Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

En un artículo recientemente publicado, Mahood (1977) desarrolla un estudio vulcanológico, petrográfico y geoquímico muy completo sobre las riolitas peralcalinas de la Sierra La Primavera, ubicada al suroeste de Guadalajara… In order to continue, download the full paper in PDF.

Nuestra lexicología española de especies mineralógica tiene muchas ventajas en comparación con la propia de otros idiomas extranjeros, ya por la textura del lenguaje, ya por que la derivación de sus palabras sigue más de cerca la forma de las voces griegas y latinas… In order to continue, download the full paper in PDF.

  Mexico is the center of origin and domestication of maize (Zea mays L.), in some regions there are still creole populations with the potential to generate improved varieties. The objective of this study was to evaluate the agronomic and physiological behavior of twelve maize populations native to southeastern Mexico. The experiment was carried out in Tizimín, Yucatán in 2017. 32 parameters corresponding to vegetative, phenological, agronomic and physiological variables were evaluated. The results showed a difference of 75 cm between the lower plants (Xn-69) and those of higher bearing (CNB), the plants of the population DZ-252 presented greater foliage (19.1 leaves) and greater stem diameter (26 mm), the earliest populations were CM and CCB (65.5 and 65.8 days, respectively). 58% of the populations evaluated exceeded the average yield of the region (4.5 t ha-1). The highest yield was obtained by the CM, Cro, H1 and SP2015 populations (117.7, 105.8, 111.5 and 109.5 g plant-1, respectively). The populations CM, DZ2015, Cja and Cro had a higher photosynthetic rate; however, the highest water use efficiency was presented by the DZ-252 and XnQroo populations (8.9 μmol CO2/mmol H2O). The CM population stood out for its performance and precocity, the DZ-252 could be used as fodder for the amount of biomass it generated and the XnQroo should be studied under conditions of water restriction for its efficiency of water use, these three populations should be included in breeding programs.

In the present essay, an alternative for the production of biofertilizers is proposed based on the use of macroalgal blooms that are occurring in the coastal lagoons of Sinaloa. Coastal communities can obtain an economic benefit by properly harvesting part of the biomass resulting from such blooms. The extracted macroalgal biomass could be used to produce biofertilizers, with the following benefits: a) mitigate the ecological damage caused by macroalgal blooms to eutrophicized coastal ecosystems; b) the use of organic fertilizers in agricultural fields allows N and P to be recycled, thus avoiding the application of more synthetic fertilizers, which are primarily responsible for macroalgal blooms; c) in addition to containing biofertilizers based on macroalgae, N and P contain a set of micronutrients and substances with the potential to benefit crops and improve soils; d) it contributes to carbon sequestration and the reduction of greenhouse gases in the atmosphere; and e) economic benefits in the use of a raw material, nowadays, of low value or without commercial value. Such biofertilizers would be used to produce fruits and vegetables of the so-called organic, which have a high surplus value and their demand is increasing in Mexico and in the world. This is an alternative focused on the production of biofertilizers for use in organic agriculture and production of fruits of high economic value, which can be accredited as organic and at the same time, contribute to the improvement of soils and the state of health of coastal ecosystems

The fusariosis of the spike by Fusarium graminearum is a disease that affects the yield and sanitary quality of the barley grain. Among the control measures is the use of resistant varieties, so this work had as objectives to evaluate the resistance to fusariosis and the accumulation of deoxynivalenol (DON) in 131 advanced malting barley lines selected for their tolerance to yellow rust, rust of the leaf, reticulated spot, leaf blight and scald of the leaf, of the barley program of the INIFAP-CEVAMEX. For three years, the advanced lines 30, 47, 65 and 123, as well as lines 73, 91 and 96, of six and two rows of grain, respectively, registered very low symptoms of fusariosis in response to inoculation with F. graminearum. Although the severity of the disease was not related (r= 0.5682) to the accumulation of DON, these lines registered very low or no toxin production. The information generated in this study is relevant because it indicates that these lines are resistant to the disease and have the potential to be used as sources of resistance in a crossbreeding program in malting barley that includes spike fusariosis in all diseases.

The objective of the study was to estimate the willingness to pay (DAP) for organic products in Texcoco, State of Mexico, as well as determine the socioeconomic variables that most influence the DAP of people for organic products, under the hypothesis that there is a DAP positive among the participants. 130 surveys were applied in the municipality of Texcoco, State of Mexico in the period from January 1 to March 31, 2017. The DAP was estimated for organic products in the area, using the contingent valuation method and a Logit Binomial model, using the Nlogit software, the variables that explain the DAP are price, gender, age, marital status, level of education and income, concluding that the inhabitants of the study area are willing to pay an extra amount in the price of basic products (lettuce, tomato and rice) if they are produced organically. In the case of lettuce, a DAP of 7.50 $ piece was determined, for tomato 11.00 $ kg and for rice 32.5 $ kg, which represents 53%, 41.5% and 2228% respectively.

The use of beneficial microorganisms is a viable alternative to incorporate into legumes to improve fertility and increase nitrogen fixation in the soil. In this work the application of arbuscular mycorrhizal fungi (AMF), Rhizobium etli (Re) and a reduced dose of inorganic fertilizer in the production and quality of bean (Phaseolus vulgaris L.) cv. ‘Negro Michigan’ under field conditions. The work was carried out in the ‘La Bandera’ Experimental Field located in the municipality of Actopan, Veracruz, during the spring summer 2016 cycle. An experimental randomized block design with eight treatments was used [T1: (control, T) , T2: (fertilized, F), T3: (inoculated with AMF), T4: (inoculated with Re), T5: (inoculated with AMF+Re), T6: (inoculated with AMF+50%F), T7: (inoculated with Re+50%F) and T8: (inoculated with AMF+Re+50%F)], each treatment with three blocks and 500 plants in each. Plant height, stem diameter, number of leaves, flowers, pods and nodules, weight of grains, seed quality variables, total protein content and percentage of root colonization were evaluated. An analysis of variance and Fisher’s LSD test with a significance level of 5% were used. The results showed significant differences between treatments (p≤ 0.05) for the registered variables, with AMF+Re+50%F being the treatment where not only was the quality of the bean grain improved, but the use and fertilization costs would be reduced in favor of the producers’ economy.

El objetivo de la investigación fue determinar la magnitud del efecto de las principales variables económicas y tecnológicas que influyen en la oferta y demanda de carne de pollo en ocho regiones de México, durante el periodo de 1996 a 2016. Se formuló un modelo econométrico de regresión lineal múltiple para cada región donde se incluyeron las variables económicas y tecnológicas principales que determinan la oferta y demanda. La oferta carne de pollo en canal reacciona directa y elásticamente a cambios en la tecnología, directa e inelásticamente por el precio de la carne de pollo e inversa e inelásticamente por el precio de la carne de cerdo y precio del alimento, en la mayoría de las regiones, cuyos valores promedio regionales fueron 1.7395, 0.9912, -.03686 y -0.1423. La demanda se comportó de manera elástica, respecto al tamaño de la población e inelástica en relación al precio corriente de la carne de pollo, ingreso per cápita y precio corriente de la carne de bovino en todas las regiones, reportando valores promedio de 2.0853, -0.1698, 0.2560 y 0.0272; el crecimiento de la pomdablación fue la variable que mayor incidencia reportó sobre el consumo de carne de pollo en las distintas regiones de México. Todos los modelos tuvieron significancia global; sin embargo no todas las variables predictoras mostraron significancia individual.  

The study was to determine the presence of Classical Swine Fever virus (CSFv), in the meat of vaccinated pigs with the PAV-250 strain and then challenged using the same strain. Five treatment groups were established (each with four pigs). Group A: Pigs thatwere fed with processed hams from negative animals; Group B: Pigs that were fed with processed hams from commercial pigs inoculated with the ALD (reference strain) (titre of 104.0/ml); Group C: Pigs fed with processed hams from pigs infected with the virulent ALD strain (titre of 102.5/ml); Group D: Pigs fed with processed hams from pigs vaccinated with the PAV-250 strain and challenged with the ALD strain (titre of 101.1/ml); and Group E: Pigs fed with processed hams from pigs vaccinated with two doses of the PAV-250 strain and challenged with the ALD strain (negative). Blood samples were taken at d 1, 5, 10, 15 and 20 for biometric analysis. Groups B, C and D manifested clinical signs of CSFv: 40 °C temperature, anorexia, paralysis, vomiting, diarrhea, tremor, hirsute hair and cyanosis. Pigs were slaughtered and necropsies performed to identify lesions in tissues. Results of direct immunofluorescence testing of tissues were positive and the virus was recovered. Under these study conditions, it was found that CSFv resisted the cooking method at 68 °C for 40 min in hams from unvaccinated pigs, and that the virus was able to transmit the disease to healthy unvaccinated pigs, whereas the hams from the vaccinated animals did not transmit the virus.