El departamento de La Guajira (Colombia) presenta gran diversidad de especies vegetales, entre éstas, especies halófilas y psamófilas como Ipomoea pes-caprae (L.) R.Br., la cual se distribuye en la zona costera del departamento. Se desconocía si I. pes-caprae produce fenoles en concentraciones lo suficientemente altas, bajo las condiciones ambientales de La Guajira, como para considerar su aprovechamiento; por ende, el objetivo de esta investigación fue establecer la influencia de los periodos climáticos sobre la producción de fenoles totales y el potencial antioxidante de los extractos foliares de esta especie. Se tomaron muestras de tejido foliar durante un año y se sometieron a extracción con metanol. Para establecer la concentración de fenoles totales se utilizó el método de Folin-Ciocalteau y se correlacionó con la precipitación y temperatura mensual. También se estimó el porcentaje de inhibición de los extractos sobre el radical DPPH. Los resultados obtenidos evidenciaron que el contenido de fenoles varió durante todo el año, siendo febrero de 2019 donde se presentó la mayor concentración de estas sustancias (18,41%), coincidiendo con un periodo de bajas precipitaciones y menor temperatura. Por otra parte, la actividad antioxidante de los extractos fue de 83,79%. Se concluyó que la temperatura afecta parcialmente la concentración de fenoles totales, mientras que la precipitación no tuvo efectos significativos; además, este estudio comprueba la posibilidad de utilizar I. pes-caprae como fuente de sustancias con actividad antioxidante de bajo costo y se constituye como base para proyectar futuras investigaciones dirigidas a la evaluación y aprovechamiento de otras convolvuláceas presentes en La Guajira. |  The department of La Guajira (Colombia) presents a great diversity of plant species, among these, halophilic and psamophilic species such as Ipomoea pes-caprae (L.) R.Br., which is distributed in the department coastal area. It was unknown whether I. pes-caprae produces phenols in concentrations high, enough under La Guajira’s environmental conditions, to consider its use; therefore, the aim of this research was to establish the climatic periods influence on total phenols production and antioxidant potential of foliar extracts of this species. Leaf tissue samples were taken for one year and subjected to methanol extraction. To establish total phenols concentration, Folin-Ciocalteau method was used and correlated with precipitation and monthly temperature. Extracts percentage of inhibition on DPPH radical was also estimated. Results obtained showed that phenols content varied throughout one year, with February 2019 showing the highest concentration of these substances (18.41%), coinciding with a low rainfall and lower temperatura period. On the other hand, antioxidant activity of extracts was 83.79%. It was concluded that temperature partially affects the total phenols concentration, while precipitation did not have significant effects; in addition, this study verifies the possibility of using I. pes-caprae as a low-cost source of substances with antioxidant activity and constitutes a basis for future research aimed at the evaluation and use of other Convolvulaceae present in La Guajira

The University of Córdoba, the Faculty of Agricultural Sciences and IBAC have once again fulfilled their mission of disseminating scientific knowledge and contributing to the development of the agricultural sector. The proceedings of these papers will be published in volume 27 of the journal Temas Agrarios, the natural organ of dissemination of the Symposium. Likewise, participation in the III International Symposium and IV National Symposium on Agronomic Sciences, to be held Agronomic Sciences, which will be held in 2023. | La Universidad de Córdoba, la Facultad de Ciencias Agrícolas y el IBAC, han cumplido nuevamente con su misión de difundir el conocimiento científico y contribuir con el desarrollo del sector agrícola. Las memorias de estos trabajos se publicarán en el volumen 27 de la revista Temas Agrarios, órgano natural de difusión del Simposio. Así mismo, se invita a la participación del III Simposio Internacional y IV Simposio Nacional de Ciencias Agronómicas, que realizaremos en el 2023.

The University of Córdoba, the Faculty of Agricultural Sciences and IBAC have once again fulfilled their mission of disseminating scientific knowledge and contributing to the development of the agricultural sector. The proceedings of these papers will be published in volume 27 of the journal Temas Agrarios, the natural organ of dissemination of the Symposium. Likewise, participation in the III International Symposium and IV National Symposium on Agronomic Sciences, to be held Agronomic Sciences, which will be held in 2023. | La Universidad de Córdoba, la Facultad de Ciencias Agrícolas y el IBAC, han cumplido nuevamente con su misión de difundir el conocimiento científico y contribuir con el desarrollo del sector agrícola. Las memorias de estos trabajos se publicarán en el volumen 27 de la revista Temas Agrarios, órgano natural de difusión del Simposio. Así mismo, se invita a la participación del III Simposio Internacional y IV Simposio Nacional de Ciencias Agronómicas, que realizaremos en el 2023.

The department of La Guajira (Colombia) presents a great diversity of plant species, among these, halophilic and psamophilic species such as Ipomoea pes-caprae (L.) R.Br., which is distributed in the department coastal area. It was unknown whether I. pes-caprae produces phenols in concentrations high, enough under La Guajira’s environmental conditions, to consider its use; therefore, the aim of this research was to establish the influence of weather on total phenols production and antioxidant potential of foliar extracts. Leaf tissue samples were taken during one year and subjected to methanol extraction. To establish total phenols concentration, Folin-Ciocalteau method was used and correlated with rains and monthly temperature. Extracts percentage of inhibition on DPPH radical was also estimated. Results showed that phenols content varied throughout one year, with February 2019 showing the highest concentration (18.41%), coinciding with a low rainfall and lower temperature period. On the other hand, antioxidant activity of extracts was 83.79%. It was concluded that temperature partially affects the total phenols concentration, while rains did not have significant effects; in addition, this study verifies the possibility of using I. pes-caprae as a low-cost source of substances with antioxidant activity and constitutes a basis for future research aimed at the evaluation and use of other Convolvulaceae species present in La Guajira.

The reproduction process of Apis mellifera L. (Hymenoptera: Apidae) occurs in defined congregation areas where natural mating occurs and males and unfertilized queen bees from different colonies converge. This work focused on the identification and characterization of a congregation drone zone in a biogeographic region of the low montane dry forest corridor, in the upper Andean valley of Sugamuxi-Tundama, for the density of bee colonies established there, considering the climatic factors of the environment and the description of biometric characters of bees and drones collected, and which constitutes the first report of a congregation zone for Colombia. In the study area, dry summer periods predominate alternating with short winter, cloudy days, and intense cold, with thermal sensations between 8 to 19°C. The drone movement route was established with an unmanned flight vehicle, through the interaction between the vehicle and bee specimens. The path of movement of drones was established operated between 10 and 60 m in North-South direction. Specimens of worker bees were collected identifying African, European, or Eastern European lines and drones of two types, yellow and black, evaluating biometric parameters and estimating the discriminant factor. The activity of the drones, occurs in two periods of 10:00 to 12:00 hours and 15:00 to 17:00 hours, flying regularly between round trips up to a 1 km radius. This work describes a methodology for monitoring congregation areas and consolidates itself as a tool for beekeepers for the conservation of regional ecotypes through bee reproductive planning.

Eucalyptus is the most cultivated hardwood tree genus in the world, valued for its yield and the quality of the wood for multiple uses; however, pathogens such as Rhizoctonia and Cylindrocladium threaten the establishment of the crop, since they cause seedling death in the nursery. Among the management strategies, disinfection of the substrate is recommended, and solarization is an effective alternative for the management of soil fungi. The objective of this research was to verify the survival of Rhizoctonia spp. and Cylindrocladium spp. in a nursery substrate subjected to solarization. The substrate was inoculated with two fungal isolates (Rhizoctonia spp. and Cylindrocladium spp.) at three depths (5, 10 and 15 cm), and treated with three solarization methods (free exposure, solarization and solarization + dazomet). Survival of pathogens in the substrate was measured at 15, 30 and 55 days after inoculation, and temperature at 10 and 15 cm depth. Solarization alone had no effect on pathogen mortality. Solarization plus dazomet decreased fungal presence by 100% at all depths and evaluation times. The solarized treatments increased substrate temperature by 49 and 40°C at 10 and 15 cm depth, respectively, with an increase of 10 and 7°C over the control. Therefore, solarization plus dazomet application can be used as a method of substrate disinfection in Eucalyptus nurseries.

To identify symbiosis between roots and arbuscular mycorrhizal fungi (HMA), methodologies have been reported with variations in concentrations of reagents, temperature, and time of exposure for staining, which does not always adjust to the need for specific cultures due to variation in root structures. The objective of this research was to standardize a methodology to identify mycorrhizal colonization in banana crops in an efficient way. The research was carried out during the second semester of 2022 in the municipality of Apartadó-Antioquia. Four treatments were established that consisted of the evaluation with and without mycorrhizal inoculation with two bleaching techniques each (with and without subjection to Bain Marie). A total of 108 plates (54/technique) were evaluated, where percentage of colonization, visibility, vesicles and arbuscules were identified. There was a complete randomized design. Data were analyzed with R Studio 2022.02 software. An ANAVA and means separations were obtained with a post-hoc analysis of Tukey and Kruskal-Wallis with a confidence level of 95%. Symbiosis was found in all cases, statistical differences were identified in percentage of colonization with 46.8% to 90.2%; arbuscules from 12.1 to 338.0 units and a visibility percentage of 100% in treatments subjected to a Bain Marie, highlighting the need for subjecting banana roots to heat to favor discoloration, staining and visibility due to their architecture.

The biotic interaction between plants and endophytic fungi strengthens the adaptive capacity of the hosts against environmental disturbances, and confers nutrition and protection benefits to the associated microorganisms. Studies associated with endophytic fungi report their presence in the greatest diversity of existing plants. In hosts such as Cannabis, the interaction with endophytic fungi favors the production of secondary metabolites and phytohormones that participate in obtaining organoleptic properties such as flavors and aromas. However, the research carried out in the Vanilla genus is scarce, making it difficult to understand the functions that these microorganisms can perform for the benefit of the host. In relation to Vanilla, the fruits of species within the aromatic clade are distinguished by the presence of aromatic compounds, which increase their content during ripening. Some studies have shown that in the fruits of this orchid there are endophytic fungi possibly associated with the ripening process that is accelerated by curing, but few of these studies have evaluated the activity of these fungi related to the natural ripening of the fruit. In this review, scientific literature related to the knowledge of fungal endophyte communities and their possible contribution to the ripening and production of aromatic compounds in vanilla fruits is compiled. Research opportunities are identified to develop future studies on the role of fungal microorganisms in obtaining metabolites and aromatic precursors from the fruits of Vanilla species, both in wild conditions and in commercial crops.

The crop of medicinal cannabis has developed great importance in recent years in Colombia and other Latin American countries. Considering the production characteristics of the crop, which is fundamentally based on organic models, it is important to know the microorganisms that accompany the production system and their possible implications for management. In this research were isolated and characterized the microorganisms in the different phases of production of a high-density cannabis crop: planting, or propagation areas, production areas, and postharvest areas (flower pre-drying). In each area samples of soil, substrates and water were taken and the microorganisms present were identified by direct sowing in culture media, using microscopic identification and molecular characterization. A high diversity was found in all production areas, and it was evidenced that beneficial microorganisms (Trichoderma spp. and Bacillus spp.) applied to the production system regulate the populations of microorganisms in the soil and in the substrates. It was identified that perlite and coconut fiber allow the development of populations of phosphorus solubilizing and nitrogen fixing microorganisms and that the production of compost using crop waste is safe at a sanitary level. No populations of pathogens were identified in any of the samples evaluated at levels that could explain the presence of diseases in the crop.

Grown in different regions of Brazil, mango is of great importance at the national level. However, mango cultivation is directly related to physiological factors such as photosynthesis, stomatal conductance and chlorophyll. Physiological factors are related to the nutritional balance of the plant. Among the nutrients, potassium (K) can be highlighted, which, despite not being a structural element for the plant, stimulates, or is part of several physiological plant processes. Therefore, an experiment was carried out with the purpose of evaluating, in the vegetative period of 'Palmer' mango, the effect of different sources of K to accelerate the maturation stage of mango branches and verify their influence on physiological indexes and chlorophyll. Treatments consisted of three ripeners and a control, which were applied directly to the branches and leaves of “Palmer” mango trees. The variables analyzed were chlorophyll A, B and Total indexes; Internal concentration of CO2; Stomatal conductance; transpiration rate; Net photosynthesis; Instantaneous Carboxylation Efficiency and Water Use Efficiency. After collecting, and analyzing the data, it was concluded that the vegetative period of the “Palmer” mango tree, in relation to the different evaluation dates, was not influenced by potassium sources. The use of T4 treatment (SpeedFol® induction mango) can provide a greater increment of chlorophyll A, B and Total than KCl and K2SO4.