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

Objective: to analyze the determinants of soybean production and imports in Mexico, during the period 1990-2020. Design/methodology/approach: Two econometric models using lineal models were estimated to evaluate the relationships between the variable’s soybean production and harvested area and soybean production and imports. Results: It was found that soybean production in Mexico is explained by the increase in harvested area, because of the expansion of the internal market and the reconversion of soybean crop areas. In the second model, it was verified that imports are explained by the limited national production. Proposals for actions are presented to increase the national production of soybeans. Limitations on study/implications: The models require considering new variables to enrich the determinants and improve the proposal of public policy actions. Findings/conclusions: The low rate of national coverage and the high dependence on imports make it necessary to implement actions to increase the national productive capacity. A group of specific actions are proposed.

Objective: To learn about the state of the natural resources and the productive systems in the Santiaguillo basin from the viewpoint of the inhabitants. Methodology: It was approached from a qualitative approach, by means of a focus group. Results: The problems perceived are related to: access to water both due to its low availability and due to the inequity in its distribution that generates low productivity and conflicts over the use of this resource; low prices for agricultural products, conflicts arising from the use of wildlife, and the degradation of rangelands as a result of overgrazing. Limitations of the study: The Mennonite group, which is an important actor within the basin, was not represented in the focus group. Conclusions: The participants in the group perceive the basin´s problem problem of the basin in an integrated manner , linking natural, economic, social and political resources components, which leads them to actions adapted to their context to solve these problem. Keywords: Socio-environmental conflicts, perception, focus group, ecosystem degradation, endorheic basin.

Objective: to establish that the price of the main products of the Mexican agricultural sector are cointegrated with the production of the main producing States of the five regions of the Mexican agricultural sector. Design/methodology/approach: thirty cointegration tests were carried out to determine if prices influence the production of the main producing States of the regions of the agricultural sector of Mexico of the main products of Mexico, which are grain corn, grain sorghum and bean. Results: in the northwest region, the price does not influence the production of the main producing States of grain corn, grain sorghum and beans; In the northeast, central-western and central regions, the price influences the production of the main producing States of grain maize, grain sorghum and beans; and, in the south-southeast region, in most of the States, the price does not affect the production of the main producing States of grain corn, grain sorghum and beans. Limitations on study/implications: Not all States and their main products were analyzed because it was not the objective of the investigation. Findings/conclusions: the price influences the production, but it does not influence in the same way the production of the five regions of Mexico and neither of the main producing States of grain corn, grain sorghum and beans.

Objective: Evaluate the nutrient concentration at the foliar level of chrysanthemums grown in tezontle sand using three concentrations of the Steiner Universal Nutrient Solution. Design/Methodology/Approach: A completely randomized design was used, each treatment represented a concentration of the nutrient solution and each concentration had 11 repetitions, the study variables were: foliar concentration of nutrients: N, P, K, Ca, Mg and S, plant height (AP), stem diameter (DT), number of leaves (NH), flower diameter (DF), fresh weight (PF) and dry weight (PS). Results: The results showed this order of extraction K>N>Ca>P>Mg>S, for all concentrations, the foliar N content was low in the three treatments (<3.35%), the P was found in high concentrations. (>0.63%), K was higher in the 100% concentration treatment, Mg (>0.44%) was in sufficient levels, in Ca the 100% concentration had greater absorption and finally the S content was only the adequate in the concentration of 100 %, in the morphological variables there were no significant differences. Limitations of the study/Implications: High temperatures helped the proliferation of pests; therefore, it would be good to have a better control of temperatures inside the greenhouse. Findings/Conclusions: Therefore, using different concentrations of the nutrient solution in chrysanthemums grown in tezontle sand affects the nutrient content at the foliar level but not necessarily its morphology.

Objective: The aim of this work  was to evaluate the diversity and abundance of bark beetles and ambrosial beetles and their relationship with temperature and relative humidity. Design/methodology/approach: The study was carried out in a pine-oak forest of the northeastern Sierra of the state of Puebla, where a monitoring system was established using Lindgren traps baited with frontalin, brevicomine, alpha-pinene and beta-pinene. Results: The presence of 23 species of bark beetles and ambrosial beetles was recorded. Gnathotrichus sulcatus (LeConte) and Pseudips mexicanus (Hopkins) were the most abundant species and their presence was significantly associated with places having  high relative humidity. Limitations on study/implications: The results obtained are limited to the studied ecosystem.  Findings/conclusions: It was concluded that the abundance of the species observed was closely related with climatic factors.

Objective: to make a reproductive characterization of the hair sheep breeds in the American tropics. Design/methodology/approach: reproductive variables information was collected from scientific search engines, such as Web of Science, Redalyc, Dialnet, PubMed, SciELO and Latindex. Results: the age of puberty in ewe lambs is highly variable. Similar results were found in adult ewes regarding estrus duration and incidence, estrous cycle length, seasonal anestrus, ovulation rate, fertility, gestation, and prolificacy. Limitations on study/implications: information on reproductive variables of hair sheep breeds is poorly known or non-existent. Findings/conclusions: puberty onset in ewe lambs ranges from 175 to 335 d of age when animals weight 15 to 43 kg. The length of the estrous cycle of hair sheep in Mexico is 17 d during the autumn-winter and 21 d in spring-summer. In Brazil, it lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The estrous occurrence was 97.1% in autumn-winter and 76.5 % in spring-summer. The estrous duration ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. Fertility is 80 to 100 % in temperate and 37 % in warm months. Gestation length ranges from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval range from 244 to 294 d.

Objetive: in the production of Dahlia spp., only chemical fertilization has been used, and an option that has not yet been explored is the implementation of a microbial inoculant. Therefore, the objective of this study was to evaluate the effect of the mycorrhizal fungus Funneliformis mosseae on the growth and development of the dahlia (Dahlia variabilis var. Variegated dwarf). Design/methodology/approach: the seeds were sown in polyethylene bags containing a mixture of black soil, peat moss, and agrolite. A completely randomized design was used, and the treatment structure was 2x3 factorial. The study factors were F. mosseae, chemical fertilization, and substrate sterilization. Results: an analysis of variance was performed, and the mean values of the treatments were compared with Tukey’s test (α = 0.05). Conclusions: with the inoculation of F. mosseae, a significant increase was obtained in the study variables: plant height, stem diameter, number of buds and flowers per plant; leaf + stem, flower, root, and total biomass, compared to non-inoculated plants. A colonization of 89 % in the roots was recorded. A limitation of the study is that the effect of the inoculum on plant growth can vary according to the mycorrhiza species used. In conclusion, inoculation with Funneliformis mosseae increased growth and biomass accumulation in Dahlia plants.

The objective of this work was to apply statistical quality control to evaluate the efficiency of biofertilizers for the sustainable development of guava (Psidium guajava) crops in Chiapas, Mexico. Physicochemical parameters were analyzed to determine soil fertility in guava crops. The structure and diversity of the bacterial community was studied by structural metagenomics. A quality control statistical analysis was applied to determine the effect of biofertilization on the growth and production of the guava plant crop. Rhizobial biofertilization significantly improved the growth and production of the guava crop. S. mexicanum ITTG-R7 stood out as a PGPB species that can contribute to the growth of guava plants and also improve the quality and functionality of the soil. Phytotechnical management, agricultural inputs, soil nature, labor, raw material were the main causes that are related to low yield in guava cultivation. Experimental statistical analyzes and quality control are effective tools to determine the efficiency of biofertilizers in fruit crops.

Objective: To use extracts of pomegranate as a reducing agent to the simple and eco-friendly biosynthesis of silver nanoparticles and their antimicrobial evaluation against different bacteria. Methods: The peel of the ripe fruits and leaves of pomegranate were used to prepare aqueous and methanolic extracts to synthesize silver nanoparticles (AgNP) these nanoparticles were evaluated by techniques used for the characterization of nanoparticles that allow defining their size, shape and quality of dispersion in aqueous media. They were characterized by UV-Vis spectroscopy and dynamic light scattering (DLS). The antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis y Staphylococcus aureus was determined. Results: UV-Vis spectra with absorption peaks at 425 nm were observed for the nanoparticles synthesized with aqueous extract as well as for the nanoparticles synthesized with the methanolic extract. Regarding the size distribution and dispersion in solution, the zeta potential shows that the surface charge in all cases is negative with an average value from -28.0 mV to -52.0 mV. About the size, smaller nanoparticles were obtained from the aqueous extracts of the peel and leaf with values between 1.42 - 2.96 nm and10 - 19.04 nm for nanoparticles from the methanolic extracts. Inhibition of microorganisms by nanoparticles showed better inhibition against Escherichia coli with a MIC of 0.83 µg/mL up to 6.68 µg/mL. Conclusions: This study suggest that pomegranate extracts synthesize small-sized, well-dispersed nanoparticles with almost spherical morphology, with good antimicrobial activity against gram-negative bacteria such as Escherichia coli.

This article focuses on the social imaginary about women in the discourse of El Diario Austral de Temuco, a publication from Chile’s Araucanía region, during the enactment of women's suffrage in the country (1935-1952). Following Potter’s model of discourse analysis, the article examines the socio-imaginary constructions articulated in the factual accounts that circulated in the public arena of the local press. We find that this social imaginary was constructed along two central discursive axes: the domesticity of political participation, and the legitimacy of women's suffrage as grounded on their political contributions through the essential nature of their femininity.