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

Introduction. Chionanthus pubescens Kunth is an endemic tree of southern Ecuador with ornamental uses in the villages of the region due to its pink inflorescence. Objective. To evaluate the effect of aqueous extracts of quinoa mojuelo (Chenopodium quinoa Willd.) on the growth of arupo plants (Chionanthus pubescens Kunth) and the incidence of Fusarium sp. Materials and methods. The trial was conducted in the province of Chimborazo, Ecuador, during 2022. Aqueous extracts of quinoa mojuelo were obtained using the Soxhlet method, and their concentrations were determined by UV-VIS spectrophotometry. A completely randomized block design with a bifactorial arrangement was used, with three levels for factor A (aqueous extract of mojuelo: mother extract at 100%, and 50 % and 75 % dilutions in sterile distilled water; v/v) and three levels for factor B (application frequency: every 7, 14, and 21 days). Ten treatments were evaluated, including an absolute control, with three repetitions each. In ten randomly selected plants per treatment, morphological variables (height, number of leaves per plant, and stem diameter) were measured, as well as the incidence of Fusarium sp. Results. The 50 % and 75 % aqueous extract concentrations applied weekly promoted better morphological development and reduced the percentage of Fusarium sp. incidence in arupo plants, as reflected in height (16.3 cm), number of leaves (17.8), stem diameter (6.5 cm), and disease incidence (50 %). Conclusions. Aqueous extracts obtained from quinoa mojuelo applied to Chionanthuspubescens Kunth plants in nursery conditions reduced the incidence of Fusarium wilt and favored their growth in the early stages of development.

Introduction. The charcoal rot fungus, Macrophomina phaseolina, is a ubiquitous necrotrophic phytopathogen that infecting soybean and other plant species. Despite its significant impact on crops, limited progress has been made in understanding the factors that influence phytotoxic molecule secretion by this phytopathogen. Objective. To evaluate the effect of soybean leaf infusion in the culture medium on the differential secretion of phytotoxic molecules of M. phaseolina. Materials and methods. The study was conducted between 2016 and 2023 at the Departamento de Química Biológica, Universidad Nacional de Asunción, Paraguay. Two fungal isolates were cultured in vitro using potato dextrose broth (PDB) and Czapek-Dox broth media, with or without soybean leaf infusion. Phytotoxic activity of secreted molecules was a using soybean leaf discs. The crude organic extract from the cultures was separated using chromatographic techniques, and purified metabolites were characterized by UHPLC-PDA/MS, HRMS (APGC), HRMSESI, 1HNMR and 13CNMR. Results. Molecules secreted by M. phaseolina FCQ11 cultured in infusion-enriched PDB induced the highest percentage of necrosis. Under these conditions, three differentially secreted metabolites were isolated and identified: (R)-mellein, (3R,4R)-hydroxymellein, and (-)-botryodiplodin. Conclusions. Soybean leaf infusion presence in M. phaseolina growth media stimulates phytotoxic metabolite production and alters the profile of secreted metabolites.

Introduction. The rearing of guinea pigs (Cavia porcellus) is key to the food supply and economy of Andean countries such as Peru. However, their productivity may be affected by inadequate management, including stocking density, whose impact has not yet been fully evaluated. Objective. To evaluate the productive efficiency of guinea pigs subjected to high stocking densities. Materials and methods. The experiment was conducted at the Small Animal Laboratory of the National Agrarian University La Molina (UNALM) in Lima, Peru, over eight weeks (January to March 2022). A total of 90 improved male guinea pigs of the Cieneguilla-UNALM genotype were used, with an average initial weight of 338.57 g (15 ± 3 days of age). The experimental design was completely randomized, with three treatments: 0.10 m²/animal (T1), 0.066 m²/animal (T2), and 0.050 m²/animal (T3), with three replicates of ten guinea pigs each. The animals were fed ad libitum with balanced feed and forage, with continuous access to water. The evaluated productive variables included initial and final weight, weight gain, feed intake (daily, weekly, and total), feed conversion ratio, mortality, carcass lesions, visible fat scoring, and carcass yield. Results. Treatment T1 showed the highest weight gain and total feed intake, while T3 exhibited the best feed conversion ratio and the lowest mortality among the productive variables. Carcass yield and visible fat content were higher in T1; however, T3 showed fewer signs of carcass lesions (p < 0.05). Conclusions. Stocking density in guinea pigs did not significantly affect the evaluated parameters, including weight gain, feed intake, feed conversion ratio, mortality, fat scoring, and carcass yield. However, the highest density (T3) reduced the incidence of lesions, indicating lower competitive behavior among the animals.

Introduction. In the dairy industry, frozen-thawed semen is crucial for artificial insemination and genetic improvement of cattle. Objective. To evaluate the variation in the kinematic subpopulation structure of frozen-thawed semen in Jersey and Holstein breeds using a CASA-mot system. Materials and Methods. The study was conducted from April to November 2023, at the Animal Reproduction Laboratory (AndroTEC), located at the Campus Tecnológico Local San Carlos, Alajuela, Costa Rica. Eight animals from the Holstein and Jersey breeds were used, and nine doses of frozen-thawed semen per animal were analyzed for each breed. A total of 72 semen doses from eight bulls (four from each breed) were thawed at 37 °C for 30 s. Sperm motility and kinematic variables were analyzed using CASA-mot (Computer-Assisted Semen Analysis) technology. Results. The Jersey breed presented higher percentages of total motile, progressive motile, and rapid spermatozoa compared to the Holstein breed (P < 0.05). Principal component analysis revealed two significant factors explaining 87.5 % of the total variance in kinematic variables. The kinematic variables between sperm subpopulations (SP) showed differences (P < 0.05) in both breeds. Subpopulation SP2 was the fastest, with higher values for curvilinear speed (VCL), straight-line speed (VSL), and average trajectory speed (VAP) in both Holstein and Jersey bulls. Conclusions. Kinematic differences were found between the identified subpopulations in both breeds. The kinematic patterns of the subpopulations present in the ejaculate could influence fertility and reproductive performance.

Introduction. Coffee cultivation in Ecuador plays a crucial role in social, economic, environmental, and cultural aspects. In Loja province, Coffea arabica production is distinguished by its high quality, attributed to both the geographical conditions and the cultivation practices under agroforestry systems (AFS) with different management approaches. Objective. To assess the composition, diversity, and importance value of shade tree species, and to identify the microclimatic conditions within coffee agroforestry systems. Materials and methods. The research was conducted in three coffee-producing areas of Loja, Ecuador, using 20 × 30 m plots monitored from November 2017 to April 2019. The importance value index (IVI), Shannon-Wiener, and Simpson indices were calculated. Microclimatic variables, including ambient temperature (°C), relative humidity (%), wind speed (m s⁻¹), and canopy cover percentage (%), were recorded both inside and outside the AFS. Pearson correlation analysis was used to examine relationships between microclimatic variables, number of shade-providing individuals, and their importance value. Results. The coffee-growing areas exhibited significant arboreal diversity in terms of families, genera, and shade tree species, with Citrus and Inga as predominant genera. Microclimate modifications were evident, with temperature differences (ranging from −4.23 °C to 2.23 °C) and relative humidity variations (ranging from 0 % to 10.54 %) compared to full-sun exposed areas. Conclusions. Coffee AFS modify environmental conditions between the interior and exterior of the evaluated areas, with variations directly influenced by canopy species within the systems.

Introduction. Insect-based foods represent an emerging alternative to conventional food products. Insect powders are an important protein source with reduced ecological impact, though its incorporation into foods should consider effects on sensory properties and nutritional profiles. Objective. To assess consumer acceptance of sweet biscuits with cricket powder in Costa Rica, and evaluate the nutritional profiles of the products developed. Materials and methods. The study was conducted at the Universidad de Costa Rica, San José, Costa Rica in 2023. Sweet biscuits containing varying proportions of cricket powder (0.0, 12.5, and 26.0 %) were manufactured to evaluate both placebo effect and effect of cricket powder content influence on consumer acceptance, using two distinct panel groups. Demographic information, attitudes towards entomophagy, and perceived importance of protein consumption were collected via questionnaire. Proximate analysis and detailed fatty acid composition were performed on the three tested formulations with cricket powder. Results. Study populations demonstrated positive attitude towards insect consumption. The overall acceptance of the “No cricket” sample was significantly lower compared to both “Cricket” and “Commercial” samples. Biscuits containing 12.5% cricket powered achieved significantly higher overall sensory acceptance compared to the “26.0 % cricket powder” sample and showed no significant difference from the “Commercial” sample. Consumer segmentation was accomplished through Agglomerative Hierarchical Clustering. Primary nutritional differences between samples were observed in crude fat and specific fatty acids contents. Conclusions. Results indicate high consumer acceptance of sweet biscuits with cricket powder in Costa Rica. Nutritional analysis revealed progressive increases in crude fat and specific fatty acids contents corresponding to increased cricket powder incorporation.

Introduction. Quality seed production is a limiting factor for bean cultivation in developing countries. Objective. To evaluate the effects of sun-drying at different exposure periods on the viability and vigor of bean seeds cv. ‘Cuba Cueto 25-9N’. Materials and methods. The study was conducted at the University of Artemisa, Cuba, from January to May 2024. Freshly harvested bean seeds cv. ‘Cuba Cueto 25-9N’ were sun-dried on jute sacks under three drying durations (24, 48, and 72 h) post-treatment seed moisture content and germination were evaluated as viability criteria. Vigor assessment included germination dynamics, emergence rate, electrical conductivity, and accelerated aging test. Data were analyzed using analysis of variance and means were compared using the Tukey’s test (p ≤ 0.05). Results. The 24 and 48 h drying treatments reduced seed moisture to levels that maintained both viability (92.66 and 84.33 % germination, respectively) or vigor. The 72 h drying treatment decreased moisture to 2.96 %, negativelyaffecting viability and vigor. Conclusions. Sun-drying of bean seeds for 24 and 48 h effectively reduced moisturewhile maintaining viability and vigor, contributing to the preservation of their physiological quality under resourcelimitedconditions. The 24 h treatment proved most efficient.

Introduction. Weeds compete with coffee for water, light, and space; therefore, sustainable management practices must be implemented. Objective. To evaluate the effectiveness of weed management with ammonium nitrate and flaming in a coffee system. Materials and methods. This study was carried out from September 26, 2022, to January 10, 2023, at La Hilda coffee farm in San Pedro de Poás, Alajuela, Costa Rica. Two alternative weed control treatments were applied jointly: the first consisted of ammonium nitrate diluted in water at three doses (0, 150, and 300 kg/ha), followed 15 days later by flaming at three doses (0, 60, and 120 kg/ha). Applications targeted weeds present in the coffee rows, using a split-plot design where the main plot consisted of the ammonium nitrate doses and the small plots corresponded to flaming doses. A chemical control treatment with glyphosate, also combined with flaming, was included. Each treatment was randomly assigned and replicated six times. Results. Broad leaves were moderately damaged 25 days after nitrate application and 10 days after flaming. Both doses of ammonium nitrate without flaming caused slight damage to Commelina diffusa, and the highest ammonium nitrate dose without flaming produced moderate damage to broadleaf weeds; flaming without ammonium nitrate resulted in moderate initial damage to narrowleaf weeds. Conclusions. The herbicidal effect of ammonium nitrate was depended on flaming, but this effect was only observed in broadleaf weeds. C. diffusa was successfully controlled with glyphosate and flaming.

Introduction. Sansevieria anthracnose, caused by Colletotrichum sansevieriae, represents a significant risk to the cultivation and export of this ornamental plant. Effective and rapid identification methods for this pathogen are crucial for implementing control measures to prevent its spread to uninfected areas. Objective. To implement and optimize molecular methods for the rapid and reliable identification of C. sansevieriae. Materials and methods. During 2016, a β-tubulin-2 (β-tub2) gene fragment of C. sansevieriae isolated from a local farm in Alajuela, Costa Rica, was analyzed. PCR-RFLP of the partial β-tubulin-2 (β-tub2) gene fragment was implemented using the enzyme MseI (Tru1I). In addition, species-specific primers for C. sansevieriae detection and PCR-RFLP analysis of the amplified fragment were applied. Results. The digestion consistently produced a two-band restriction pattern specific to C. sansevieriae. The designed primers successfully amplified a 383 bp fragment of the β-tub2 from all C. sansevieriae strains tested. No amplification was observed from other Colletotrichum species within the C. gloeosporioides and C. acutatum complexes, as well as from C. truncatum and Fusarium oxysporum isolates. Moreover, this restriction site, located within the amplicon generated by the species-specific primers for C. sansevieriae, enabled successful validation of the species through digestion. Conclusions. Both PCR based methods demonstrated sufficient sensitivity to detect C. sansevieriae in naturally and artificially infected Sansevieria leaves without the need to isolate the pathogen in pure cultures, making the diagnostic process more efficient and accessible.

Introduction. Plant pigments represent an alternative to artificial colorants and contribute to the consumption of healthier foods. Objective. To evaluate, both in field and laboratory, exploratory single crosses (ESCs) of maize purple grain and cob developed using random lines, to assess the integration of the heterotic pattern B-49N x B-41N. Material and methods. The research was conducted in Tepatitlán, Jalisco, Mexico, during 2021 and 2022. ESCs were formed using six S5 lines from the B-49N population and four S3 lines from B-41N, all with purple grain and cob. In 2022, the crosses and five controls were evaluated under rainfed conditions in the same location, using a randomized complete block experimental design with three replications. Each plot consisted of a single row, 4 m long, 0.8 m wide, and 0.16 m between plants, with 25 plants per row. Data were collected on plant and ear characteristics. Total anthocyanin content in grain (CATg) and cob (CATo) was measured in seven of the crosses. Analysis of variance and mean comparison tests were conducted for all variables using SAS statistical software. Results. Twelve ESCs were identified with grain yield equal (p < 0.05) to the white control, but with purple grain and cob. Significant variation (p < 0.05) was observed in days to anthesis (ranging from 80 to 90 days), stalk lodging (from 0 to 12.6 %), and ear scoring (from 1.5 to 2.7). Grain texture ranged from soft to very soft among the ESCs. No association was found between grain yield and levels of CATg and CATo. Conclusion. The results from the ESCs indicate positive progress in the integration of the purple maize heterotic pattern B-49N x B-41N. However, future efforts should focus on increasing anthocyanin content in grain and cob, as well as improving grain hardness.