Examinando por Materia "Susceptibility"
Mostrando 1 - 2 de 2
Resultados por página
Opciones de ordenación
Publicación Acceso abierto Evaluación de la resistencia de genotipos de frijol caupí (Vigna Unguiculata L.) a marchitez por Sclerotium Rolfsii en casa malla(2023-02-28) Urango Esquivel, Naudith; Campo Arana, Rodrigo OrlandoThe cowpea bean crop in Colombia is of great importance, mainly in the Caribbean region, being a basic agricultural alternative in the diet of low-income households; however, one of the limitations of the crop is the presence of the phytopathogenic fungus Sclerotium rolfsii Sacc. which causes yield losses of up to 53.4%. Among the management strategies, the use of resistant genotypes is an ideal tool for disease management, which led to the present research whose objective was to evaluate the resistance of cowpea genotypes (Vigna unguiculata (L.) Walp) to Sclerotium wilt under net house conditions. The study consisted of two experiments, the first one determined the resistance of 12 genotypes to two Sclerotium spp. strains, this was established under a completely randomized design with 12x3 factorial arrangement, with a total of 36 treatments with 3 replications (each experimental unit consisted of 1 plant, for a total of 432 experimental units), the data collection was carried out every seven days for 35 days. Resistance was evaluated considering epidemiological variables PI (incubation period), PL (latency period), incidence and severity of the disease. In the second experiment, the phenological stage of cowpea most susceptible to the disease was determined, the materials were inoculated at four phenological stages of the crop cycle, established under a completely randomized design with a 12x4 factorial arrangement for a total of 48 treatments with 3 replications (each experimental unit was a bag with three plants for a total of 288 experimental units). Evaluations were carried out every seven days for 21 days after inoculation and the variables of response, incidence and severity of the disease were measured. Disease intensity index values were fitted to growth models, and cumulative disease progress curves over time were obtained and epidemiological parameters were calculated. Data were transformed into ranges and analyzed by nonparametric statistics, followed by a Duncan 5% test. The percentages of emergence, incidence, severity, intensity index, incubation period, and latency period showed differences depending on the strain, genotype, and inoculation time evaluated. Disease intensity index values were best fitted to the monomolecular model. The Monteria strain was the most aggressive; whereas, seven genotypes were classified as resistant, two tolerant and three susceptible to S. rolfsii. The interaction between genotype and phenological stage was significant at 5%, with the V0 stage (at planting) being the most susceptible to the disease, representing the critical period of infection. The results suggest that genotypes IT-86, Negro, Gurgueia and BRS-Jurua were more resistant and can be used as parents in breeding programs for the management of Sclerotium wilt.Publicación Acceso abierto Zonificación preliminar de amenazas por movimientos en masa en la cuenca alta del Río Sinú a través de la evaluación multicriterio en un entorno de sistemas de información geográfica – SIG(2023-02-27) Bernal Gutiérrez, Jean Carlos; Martínez López, MauricioEl presente estudio consiste en zonificar el grado de amenaza por movimientos en masa en la cuenca alta del río Sinú a escala 1:100.000, a través del método heurístico “Evaluación Espacial Multicriterio” (EEM), el cual responde a un propósito de información y planeación a niveles básicos e intermedios de zonificación y a escalas cartográficas no detalladas. Dicha EEM se basó en la jerarquía analítica y se llevó a cabo con ayuda de los sistemas de información geográfica – SIG. Para cumplir con el objetivo de este trabajo, se estudiaron características intrínsecas de la zona de estudio definidas como factores condicionantes, para categorizar la susceptibilidad a movimientos en masa en la cuenca, y así, en sinergia con un factor desencadenante que en este caso fue la precipitación, encontrar el nivel de amenaza a movimientos en masa en la cuenca alta del río Sinú. De este modo se definió la amenaza a movimientos en masa del año y para las temporalidades de época seca y lluviosa en la cuenca, sirviendo este análisis de temporalidades del factor desencadenante como comparativo que ayudaría a definir la influencia de una mayor precipitación respecto al grado de amenaza a movimientos en masa, encontrando así que para le época lluviosa la amenaza es mucho mayor, por lo que se concluye que las lluvias efectivamente inciden considerablemente en el nivel de amenaza del terreno a que se generen movimientos en masa. A nivel general, se encontró que la cuenca alta del río Sinú presenta una amenaza alta en la mayoría del terreno, presentando un cubrimiento del 41,31 % de toda el área.