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

ABSTRACT Objective: The objective of this research was to determine the importance of the harvest time, on the physical quality and viability of the seed by means of the tetrazolium test. Design/methodology/approach: The research was conducted under a completely randomized experimental design, the viability in embryos was taken based on a 5-color staining pattern. An analysis of variance and the comparison of means by Tukey (P? 0.05) were performed with the SAS 9.2 program. Results: The varieties under study showed significant differences in all the variables studied related to physical quality of seeds, such as volumetric weight and weight of 1000 seeds. The best seed viability was obtained in the harvest season of January. Limitations of the study/implications:The results obtained are limited to the varieties, environmental conditions and the time in which the varieties were evaluated. Conclusions: The harvest time has an effect on better seed physical characteristics and better viability evaluated with tetrazolium in the seeds of coffee varieties.

Objective: To identify the success and business resilience factors of rural companies, through an analysis of rural companies in Mexico, in order to contribute to the differentiation of these concepts. Methodology: The companies of the National Network for Sustainable Rural Development were used as a case study, who were asked key questions to identify their factors of success and business resilience. Results: The main success and resilience factors of these companies were identified; Permanent job creation turned out to be the main success factor and punctuality in order delivery was the most identified resilience factor. Implications: Identifying and recognizing the difference between the two factors can help companies and their leaders or executives understand and adjust their strategies based on their objectives: to be successful or to be resilient. Conclusions: There is a difference between a success factor and a business resilience factor; a success factor is a way of standing out among similar companies, while a business resilience factor is used to face adversities and continue over time.

Objective: to study the heterosis and agronomic performance of raspberry F1 families derived from open-pollinated parents, and to investigate the heterotic relationships between yield and its components. Design/methodology/approach: A total of thirty-five genotypes, including eight open-pollinated raspberry cultivars, their 28 F1 families, and one check, were evaluated for vegetative and fruit traits. The trial was carried out under a randomized block design and under open field conditions. Results: Mid-parent heterosis ranged from -94.83 to 311.67 %, whereas the better parent heterosis values varied from -94.26 to 235.00 %. We observed that the heterosis values for yield had a strong and positive correlation (r = 0.89) with the heterosis values for number of fruits per plant. Limitations on study/implications: heterosis and performance of F1 families in raspberry would depend on the pedigree of parents as their relativeness is a key factor to exploit the heterosis in plants. Findings/conclusions: High values of heterosis were found in some raspberry crosses. Progeny derived from parents MU1 and TD865 showed considerable mid-parent heterosis and good performance for fruit size-related traits, soluble solids content, and yield, evidencing that both parents may be utilized as donor parents in a raspberry breeding program.

Objetive: To determine soil quality under two contrasting agricultural management practices, based on microbial biomass and earthworm density, as compared to untilled control soils in two seasons (dry and wet), in different production units of small-scale milk production systems. Methodology: The work was conducted in ten production units in the municipality of Aculco, Estado de México, Mexico. We analyzed physical, chemical, and biological soil indicators (microbial biomass and earthworm density). We conducted an ANOVA with a 3 x 2 factorial arrangement (three systems [maize, grassland, and control] and two seasons [dry and wet]). Results: Values for all quality indicators in maize-cultivated soils were low, but increased in the wet season. Parameters in pasture-cultivated soils were similar to control soils. Implications: These results determine the conditions of the soils used in milk production systems. Conclusions: Some of the parameters assessed can be used as indicators of soil degradation and to strengthen other indicators which lead to an improved assessment of these systems’ sustainability

Objective: Characterize double-purpose bovine production units (PU), and identify the sanitary management used by producers in their herds. Design/methodology/approach: 60 cattle producers were interviewed, the questions were related to the characteristics of the PU and the health status. Four serum samples were sent to the laboratory of the largest herd. Results: All the cattle producers surveyed were males between the ages of 20 and 50. 40% have been engaged in the activity between 11 and 25 years. The PU have an average of 25 animals, 45% of the producers have between 21 to 30 cows, the highest percentage of animals are Gyr breed (35%) and Sardo Negro (30%). 65% of the producers take care of their sick animals. On the other hand, laboratory studies showed that three cows were positive for Bovine Respiratory Syncytial Virus (BRSV), two positive cows for bovine herpesvirus type 1 (BoHV-1) or Infectious Bovine Rhinotracheitis (IBR) and Parainfluenza 3 (PI3), finally all cows tested positive for Leptospira sp hardjo. Study limitations/implications: Under the conditions in which the study was conducted, it is expensive to send samples to the laboratory. The producer with the largest herd financed the laboratory tests of the sampled cows. This information is useful for local producers regarding the characteristics in which they produce. Findings/conclusions: Dual-purpose cattle producers in the tropics produce on a small scale; and one of the largest PUs has problems of abortive diseases.

Objective: To perform in vitro and in situ evaluation of a diet for dairy cattle with fish oil and soybean oil at different proportions. Design /methodology /approach: Four treatments with different proportions of fish oil (FO) and soybean oil (SO) were evaluated (Control: no added oil, diet 1: 2% FO, diet 2: 2% FO and 1.5% SO, diet 3: 2% FO and 3% SO). In vitro digestibility and in situ degradability were evaluated. Ammonia nitrogen, lactic acid, volatile fatty acids (VFAs), and microbial protein were determined. For the in situ evaluation, a protein degradability kinetic was carried out. The means were compared by Tukey's test at a 5% confidence level. Results: The proposed diets increased gas production in in vitro kinetics as the addition of oils increased (p <0.001) and the kinetic latency time decreased (p <0.001). All diets decreased the production of short chain fatty acids (p <0.001), the production of ammonia nitrogen and lactic acid did not differ compared to the control (p <0.05). Diet 3 presented a higher production of propionic acid in comparison to diet 1 and 2. In the in situ kinetic, the "kd" rate increased as the addition of the oils increased. Study limitations /implications: Although the production in milliliters of  and  increased in all treatments, it is an upsurge proportional to the gas production given by a better use of the diets. Findings /conclusions: The addition of oils produced changes in the fermentation patterns and in the degradation of the protein at the ruminal level, increasing the bypass protein. Which offers an opportunity to improve performance in certain production situations.

Objective: To phenotypically and molecularly characterize and identify the causal agent of onion (Allium cepaL.) bulb rot in Morelos, Mexico.Methodology: Fluorescent bacteria from onion bulb tissue with symptoms of rot were isolated; the LOPATtest was used to describe them and subsequently they were identified by partial 16S rRNA gene amplification.Pathogenicity in vegetables and plants was evaluated injecting a suspension with 108 CFU mL-1of the pathogen.Results: Phenotypic characterization and 16S rRNA nucleotide sequencing showed 100% identity withPseudomonas viridiflava as the causal agent of onion bulb rot. The pathogen caused infection in broccoli (Brassica oleracea L.), spring onion (Allium fistulosum L.), purple onion (Allium cepa L.), cauliflower (Brassica oleracea var. botrytis L.), leek (Allium porrum L.), and carrot (Daucus carota L.), as well as in plant species such as jalapeño pepper (Capsicum annuum var. annuum L.), bean (Phaseolus vulgaris L.), and tomato (Solanum lycopersicum L.).Implications: This information is important for agriculture in Mexico. Pseudomonas viridiflava is a bacterialpathogen with high potential to infect new hosts. This is the first report of P. viridiflava causing onion rot in Mexico.Conclusions: Pseudomonas viridiflava is the causal agent of onion bulb r

Objective: Analyze the commercial competitiveness of Mexican mango in the world market, by determining the growth rates of mango exports, imports, and production, as well as the commercial competitiveness indices. Design / methodology / approach: The production was obtained from the Agri-Food and Fisheries Information Service (SIAP), exports and imports from the International Trade Center of UNCTAD / WTO through TRADEMAP; The relative trade balance, the tradability index, the degree of export openness and the degree of import penetration were measured. Results: The relative trade balance index of Mexico, which was very close to 1. With respect to the tradability index, it was 0.2 on average. The degree of export openness was positive in all years. The import penetration degree index found that the values ​​were very close to 0. Exports grew by 97% and imports by 30%. Limitations / Implications: Statistical records for the period from 2005 to 2018 were considered; considering all the mango varieties produced and exported. Findings / conclusions: Mango is a primary product appreciated worldwide, which is why the demand for this product has been growing. Exports had a growing behavior. Imports are very few in relation to exports, in all years the positive trade balance. Mexico evidenced an increase in competitiveness at the international level.

Objective: Determine the water quality in the central zone of the Texcoco aquifer for human use and consumption and agricultural use. Methodology: Physical, chemical and biological indicators of the water from 16 wells located in urban areas of the central zone of the aquifer were determined. Sampling, determination of the parameters and definition of its quality by uses was made based on current official Mexican standards. Results: According to the physical indicators and the concentrations of CO32-, HCO3-, Ca2+, Mg2+, Cl-, SO42-, PO43-, Na+, K+, Fe, Cu and Zn, the water was suitable for human consumption and agricultural use in the 16 wells studied. Based on the Cadmium concentration (Cd), the water was unsuitable for human consumption and agricultural use, in 12 and 6 wells, respectively. According to the found concentration of Lead (Pb), the water was suitable for agricultural use in the 16 wells studied, but in all of them it was not suitable for human consumption. Water did not meet the microbiological quality required for human consumption in eight of the wells analyzed, but was suitable for agricultural use in all the study wells. Implications: This study complements the research carried out in other areas of the aquifer. The causes of water contamination are unknown and it would be convenient to investigate the vulnerability of the aquifer and possible sources of contamination. Conclusions: The aquifer water in the central zone has limitations for human use and consumption and agricultural use due to the high concentrations of Cd, Pb and poor microbiological quality.

Objective:  determine the presence of zoonotic pathogens in chicken meat sold in retail centers in five cities of the Mexican Republic. Design/methodology/approach: 153 samples of raw chicken meat were analyzed. All samples were analyzed using methods approved by the AOAC and the US regulatory agencies, isolation that what promised, slipped and subsequently PCR analysis was performed for Campylobacter spp., Salmonella spp., E. coli and Listeria spp. Results: Campylobacter spp. it was found in 31% of the samples and Salmonella spp. in 1.31% of the total samples analyzed. Campylobacter spp. it has a higher prevalence in Tlalnepantla Estado de Mexico (74%), Puebla (33.33%) and Guadalajara Jal. (25.58%). Salmonella spp. it has a higher prevalence in Tlalnepantla Estado de Mexico (3,7%) and Guadalajara Jal. (4,65%). sites. Limitations: This study describes the prevalence of Campylobacter and Salmonella in chicken meat for sale in Mexico, however, more studies are needed to determine exactly the origin of these bacteria. scale. Findings/conclusions:  According to the results obtained in this work, it can be concluded that there is contamination of the chicken meat with the bacterium Campylobacter spp. in a higher proportion, unlike Salmonella spp. This may be due to possible errors in the handling in the different areas by which the bird is handled from the farm to the commercialization.