Explore the vast range of titles available.

Fusarium wilt of banana caused by the soil-borne fungi Fusarium oxysporum f. sp. cubense, Tropical Race 4 (Foc TR4) (Syn. Fusarium odoratissimum), is a major threat to the global banana industry. Aiming to identify predisposing soil factors for Fusarium wilt of banana (FWB) TR4, the 23 physical and chemical soil properties were studied in three commercial banana farms in La Guajira, Colombia. Disturbed and undisturbed soil samples were collected from areas affected by the disease (affected plots) and disease-free areas (healthy plots). Five repetitions per farm were considered, with a total sample of n = 30. The data were analyzed using one-way analysis of variance (ANOVA). Subsequently, the debiased sparse partial correlation (DSPC) algorithm was applied. Organic matter (OM), pH, calcium (Ca), magnesium (Mg), zinc (Zn), and cation-exchange capacity on the exchange complex (ECEC), showed significant differences between the affected and healthy plots. In addition, the bulk density and saturated hydraulic conductivity (HC) were associated suggesting that physical attributes, such as soil compaction and poor drainage, create favorable conditions for FWB. According to the DSPC algorithm, the HC variable presented a grade of 5 and an intermediation of 14.67, which indicates that it has significant associations with BD, sand, porosity, ECEC, and OM and plays a critical role in the connection of other variables in the network and the differentiation of healthy and affected plots. These findings establish a baseline of information under field conditions in Colombia, which can be used to design soil management strategies to mitigate the detrimental effects of Foc TR4 by creating less favorable conditions for the pathogen.

The growing degree-days (GDD) provide an estimate of the accumulated thermal energy available for the development of a crop. The use of GDD allows measuring the heat requirements associated with the phenological stages of the crop, which allows in turn, to predict when a certain plant stage will occur knowing the daily temperatures. The aim of this study was to establish relationships among the effect of degree days (DD) to vegetative growth, first flowering and fructification (VG, Fl and Fr), on total yield per plant (TY/P) of eggplant grown under open-field conditions employing a randomized complete block design with 15 genotypes and four replicates. The results showed that: 1) The genotypes that initiated fruit production in less time required fewer GDD (892.14-1,077.71 °C) for this phenological phase, obtaining higher productivity. 2) The genotypes C035 and C040 had an average yield higher than the national average with values of 83.75 and 84.86 t ha-1, being identified as future varieties to be produced in the Caribbean region. 3) The Caribbean region is suitable for the establishment of the crop as there were no events with limiting temperatures for this species (higher than 35 °C and lower than 15 °C). 4) The principal component analysis showed associations among the variable YT/P with the genotypes C011, C042, and C015; meanwhile, C032, C025, and C028 were associated with the variables DD to VG, Fl, and Fr. These results would be useful in developing a model to estimate yield with DD.

El fenotipo es el efecto acumulativo del genotipo (G), del ambiente (A) y su interacción (G x A). El ambiente es el factor que afecta en mayor medida el fenotipo debido a que varía entre localidades, temporadas y estaciones del año, mientras que los efectos de los genotipos son constantes. El objetivo de este trabajo fue identificar genotipos de berenjena (Solanum melongena L.) altamente productivos y fenotípicamente estables, con frutos aceptables para los mercados de exportación y nacional, calificados, respectivamente, de primera y segunda categoría, a partir del análisis de estabilidad mediante el modelo AMMI y el índice de superioridad (Pi) de Lin y Binns. Para el efecto se utilizaron variables asociadas con rendimientos de 15 genotipos de berenjena evaluados en tres ambientes de la región Caribe de Colombia. Los resultados mostraron que: (1) El rendimiento de frutos de primera y segunda categoría fueron significativos (P < 0.001) para la interacción genotipo x ambiente, (2) los materiales Corpoica (C) C015, C027, C035, C036 y C049 lo fueron para el rendimiento de primera categoría y C014, C025, C032, C040 y C049 para el rendimiento de segunda categoría, ya que se ubicaron cerca al cero del CP1, por tanto contribuyen en menor medida a la interacción genotipo x ambiente y son los materiales con el comportamiento más estable; y (3) los genotipos más estables según el Pi para el rendimiento de primera categoría fueron el C006, C026, C027, C035 y C040; y para el de segunda categoría fueron C014, C035, C040, C042 y C049; los cuales, en su mayoría, coinciden con los genotipos más estables y de mayor rendimiento de acuerdo al análisis AMMI.

RESUMEN Mycosphaerella fijiensis M. Morelet, es uno de los agentes causales del “complejo Sigatoka”, el cual, es la enfermedad más destructiva en los cultivos de banano y plátano. En el presente trabajo, se modeló espacialmente mediante técnicas geoestatísticas, la hoja más joven manchada (HMJM), como variable biológica indicadora del estado de severidad de la enfermedad en la plantación, con el objetivo de determinar su estructura y categoría de dependencia espacial. La HMJM se evaluó en las semanas 43, 45, 46 y 47 de 2005, em 71 plantas de banano cv. Gran Enano con emisión reciente de su inflorescencia, ubicadas en las intersecciones de una malla irregular, con una distancia mínima entre pares de plantas de 21 m y una distancia máxima de 1077 m, en una finca bananera situada en el municipio de Carepa (Antioquia), zona de vida bosque húmedo tropical (bh-T). La variable presentó un comportamiento anisotrópico para las semanas 45, 46 y 47; éste, se describió a partir de un modelo gaussiano en cada una de las semanas, con un rango de dependencia espacial decreciente de 673.25, 345.53 y 296.36 m, respectivamente, el cual diverge de los modelos reportados en otras investigaciones en patosistemas similares. Los modelos que se ajustaron para las semanas 45 y 47, evidenciaron fuerte dependencia espacial; el modelo de la semana 46, moderada dependencia espacial y el modelo de la semana 43, nula dependencia espacial. RESUMO Mycosphaerella fijiensis M. Moleret é um dos agentes causadores do “complexo Sigatoka”, o qual é a doença mais destrutiva na cultura da banana e do plátano. No presente trabalho, foi modelada espacialmente, mediante técnicas geoestadisticas, a folha mais jovem manchada (FMJM) como a variável biológica indicadora da severidade da doença na cultura, com o objetivo de determinar a sua estrutura e categoria de dependência espacial. A FMJM foi avaliada nas semanas 43, 45, 46 e 47 de 2005, sobre 71 plantas de bananeira cultivar Gran Enano com emissão recente da inflorescência. Demarcou-se, no campo, uma malha irregular, com uma distância mínima entre pares de plantas de 21 m e uma distância máxima de 1077 m, numa fazenda, localizada no Município de Carepa (Antioquia), região de floresta úmida tropical (fu-T). A variável apresentou um comportamento anisotrópico para as semanas 45, 46 e 47, foi descrito a partir de um modelo Gaussiano em cada uma das semanas, com uma gama de dependência espacial decrescente de 673.25, 345.53 y 296.36 m, respectivamente, o que diverge dos modelos reportados em outras pesquisas, em patossistemas similares. Os modelos que se ajustaram para as semanas 45 e 47, mostraram forte dependência espacial; o modelo da semana 46, moderada dependência espacial e o modelo da semana 43, sem dependência espacial.

Fusarium wilt of banana caused by the soil-borne fungi Fusarium oxysporum f. sp. cubense, Tropical Race 4 (Foc TR4) (Syn. Fusarium odoratissimum), is a major threat to the global banana industry. Aiming to identify predisposing soil factors for Fusarium wilt of banana (FWB) TR4, the 23 physical and chemical soil properties were studied in three commercial banana farms in La Guajira, Colombia. Disturbed and undisturbed soil samples were collected from areas affected by the disease (affected plots) and disease-free areas (healthy plots). Five repetitions per farm were considered, with a total sample of n = 30. The data were analyzed using one-way analysis of variance (ANOVA). Subsequently, the debiased sparse partial correlation (DSPC) algorithm was applied. Organic matter (OM), pH, calcium (Ca), magnesium (Mg), zinc (Zn), and cation-exchange capacity on the exchange complex (ECEC), showed significant differences between the affected and healthy plots. In addition, the bulk density and saturated hydraulic conductivity (HC) were associated suggesting that physical attributes, such as soil compaction and poor drainage, create favorable conditions for FWB. According to the DSPC algorithm, the HC variable presented a grade of 5 and an intermediation of 14.67, which indicates that it has significant associations with BD, sand, porosity, ECEC, and OM and plays a critical role in the connection of other variables in the network and the differentiation of healthy and affected plots. These findings establish a baseline of information under field conditions in Colombia, which can be used to design soil management strategies to mitigate the detrimental effects of Foc TR4 by creating less favorable conditions for the pathogen.

Los grados días de desarrollo (GDD) proporcionan una estimación de la energía térmica acumulada disponible para el desarrollo de un cultivo. El uso de los GDD permite medir los requerimientos de calor asociados a las etapas fenológicas del cultivo, lo que a su vez permite predecir cuándo ocurrirá una determinada etapa de la planta conociendo las temperaturas diarias. Este estudio tuvo como objetivo determinar las relaciones entre el efecto de los grados días (GD) hasta el crecimiento vegetativo, la primera floración y fructificación (CV, Fl y Fr) sobre el rendimiento total por planta (RT/P) de berenjena cultivada en campo abierto bajo un diseño de bloques completos al azar con 15 genotipos y cuatro repeticiones. Los resultados mostraron que: 1) Los genotipos que inician producción de frutos en menor tiempo requieren menos grados días (892,14-1.077,71 °C) para está fase fenológica, obteniendo una mayor producción. 2) Los genotipos C035 y C040 tuvieron un rendimiento promedio superior al promedio nacional con valores de 83,75 y 84,86 t ha-1, identificándose como futuras variedades a producir en la región del Caribe. 3) La región Caribe es apta para el establecimiento del cultivo, debido a que no hubo eventos limitantes de temperatura para la especie (temperaturas mayores a 35 °C y menores a 15 °C). 4) El análisis de componentes principales mostro asociación entre los genotipos C011, C042 y C015 con las variables RT/P, y los genotipos C011, C025 y C028 con los GD a CV, Fl y Fr. Estos resultados serían útiles para desarrollar un modelo para estimar el rendimiento con base en los GD. The growing degree-days (GDD) provide an estimate of the accumulated thermal energy available for the development of a crop. The use of GDD allows measuring the heat requirements associated with the phenological stages of the crop, which allows in turn, to predict when a certain plant stage will occur knowing the daily temperatures. The aim of this study was to establish relationships among the effect of degree days (DD) to vegetative growth, first flowering and fructification (VG, Fl and Fr), on total yield per plant (TY/P) of eggplant grown under open-field conditions employing a randomized complete block design with 15 genotypes and four replicates. The results showed that: 1) The genotypes that initiated fruit production in less time required fewer GDD (892.14-1,077.71 °C) for this phenological phase, obtaining higher productivity. 2) The genotypes C035 and C040 had an average yield higher than the national average with values of 83.75 and 84.86 t ha-1, being identified as future varieties to be produced in the Caribbean region. 3) The Caribbean region is suitable for the establishment of the crop as there were no events with limiting temperatures for this species (higher than 35 °C and lower than 15 °C). 4) The principal component analysis showed associations among the variable YT/P with the genotypes C011, C042, and C015; meanwhile, C032, C025, and C028 were associated with the variables DD to VG, Fl, and Fr. These results would be useful in developing a model to estimate yield with DD.