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Search Results: 1 - 10 of 171213 matches for " E.;MORA-AGUILERA "
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Acta zoológica mexicana , 2010,
Abstract: El nopal Opuntia ficus-indica se cultiva con diversos propósitos en el mundo, mientras que en México, principal productor y consumidor mundial, particularmente se consume como verdura (nopalitos). La producción de nopalitos se ubica, principalmente, en los alrededores de la Ciudad de México donde las cochinillas silvestres Dactylopius spp. son de los insectos más nocivos para el cultivo. El control químico es el método de más uso por los productores, aunque el control biológico podría ser útil para un manejo integrado de plagas. No obstante, los estudios taxonómicos sobre las especies de cochinilla y sus enemigos naturales en México no son abundantes. En esta investigación se planteó conocer las especies presentes de Dactylopius y sus enemigos naturales en Tlalnepantla, Morelos, una de las áreas de mayor producción de nopalitos en México. Se seleccionaron 30 sitios distribuidos en esta región y se establecieron cinco sitios para monitoreo de enemigos naturales cada dos semanas durante un a o. La única especie de cochinilla silvestre del nopal que se encontró correspondió a Dactylopius opuntiae (Cockerell), los enemigos naturales en orden de abundancia fueron Leucopis bellula, Sympherobius barberi, Laetilia coccidivora, Hyperaspis trifurcata, Salpingogaster cochenillivorus, Sympherobius angustus y Chilocorus cacti. Se proporcionan descripciones de biología de los enemigos naturales en campo y laboratorio. Diversos factores relacionados con el manejo del cultivo tuvieron un efecto sobre las poblaciones de D. opuntiae y sus enemigos naturales.
Enemigos naturales de Dactylopius opuntiae (Cockerell) en Opuntia ficus-indica (L.) Miller en el centro de México
Acta zoológica mexicana , 2010,
Abstract: prickly pear, opuntia ficus-indica (l.) miller, is cultivated for many purposes around the world. in mexico, people consume young pads as vegetables and call them "nopalitos". the production of nopalitos occurs mainly around mexico city where cochineal insects (dactylopius spp.) are one of the most important pests. farmers partly control dactylopius using insecticides, but biological control could offer a tool for the integrated pest management. in this paper the cochineal insects and their natural enemies were studied in tlalnepantla, morelos, one of the most important regions for nopalitos production in mexico. in order to determine dactylopius species, 30 samples sites were selected in this region. additionally natural enemies were collected every other week during one year period in five different zones. dactylopius opuntiae (cockerell) was the only cochineal species found in tlalnepantla. the natural enemies, in order of abundance, were leucopis bellula, sympherobius barberi, laetilia coccidivora, hyperaspis trifurcata, salpingogaster cochenillivorus, sympherobius angustus, and chilocorus cacti. we also included some lab and field biology descriptions of these predators. diverse factors of crop management appeared to affect d. opuntiae population and their natural enemies.
Evaluación de insecticidas sintéticos sobre adultos de Metamasius spinolae (Coleoptera: Curculionidae) procedentes de Tlalnepantla, Morelos
Cerón-González, Claudia;Rodríguez-Leyva, Esteban;Lomeli-Flores, J. Refugio;Hernández-Olmos, Claudia E.;Pe?a-Martínez, Rebeca;Mora-Aguilera, Gustavo;
Revista mexicana de ciencias agrícolas , 2012,
Abstract: the cactus weevil, metamasius spinolae (gyllenhal), is one of the most important pests in prickly pear (opuntia ficus-indica (l.) miller) in mexico and especially in tlalnepantla, morelos, the second most important region in the production of this crop, with about 2 500 ha. both adults and larvae cause damage to this crop; larvae make galleries in mature pads and adults damage young pads of the cactus. although there are no authorized pesticides for its control in mexico, this fact does not stop farmers from using synthetic insecticides without knowing their effectiveness. for this reason, this study evaluated the effectiveness of eight pesticides in two chemical groups, organophosphates and pyrethroids, on adults of this insect. the laboratory and field tests conducted in 2007 showed that malathion caused a mortality similar to other more toxic products in the same group (methyl parathion and methidathion). on the other hand, only a pyrethroid insecticide (permethrin) provided a mortality rate close to 86%, in comparison to the remaining three (cypermethrin, deltamethrin and fenvalerate) which caused a mortality of under 20% mortality. there was a differential response of the sex of the insect to insecticides, in which females were less susceptible than males to some products, such as diazinon, permethrin and cypermethrin. this is the first formal report of the evaluation of synthetic insecticides in this insect and we discuss some issues related to management.
Evaluación de barreras vegetales en el manejo integrado de la mancha anular del papayo (PRSV-P) en Michoacán, México
Rivas-Valencia, Patricia;Mora-Aguilera, Gustavo;Téliz-Ortiz, Daniel;Mora-Aguilera, Antonio;
Summa Phytopathologica , 2008, DOI: 10.1590/S0100-54052008000400001
Abstract: the effect of plant barriers as a component of an integrated management program (im) was validated and adapted in 1999, in michoacan, mexico, to control papaya ringspot, caused by papaya ringspot potyvirus type-p (prsv-p). a split-plot design was established with two experimental factors: plant barriers and components of im: im without oil sprinkling (im-o), im without plant rouging (im-r), and complete im. plant barriers (hibiscus sabdariffa), sowed 20 days before papaya transplanting, and plant rouging delayed the epidemics onset in 19 days thus im resulted in the highest yield (14.2%) than the rest of the treatments, but it was less effective than im-o in vigor (4% in stem diameter). oil sprinkling was phytotoxic and caused a 5.3% vigor reduction. the oil effect on the disease progress was not clear, since the epidemic intensity (epidemic onset x0 = 47 days after transplanting, final incidence yf = 81% and area under disease progress curve abcpe = 3220 %days) was similar to the control treatment. plant barriers alone may not be sufficient to reduce disease incidence and spreading. the more abundant winged aphids known as prsv-p vectors were aphis gossypii, a. nerii, a. spiraecola and macrosiphum euphorbia, which represented approximately 13% of the total captured aphids.
Sensibilidad de inmunoimpresión-ELISA y DAS-ELISA en el diagnóstico y muestreo del virus de la tristeza de los cítricos en huertos comerciales de Tamaulipas, México
Ruiz-García, N.;Mora-Aguilera, G.;Rivas-Valencia, P.;Góngora-Canul, C.;Loeza-Kuk, E.;Ochoa Martínez, D.;Ramírez-Valverde, G.;Gutiérrez-Espinosa, M. A.;álvarez-Ramos, R.;
Revista Chapingo. Serie horticultura , 2009,
Abstract: the citrus tristeza virus (ctv) causes a disease of regulatory interest for the mexican citriculture. timely and reliable sampling and diagnosis is essential for management strategies to check the spread of the brown citrus aphid, its main vector, in national territory. because it is cheap and operationally feasible, direct tissue blot immunoassay-elisa was compared with to das-elisa, the official method for diagnosis, in order to establish an effective and efficient method for ctv detection. for the comparison, a total of 7421 trees of 11 commercial orchards of tamaulipas, grouped by budding and infection age were tested. the direct tissue blot immunoassay technique was more sensitive and more capable of positive prognosis than das-elisa in the diagnosis of ctv (p≤0.028) in trees with recent and unknown infection. buds diagnosed positive were heterogeneously distributed throughout the canopy, described by the beta binomial function (p≤0.16-0.23). based on this function and the reproducibility (93.2%) of the results of double petiole printing suggested an optimal sample size of 10 petioles in single print. this method was 54.9% more economical than das-elisa and the diagnoses require only 17% of the time invested for das-elisa. however, due to the requirements of the current mexican official norm (nom-031-fito-2000), this method is recommended as a fast technique to discriminate positive trees in field sampling to be later verified with the official method of diagnosis.
Elabora??o e valida??o de escala diagramática para avalia??o da severidade da ferrugem branca do crisantemo
Barbosa, Maria Angélica G.;Michereff, Sami J.;Mora-Aguilera, Gustavo;
Summa Phytopathologica , 2006, DOI: 10.1590/S0100-54052006000100008
Abstract: white rust, caused by puccinia horiana, is considered the major disease of chrysanthemum in brazil, which results in severe losses for the growers. despite of its economic importance, very few epidemiological studies have been carried out in brazil. in order to conduct these studies it is necessary to develop standard methods to quantify disease severity under field conditions. therefore, a diagrammatic key, including the levels 1, 3, 6, 10, 18, and 30% of diseased leaf area, was elaborated. the severity of the white rust was estimates using the key or not in order to test its accuracy, precision and reproducibility. the diagrammatic key was validated by 10 raters using 50 leaves with different levels of severity, which were previously measured by the autocad? software. two evaluations were performed with the key at 7-day intervals when different sequences of the same leaves were visually estimated by the same raters. the accuracy and precision of each rater were determined by using simple linear regression between actual and estimated severity. when the key was not used, all raters overestimated disease severity indicating the presence of constant positive errors for all levels of disease severity. the evaluations using the diagrammatic key were more accurate for the great majority of the raters and more precise for all the raters. in addition, the key also showed good repeatability and high level of reproducibility among the evaluations from the different raters. the diagrammatic key is suitable for the evaluation of severity of white rust of chrysanthemum.
Análisis espacio-temporal de aislamientos del Citrus tristeza virus de Yucatán y Tamaulipas Spatio-temporal analysis of Citrus tristeza virus isolates from Yucatán and Tamaulipas
Patricia Rivas-Valencia,Emiliano Loeza-Kuk,Gustavo Mora-Aguilera,Noé Ruiz-García
Revista mexicana de ciencias agrícolas , 2010,
Abstract: Se estudiaron huertas comerciales de cítricos (Citrus sinensis L.), ubicadas en las principales regiones productoras de Yucatán de 2003 a 2006 y en Tamaulipas en 2004. En Yucatán se realizó un estudio espacio-temporal de la dispersión de la tristeza de los cítricos, ocasionada por el Citrus tristeza virus, en presencia de Toxoptera citricida Kirkaldy. La incidencia inicial (X0) fue de 4.41% y la final (Xf) de 39.33%. Los índices de agregación de Morisita y Lloyd dependientes del tama o óptimo de cuadrante, mostraron un patrón agregado con valores entre 1.41 y 2.39. Además, se caracterizaron molecularmente aislamientos del Citrus tristeza virus, para examinar la diversidad del virus presente. Se analizaron aislamientos del virus con single-strand conformation polymorphism, observándose hasta dos haplotipos por aislamiento y tres tipos de patrones en Yucatán. En Tamaulipas, con la caracterización molecular, se identificaron tres haplotipos por aislamiento y siete patrones. El coeficiente de similaridad calculado para estas dos poblaciones de aislamientos fue de 0.7, asumiéndose un origen común de ambas poblaciones. El análisis de varianza molecular, indicó mayor variabilidad dentro de las poblaciones (69%) y entre ellas (31%), comprobando que ambas regiones citrícolas, comparten variantes caracterizadas como de tipo moderado, mismo que puede justificar la ausencia de sintomatología atribuible a tristeza. Los análisis realizados para identificar el patrón de dispersión de los aislamientos en campo no evidenciaron la dispersión entre árboles e hileras. Citric (Citrus sinensis L.) commercial vegetable gardens were studied, located in the main producing regions of Yucatán from 2003 to 2006 and in Tamaulipas in 2004. In Yucatán it was carried out a space-time study of dispersion of citric tristeza, caused by Citrus tristeza virus, in presence of Toxoptera citricida Kirkaldy. The initial incidence (X0) was of 4.41% and the final (Xf) was of 39.33%. The aggregation indexes of Morisita and Lloyd dependent of the optimum size of quadrant showed an added pattern with values between 1.41 and 2.39. Also, isolations of Citrus tristeza virus were molecularly characterized to examine the diversity of current virus. Virus isolations were analyzed with single-strand conformation polymorphism, being observed up to two haplotypes by isolation and three types of patterns in Yucatán. In Tamaulipas, with the molecular characterization, three haplotypes were identified by isolation and seven patterns. The similarity coefficient calculated for these two populations of isolations
Ocurrencia de hongos y etiología de la secadera de la fresa con diferentes sistemas de manejo agronómico
Ceja-Torres, Luis F.;Mora-Aguilera, Gustavo;Téliz, Daniel;Mora-Aguilera, Antonio;Sánchez-García, Prometeo;Mu?oz-Ruíz, Carlos;Tlapal-Bola?os, Bertha;De La Torre-Almaraz, Rodolfo;
Agrociencia , 2008,
Abstract: in méxico, strawberry dry wilt (fragaria x ananassa) has been associated with a fungus complex in which only the implication of fusarium oxysporum (fox) is evident. therefore, in the present study the association of fungi and pseudofungi with the disease was determined in different systems of agronomical management, and pathogenicity was verified. two samplings were made in the 2002/03 season and three in 2003/04 in 16 localities of the valley of zamora, michoacán, méxico, where 2640 sections of roots and 365 of necrotic crowns were sown, along with 400 sections of asymptomatic tissue in potato-dextrose-agar (pda) culture medium and a selective medium with antibiotics and pcnb (parph) fungicide. fox, f. solani (fso), cylindrocarpon sp. (cyl), pythium aphanidermatum (pyt), phytophthora sp. (phy), rhizoctonia fragariae (rhi), verticillium albo-atrum (ver) and colletotrichum sp. (col) were associated with the dry wilt. fox was the most frequent species (p=0.05) and the only one that showed an increase from flowering to fructification of 47 to 62% in root and 77 to 83% in crown. in plantations with plastic mulch and drip irrigation (a + g), fox decreased by 18% with respect to unmulched soil with gravity irrigation, whereas cyl increased by 15% in a + g (p=0.05). the clay and clay loam soil contrasted in the detection of fox (46.8 and 12.4%) and rhi (9.1 and 43.7%). symptoms of wilting with necrosis in root and crown and general death were reproduced with individual inoculations of fox (100%), pyt (100%), phy (100%), rhi (60%) and combinations of fox with rhi (100%), pyt (100%) and cyl (100%). this is the first report that implies phytophthora sp., p. aphanidermatum and r. fragariae as causal pathogens of dry wilt in méxico. the morphological identification of fox and rhi was confirmed by sequencing of the intergenic region of the rdna.
Etiología e histopatología de la muerte descendente de árboles de mamey (Pouteria sapota (Jacq.) H. E. Moore y Stearn) en el estado de Guerrero, México
Vásquez-López, Alfonso;Mora-Aguilera, José A.;Cárdenas-Soriano, Elizabeth;Téliz-Ortiz, Daniel;
Agrociencia , 2009,
Abstract: in alpoyeca, guerrero, méxico, dieback on mamey trees (pouteria sapota) is a disease of unknown etiology that reduces productivity and longevity of commercial orchards. in this study the etiology of the disease and anatomic damage it causes to branches were determined. from symptomatic branches, lasiodiplodia sp. was consistently isolated, and its pathogenicity was verified on mamey branches with epidermis and peridermis (with and without lesions). after 30 d, the fungus produced necrotic lesions on branches with peridermis inoculated through wounds, and in 24 months it induced dieback of vegetative shoots. the control branches remained asymptomatic. the anatomical damage on symptomatic branches included peridermis rupture, collapse and necrosis of cortical, phloem, and laticifetous cells, and external phloem fibers and vasculat cambium. in the phloem, crystals and granular precipitates formed; the radial and the axial parenchyma lignified, and sclereids formed. the xylem and medulla were not damaged. based on its motrphological and molecular characteristics, the fungus that induced dieback on mamey trees in alpoyeca, guerrero, was lasiodiplodia theobromae. the genetic sequence of the pathogen was deposited in the gene bank (ncbi) with access number eu564805.
Barreras de maíz en una estrategia de manejo integral para controlar epidemias del virus mancha anular del papayo (PRSV-P)
Hernández-Castro, Elías;Villanueva-Jiménez, J. Antonio;Mora-Aguilera, J. Antonio;Nava-Díaz, Cristian;
Agrociencia , 2010,
Abstract: te epidemics caused by papaya ring spot virus (prsv-p) (carica papaya l.) have been delayed by an integral management system (mip), although the individual efectiveness of some components has not been measured. te establishment of corn (zea mays l.) barriers was evaluated in the control of prsv-p in veracruz, mexico. te mip included the protection of the nursery with polypropylene mesh, 2743 plants ha-1, eradication of diseased plants, mineral fertilization and weed control. treatments were: integral management with corn barriers (mip), integral management without barriers (miz) and regional management (mr, 1600 plants ha-1, using insecticides, without barriers and elimination of diseased plants). te logistic model adequately explained the incidence in mip, miz and mr, and severity (r2=0.92 to 0.97) in miz; the exponential and gompertz models explained severity (r2= 0.92 and 0.98) in mip and mr. te highest epidemic rate was observed in mr (0.054), while mip reduced it by 42 % (0.031). barriers induced lower incidence and mean severity (yp -mip = 18.4 and 7.1 %; yp-miz = 23.4 and 11.7 %) and final (yf-mip = 81.0 and 35.7 %; yf-miz = 94.11 and 43.0 %). maximum severity at 238 d after transplant (dat) was observed in mr (69.0 %) and the lowest in mip (35.7 %). te absence of barriers increased the epidemics; in mr the maximum incidence (100 %) and severity (60 %) occurred 175 dat, while in mip, 238 dat (incidence 80 %, severity 35 %). barriers improved papaya health under mip by 14 % (yf-mip =81.0 % < yf-miz) and reduced severity by 47.7 % (mipaudpc=1621.1 < mizaudpc=2734.7). te mip, with and without barriers, increased yield from 76.3 to 94.4 % with respect to mr.
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