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

In the international arena, the production of Mexican avocado stood out in the first place, with 1,316,000 tons and 722,000 tons of avocado were destined for export in 2019, contributing more than 45% of the world export market. These imports represented a very significant percentage of avocado imports in countries such as the United States of America, Canada, Japan, Europe and Central America. Currently 100% of national requirements are satisfied with internal production, likewise, world imports have increased 171.97% in the last decade. The main objective of the work was to analyze the competitiveness of the avocado produced in Mexico during the study period from 1995 to 2019 in the world market, derived from the production surplus. Within the specific objectives, trade competitiveness indicators were calculated at the level of world importing markets, the Revealed Comparative Advantage Index (IVCR) and the Normalized Revealed Comparative Advantage Index (IVCRN) were calculated, data from the avocado exports as well as total agricultural exports made by Mexico to the world, and specifically to the United States, Canada and Japan. The importance of making an analysis of the main avocado production variables was to locate the situation of products from Mexico with respect to the world situation. The results obtained suggest that avocado production in Mexico is highly competitive at the international level.

ABSTRACT Objective: to evaluate the physiological development of Anthurium andreanum L. var. Tropical red color in three in vitro culture systems: semi-solid, partial immersion and RITA® bioreactor Design / methodology / approach: A completely randomized design was used with three treatments: semi-solid medium, partial immersion and RITA® bioreactor, with four repetitions each. Vitroplants of anthurium were selected with a size of 0.5 cm from the stem to the highest leaf, with three leaves each specimen. After 60 days of sowing, morphometric analyzes, chlorophyll content and hormone content were carried out. An analysis of variance and comparison tests of means were performed on the data obtained by Kruskal-Wallis and Tukey, respectively, using the statistical software R-STUDIO. Results: The highest shoot rate and root length was obtained in partial immersion; however, the number of leaves, shoots and root multiplication did not show differences with the RITA® bioreactors. The highest concentration of chlorophyll and indole acetic acid was observed when using RITA® bioreactors. Study limitations / implications: The results are favorable for the in vitro production of anthurium, however for commercial production the use of RITA® bioreactors is a high cost in the initial investment. Findings / conclusions: with the results obtained, it is considered that the RITA bioreactors obtained the best results for the production of anthurium, followed by the partial immersion system. Due to the liquid medium and better gas exchange, which favors the development of plants Keywords: Anthurium andreanum L.; chlorophyll; phytohormones; immersion systems

The objective of the study was to evaluate the variables of seed yield in situ in Bouteloua gracilis, Bouteloua hirsuta, Bouteloua curtipendula, Mulhenbergia rigida and Schizachyrium scoparium in La Siberia, Chapingo, Mexico. The study was carried out on wild plants in which it is applied, total stems per plant-1, number of branches plant-1, number of branches-1, number and quantity of seed-1, stem-1 and plant- 1 to later evaluate the filling percentage and viability. Data were analyzed with GLM of SAS in Completely Random Blocks design and Tukey's test (α = 0.05). There was no grass species that exceeded 25 flower stems per plant (P<0.001). B. gracilis showed a lower number of inflorescences per plant compared to B. hirsuta (P<0.001), however, with a higher number of branches (P <0.001). Seed production per plant (mg) was higher in M. rigida (P <0.001; 12902), followed by B. curtipendula (2246) and S. scoparium (1465). In physical quality of seed B. curtipendula presented a higher percentage of filling (P<0.001; 17%) and S. scoparium greater viability (P<0.001; 78%) and weight of 1000 seeds (P<0.001; 1.52 mg). In La Siberia, B. curtipendula and S. scoparium were identified as potential grasses to collect seed and then be used for reconversion or rehabilitation

Objetive: Describe the diversity of bat communities in two types of wetlands within the coastal plain of Tabasco's state to. Metodology: Samplings were carried out during three consecutive years in two different seasons of the year, dry and rainy; two types of vegetation, mangrove forest and popal-tular were considered. Mist-nets were used during three effective sampling days per station, spanning six-hour periods within 30-minute monitoring intervals. Results: A total of 510 individuals representing 22 bat species of six families were registered; the phyllostomid bats presented the highest richness and abundance. The bat species Artibeus jamaicensis, Noctilio leporinus, and Glossophaga soricine were the most representative. We found enhanced richness in the mangrove forest with 18 bat species, while popal-tular vegetation 12 species were found; the diversity of order 1 indicated that the mangrove forest richness is 0.78, which is highest than the popal-tular vegetation. Seven food guilds were identified, the frugivores were the most dominant; additionally, three bat species are under protection based on NOM-059-SEMARNAT-2010, representing 12% of the state's protected species. Implications: Evaluating the bats community in wetlands is important to know the richness and abundance of this group, to generate base information Conclusions: Mangrove forests were the type of vegetation with the largest richness and abundance of bats, which might be considered crucial for the conservation of this group of mammals, providing shelter and food. In general, wetlands are important habitats for this group.

Objective: To describe the dynamics of floral biology and fruit development until physiological maturity, by performing a qualitative and quantitative characterization in eight Mexican cacao clones (Theobroma cacao L.), called: Caehui, Chak, Canek, Chibolon, Supremo, Tabscoob, K'in and Olmeca. Design/methodology/approach: In the phenological study, five trees were taken into account and five flower buds per tree were randomly identified (n=225). Twenty-one (21) qualitative and quantitative morphological descriptors were evaluated in fruits and grains. Descriptive statistics were established and a principal component analysis was applied to the quantitative descriptors. Results: The Chak clone presented the highest value for length and diameter of flowers buds in reproductive phenology, with 7.4 mm and 4.2 mm; the K ́in clone stood out in fruits, with 252 mm length; and Supremo in fruit diameter, with 102 mm. Significant differences were found in the morphological variables evaluated, in addition to significant positive correlation (p<0.05 and p<0.001) between most of the variables. The first two main components described 62.5% of the total variation. Findings/conclusions: The differences in measurements (length and diameter) of the flower buds are attributable to the genetic constitution; however, knowing the opening times allows us to have an exact reference in production levels. The parameters that contributed most to the variability observed were weight and diameter of the fruit, length and width of the grain, thickness of the exocarp, and weight of grains per pod.

Micro-grafting and mini-grafting trials were carried out in order to obtain complete Pinus patula plants generated in vitro, derived from the fact that the formation of roots in micro-propagated shoots is very low or null. On the other hand, there is the possibility of generating clones with outstanding genetic characteristics. P. patula seeds were established in aseptic conditions and geminated in vitro in DCR medium; the aerial part was dissected from the base and roots were kept in DCR medium added with 0.5 mg l-1 of NAA to maintain them and served as mini rootstock, the shoots were transferred to DCR medium added with 2.0 mg l-1 of BA to form seedlings with an average of 3.9 shoots per explant at 30 days. On the other hand, 2-month-old nursery seedlings were used as rootstock for the mini-grafts. For the micro-graft tests, the shoots obtained were taken and the apical meristems with approximately 5 mm were isolated to conduct micro-grafting at the base with roots, and in the case of mini-grafts the shoots generated were allowed to grow to a length of 3 cm on average and grafted onto nursery seedlings. In both cases, the achievement of the grafted materials and the length were evaluated to measure the growth of the materials that had positive success. The response of micro-grafts was very low, 10% success, in addition to the manipulation of the meristems being very complex, which generated oxidation in the tissues. On the contrary, the mini-grafts showed 93.3 of grafting success and average growth of 26.05 cm, two months after the grafting process

Objective: analyze the competitiveness of the international marketing of the main flowers grown in Mexico with respect to the United States of America. Design/methodology/approach: the cumulative growth rate from 2000 to 2020 of the production variables of the main cultivated flowers in Mexico was calculated; the balance of the country´s floriculture trade balance was evaluated and the Revealed Comparative Advantage Index (RCAI) of the Mexican floriculture sector with respect to the United States of America was estimated. Results: floriculture has expanded in the last two decades, the cumulative growth rates of production variables in most of the flowers studied were positive from 2000 to 2020. National floriculture is a high income activity, in 2020 the four analyzed flowers had a production value of 5.5 billion pesos, up to only 10.11 thousand hectares of land. The trade balance of floriculture in Mexico has been in surplus, the balance of the floriculture trade balance in the country was greater than 90% of the value of exports in most of the analyzed years.  Mexican floriculture is competitive in the international market, in 2020 the RCAI of Mexican flowers in the US market was 0.96 and, in general, in the period studied it has been greater than 0.8. Limitations on study/implications: modifications in the national tariff system that make it difficult to analyze tariff fractions in the evolutionary analysis. The RCAI allows us or not to know the national market, however, it does not establish the factors that provide competitiveness to the country

The objective of this research was to determine the controversial situations in the production of Creole pork in the cooperative sector in Cuba, through the application of a participatory diagnostic system. Interviews were conducted with 50 Creole pig producers belonging to the Cuban Cooperative Organizations of the Holguín municipality. The Vester matrix was used to classify the problems according to their degree of causality, and a SWOT matrix exercise, which was determined through the development of meetings, the application of participatory techniques and group discussions as rural extension work. The 10 main controversial situations were identified, of which four were active problems, four passive, one critical problem and one indifferent. In the evaluated Creole pig breeding systems, the treatment of residuals is null, manure and urine remain in the pens all the time. Reproduction controls are not carried out, affecting the genetic and productive potential. In all cases, the type of reproduction is direct mounting without control. Vaccination and deworming schemes are scarce. One of the demands of the Creole pig breeders surveyed was training in technical, productive and reproductive aspects of animal management.

Objective: Present the current situation of the Cañón del Río Blanco National Park and gathering in a single document all the existing information of this Protected Natural Area (PNA). Design/methodology/approach: Both a bibliographic research and field work were carried out to determine the current state of the PNA. Results: The decree, the geographical location, history of its protection, biological, sociocultural and economic characteristics, environmental services, CONANP work program, environmental problems and category issues are described. Limitations on study/implications: There were no limitations. Findings/conclusions: The area still protects an important biodiversity, also fulfilling vital environmental services, but it is urgent to assign it an adequate category, as well as a director of the park.

In Megamexico the humid forests of the mountain ranges are home to an impressive wealth of orchids, where the epiphytic life forms are significantly more numerous than the terrestrial ones. However, these ecosystems are the most threatened due to anthropogenic activities. In the present, the threats that the forests receive and the repercussions that these imply for the maintenance and conservation of orchids in their natural habitat are described. With the constant threats that forests receive, for example, deforestation, arson fires, changes in land use, etc., epiphytic orchids are the most threatened due to the loss of their habitat and the ecological requirements they need to be able to persist. It is concluded that forest conservation is vital for the maintenance and conservation of orchids, so that in this way, genetic diversity, and ecological interactions between orchid species with other organisms are maintained.