Consequently, the aims of this work were to identify the presence of the virus and the associated symptoms in commercial dry pepper fields of the states of Zacatecas, San Luis Potosí, and Aguascalientes, Mexico. Mirasol and ancho pepper plants were sampled and the presence of symptoms such as dwarfing, chlorosis, leaf deformation, defoliation, vascular necrosis and joined branches, were recorded. Samples were analyzed using DAS-ELISA with the antisera of the tobacco mosaic virus (Tobacco mosaic virus: TMV), cucumber mosaic virus (Cucumber mosaic virus: CMV), potato virus Y (Potato virus Y: PVY), pepper mottle virus (Pepper mottle virus: PepMoV), and tobacco etch virus (Tobacco etch virus: TEV). These viruses were identified in pepper plants collected in dry pepper fields located in the three states mentioned earlier.
Retraso de la cosecha en nopal tunero cv. Cristalina
Zegbe, J. A.;Mena-Covarrubias, J.;
Revista Chapingo. Serie horticultura , 2008,
Abstract: cactus pear fruit prices drop significantly during august and september in north-central mexico because harvest peak is concentrated on those months. harvest delay is an option to alleviate this problem and it was the aim of the research conducted. four-year-old cactus pear trees cv. cristalina were used in this trial. the treatments were: 1) leaving the normal development of the first vegetative and reproductive flux, which was considered as control, and 2) inducing a second vegetative and reproductive flux. the second treatment set back the harvest by 45 days, increased weight and flesh firmness of fruit, but yield was reduced by 65% compared with control. after four weeks in storage, flesh firmness and dry mass concentration were higher in out of season fruits. it is possible to delay the harvest period of the cv. cristalina, however, additional research work is needed under different environments and other cactus pear cultivars with high commercial value.
Remover las yemas reproductivas afecta la época de cosecha del nopal tunero?
Jorge A. Zegbe,Jaime Mena Covarrubias
Revista fitotecnia mexicana , 2008,
Abstract: Producir fruta de nopal tunero (Opuntia spp) fuera de temporada es importante para alcanzar precios más altos. Este trabajo probó la hipótesis de que eliminar las yemas reproductivas podría retrasar o adelantar la maduración de la fruta de los cultivares Cristalina y Rojo Liso . Los tratamientos consistieron en eliminar las yemas reproductivas más desarrolladas, o bien las más jóvenes, más un testigo que consistió en permitir el desarrollo normal de las yemas reproductivas, excepto las yemas dobles que fueron eliminadas. La eliminación de las yemas reproductivas más desarrolladas o las más jóvenes ni atrasó ni adelantó la cosecha en ambos cultivares, por lo que esta estrategia no es útil para modificar el tiempo de la cosecha; pero la aplicación de estos tratamientos aumentó el tama o del fruto y redujo el rendimiento en ambos cultivares, aunque no significativamente en Cristalina . Así, con el raleo de yemas se logró producir fruto de mayor tama o que en las plantas testigo, lo cual es importante para un mercado selecto nacional y de exportación.
Sistemas de manejo para la producción sustentable de chile seco cv. `mirasol′
Alfonso Serna Pu00E9rez,Jorge A. Zegbe,Jaime Mena Covarrubias,Salvador Rubio Du00EDaz
Revista fitotecnia mexicana , 2008,
Abstract: La producción de chile (Capsicum annuum L.) para secado requiere de grandes cantidades de agua y de un uso itinerante e intensivo del suelo. En consecuencia, nuevas tierras son abiertas al cultivo para resolver problemas de baja productividad, contaminación del suelo y enfermedades de la planta. La sustentabilidad del cultivo debe orientarse hacia nuevos sistemas de manejo y estrategias alternativas en el manejo del riego. En este trabajo se probaron tres sistemas de manejo del cultivo y dos formas de aplicación del riego sobre el rendimiento, calidad, productividad del agua e incidencia de enfermedades de chile cv. Mirasol para secado. Los sistemas resultaron de la combinación de prácticas de incorporación de abono verde al suelo y la aplicación de insumos inorgánicos y orgánicos para la fertilización y control de organismos da inos. Los sistemas evaluados fueron: convencional, intermedio y orgánico. Las formas de riego fueron: riego completo y riego parcial de la raíz (RPR). El menor rendimiento se obtuvo en el sistema orgánico, pero éste produjo mayor proporción de frutos de primera y segunda y menos frutos manchados. La menor incidencia de la enfermedad llamada secadera (Phytophthora capsici) se presentó en el sistema intermedio, mientras que la más baja productividad del agua se observó en el sistema orgánico. El RPR produjo menos frutos manchados, incrementó la productividad del agua y disminuyó la incidencia del amarillamiento del chile; pero redujo el rendimiento. Además, el RPR redujo el volumen de agua de riego aplicado en 25 %.
Aproximaciones al concepto de sociedad civil en Hegel
Misael Flores,Jaime Espejel Mena
Espacios Públicos , 2006,
Abstract: En la filosofía política hegeliana la idea de sociedad civil adquiere un matiz distinto a como era propuesto por la doctrina jusnaturalista y la ilustración escocesa, sobre todo por Adam Ferguson. Dado el sistema filosófico de Hegel, el lugar de la sociedad civil se encuentra en el espacio de la eticidad, como el espacio de plena contingencia en la cual las conciencias están solas. La eticidad representa el momento institucional en el cual el Estado y las familias tienen cupo, pero el momento preciso de la sociedad civil se encuentra en la disociación institucional. Así que la sociedad civil es un momento en el que deviene la libertad del individuo, que busca superar la contingencia y el conflicto mediante la intersubjetividad: este lugar es el mercado. La sociedad civil es un momento ético en el que la libertad es practicada en el mercado como mecanismo para conciliar las conciencias y superar el conflicto y la contingencia.
Púrpura trombocitopénica autoinmune. Informe de 108 casos
Covarrubias Espinoza, Roberto;Sotelo Cruz, Norberto;Hurtado Valenzuela, Jaime Gabriel;
Boletín médico del Hospital Infantil de México , 2004,
Abstract: introduction. autoimmmune thrombocytopenic purpura (atp) is a hemorrhagic disease with a more frequent presentation in infancy. could appear with an all level of bleeding and sometimes involves the central nervous system (cns). it is divided in 2 groups: the acute thrombocytopenic purpura (a-atp) and the chronic form (c-atp). objectives. to identify the presentation, evaluation and therapeutic modalities applied to patients with a-atp. material and methods. we realized a retrospective study in the internal medicine. unit at the children's hospital in the state of sonora, detecting 108 patients with the diagnosis of atp in the last 10 years. the variables studied were: age gender, clinical features, complications, treatment and evolution. results. we observed that the disease was more frequent in children under 6 years of age; there were no significant differences regarding gender, and the most common symptoms were bleeding of mucocutaneous tissues: 89% of the patients received treatment with prednisone; gammaglobulin and danazol in 4.5% and splenectomy 11 cases (14.5%); no evidence of mortality due to cns hemorrhage; 85% presented remission and 15% went to chronicity. urgent splenectomy was not required in our group, but these who underwent this type of surgery were cured in 91%. conclusions. being atp an autoimmune disease the majority of patients may go under remission even without treatment; however, we have observed better results in the use of steroids, shortening their hospital stay; in this series we did not had any of the most severe complications of atp.
Análisis cualitativo de un modelo de pesquerías de acceso abierto
GONZALEZ O,EDUARDO; MENA L,JAIME;
Investigaciones marinas , 1994, DOI: 10.4067/S0717-71781994002200001
Abstract: a qualitative analysis of bioeconomic model of a single species fishery is developed using a harvest function that is more realistic than the schaefer hypothesis. the existence of a bifurcation of steady states and its stability are discussed. several comments are made regarding the behavior of this model of open-access fishery under changes of some parameters. a variety of complexities, both biological and economic, are also discussed including the bioeconomic equilibriums and the level of extintion, collapse of the population as well as the self-control of the fishery. diverse curves of the phase portrait are shown.
Aplicaciones del refuerzo positivo a la reducción de accidentes en el trabajo
Luis López Mena,Jaime Veloz Antidrian
Revista Latinoamericana de Psicología , 1990,
Abstract: A system for the reductíon of accidents in the enterprise was devised, founded in operant conditioning (token economy) principies. 1t is calIed "Green Card" and it is centered on positive reinforeement. It was used with .three Chilean enterprises, with a total of 914 workers. Results indicated that accídentabilítv index reductíon was 62.8%. A follow-up of three years showed that the obtained reductíon was maintained. The importance of this system for the prevention of industrial accidents. is indicated
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