Envíos recientes

The Valencia Orange (Citrus sinensis The Valencia Orange (Citrus sinensis (L.) Osbeck.) is the most cultivated in the citrus regions of the world as well as in Colombia, being the subtropical regions responsible for more than 85% of the world production. The Valencia Orange is of great importance in Cordoba due to its wide consumption and also because of its high nutritional content such as vitamin C, which helps to absorb other nutrients. In Colombia, small producers of plants for planting in the citrus area are unable to comply with the requirements of Resolution 12816 of 2019, mainly because of the costs involved in maintaining large mother plants under net house conditions. This research was carried out in the Laboratory of Vegetal Biotechnology of the Faculty of Agricultural Sciences of the University of Cordoba, municipality of Montería in the department of Cordoba, and its main objective was to evaluate the efficiency of three mini-grafting techniques in the production of orange Valencia plants. The rootstocks were obtained from cleopatra mandarin seeds (Citrus reshni Hort ex Tan) evaluating different conditions for germination. The seeds that were scarified achieved the best result with 100% germination. There were statistically significant differences between the evaluated treatments (P0.05). Three mini-graft methods were evaluated (inverted T, cleft and terminal bud) with 20 repetitions for each treatment, the cleft method obtained the highest percentage of successful mini-grafts (75%), followed by the inverted T method (37.2%), the method that obtained the less favorable data was terminal bud (0%). Bud length (cm) and number of leaves were evaluated. Bud length was analyzed with a Student t-Test for independent samples, where no significant differences were observed (P>0.05), for number of leaves a non-parametric Wilcoxon Test for independent samples was used. Significant differences between treatments were observed (P (L.) Osbeck.) is the most cultivated in the citrus regions of the world as well as in Colombia, being the subtropical regions responsible for more than 85% of the world production. The Valencia Orange is of great importance in Cordoba due to its wide consumption and also because of its high nutritional content such as vitamin C, which helps to absorb other nutrients. In Colombia, small producers of plants for planting in the citrus area are unable to comply with the requirements of Resolution 12816 of 2019, mainly because of the costs involved in maintaining large mother plants under net house conditions. This research was carried out in the Laboratory of Vegetal Biotechnology of the Faculty of Agricultural Sciences of the University of Cordoba, municipality of Montería in the department of Cordoba, and its main objective was to evaluate the efficiency of three mini-grafting techniques in the production of orange Valencia plants. The rootstocks were obtained from cleopatra mandarin seeds (Citrus reshni Hort ex Tan) evaluating different conditions for germination. The seeds that were scarified achieved the best result with 100% germination. There were statistically significant differences between the evaluated treatments (P0.05). Three mini-graft methods were evaluated (inverted T, cleft and terminal bud) with 20 repetitions for each treatment, the cleft method obtained the highest percentage of successful mini-grafts (75%), followed by the inverted T method (37.2%), the method that obtained the less favorable data was terminal bud (0%). Bud length (cm) and number of leaves were evaluated. Bud length was analyzed with a Student t-Test for independent samples, where no significant differences were observed (P>0.05), for number of leaves a non-parametric Wilcoxon Test for independent samples was used. Significant differences between treatments were observed (P<0.05), with 3 and 5 leaves on average.

Se presenta los resultados de una investigación realizada con el propósito de fortalecer las competencias científicas en la enseñanza y aprendizaje de las Ciencias Naturales en los estudiantes de grado 9º mediante el diseño e implementación de una unidad didáctica sobre biodiversidad. En la educación básica secundaria es fundamental desarrollar las capacidades como la curiosidad, el deseo de conocer, plantearse preguntas, observar, criticar, reflexionar y solucionar problemas, acciones propias del acto científico. Inicialmente se realizó una evaluación centrada en el desempeño de la competencia científicas para lo cual se aplicó un cuestionario diagnóstico que contiene la contextualización de conceptos y problemáticas relacionadas con la biodiversidad, desde el reconocimiento de esta como patrimonio y la promoción de acciones para el cuidado y la conservación del entorno y sus recursos naturales. Con una metodología cualitativa y el método estudio de casos único, se emplearon técnicas como cuestionario diagnóstico, entrevistas semiestructuradas, observación participante y análisis de organizadores gráficos. Los resultados evidencian el dominio de habilidades por parte de los estudiantes como el establecimiento de relaciones entre conceptos, leyes y teorías, interpretación de gráficas y planteamiento de hipótesis, así como un dominio básico de los contenidos relacionados con biodiversidad, limitado a la variedad de organismos; demostrando que se requiere fortalecer, en los estudiantes, la competencia de uso comprensivo del conocimiento científico. Así mismo, se presentan resultados en cuanto a la sistematización, estructuración, diseño y aplicación de algunas de las actividades de las unidades didácticas que evidencio el fortalecimiento de las competencias científicas, especialmente del uso comprensivo del conocimiento científico, y la apropiación de la Biodiversidad, incentivando actitudes enfocadas al reconocimiento y su conservación.

In Córdoba state, Colombia, there is little information on the contribution of silvopastoral systems to the physical, chemical, and biological properties of soils, in addition to this, ecological balance and animal welfare. The objective of this investigation was to evaluate the effect of the litter of forest species in silvopastoral arrangements on some properties indicative of soil quality. The research was carried out under a completely randomized block design with four treatments T1= Brachiaria cv. Mulato II, T2= Tabebuia rosea + Brachiaria cv. Mulato T3= Acacia mangium + Brachiaria cv. Mulato II, T4= Gmelina arbórea + Brachiaria cv. Mulato II, with three repetitions, through: 1). Determination of the litter production and the potential contribution of nutrients during 7 months, obtaining highly significant differences, being the forest species G. arborea and A. mangium those that obtained the highest litter production with 6938.1 and 5945.5 kg ha-1 respectively, followed by T. rosea with 3912.6 kg ha-1 and finally Mulato II with 2264.6 kg ha-1 . Regarding the potential contribution of the evaluated nutrients, the highest content of Nitrogen (N) in the leaf litter was recorded in the species G. arborea and A. mangium, with 70.77 kg ha-1 and 62.45 kg ha-1 respectively, while Mulato II recorded a value of 9.97 kg ha-1 . For the phosphorus nutrient (P), the highest values were obtained in G. arborea with 14.57 kg ha-1 and T. rosea with 5.48 kg ha-1 , while Mulato II registered 5.67 kg ha-1. For its part, calcium (Ca) and potassium (K) presented their highest content in G. arborea with 96.47 kg ha-1and 37.48 kg ha-1 , respectively, unlike Mulato II with 9.75 kg ha-1 and 14.51 kg ha-1 respectively. two). Litter decomposition rate evaluation for 7 months, where the results showed a highly significant difference between the average residual dry mass (MSR) of the litter of the A. mangium species, with the highest record, followed by T. rosea, G arborea and finally Mulato II, with the 0.74, 0.66 0.59 and 0.56 respectively. The decomposition speed showed that Mulato II and G. arborea exhibited the highest decomposition rate (k) with a value of 1.87 and 1.77 respectively, indicating an inverse relationship between these variables (MSR and k). 3). Determination of physicochemical properties with significant differences in organic matter between the SSP with T. rosea (4.43%) and A. mangium (4.33%), with respect to the Mulato II pasture (3.3%). The lowest record of mechanical resistance to penetration was obtained in Mulato II (1.62 MPa), followed by SSP with A.mangium (1.74 MPa), T. rosea (1.82 MPa) and G. arborea (1.85 MPa). The soil variables that did not register significant differences were bulk density, phosphorus, calcium, magnesium, potassium content and pH. These results allow us to conclude that silvopastoral arrangements contribute to the improvement of soil quality through the recycling of nutrients, becoming a clear alternative to traditional pasture systems.

El presente estudio propone una estrategia etnoeducativa desde los saberes ancestrales de la etnia Emberá Katío sobre el cuidado del medio ambiente para el área de Ciencias Naturales y Educación Ambiental del grado 5 básica primaria sede Volador de la Institución Educativa los Morales de Tierralta– Córdoba. Mediante un diseño etnográfico con enfoque cualitativo, se aborda una muestra de 14 estudiantes indígenas, 1 docente occidental, 2 docentes Emberá Katío y 5 miembros de la comunidad Doza (el Jaibaná, Alguacil, Hierbatero, Cazador y Anciano). A partir de la aplicación de las técnicas de observación, entrevista y grupo focal se caracterizaron los saberes ancestrales de la etnia Emberá Katío comunidad Doza sobre el cuidado del medio ambiente, dando posibilidad de interpretación reflexiva que contribuyó al diseño de una estrategia etnoeducativa con cinco talleres que hacen énfasis en las categorías que emergieron de las interpretación de los resultados como el Territorio, Plantas medicinales, Alimentación, Chagra y Memorias, para ser implementada bajo el método Reflexión- Acción-Participación (RAP) en el área de Ciencias Naturales y Educación Ambiental básica primaria.