Classification with linear discriminant analysis of morphological variables in peach (Prunus persica L. Batsch) ‘Jarillo’ in the Santandereana Mountains, Colombia

Páginas 39-47.Durante el 2014 en la provincia de Pamplona, Colombia, se realizó un estudio sobre la variedad de duraznero Jarillo, con el fin de clasificar una serie de variables morfométricas distribuidos en tres fincas de diferenter altitud (Pamplona, 2.170 msnm; Chitagá, 1.870 msnm y Pamplonita, 1.670 msnm). Para el muestreo de árboles se utilizó el hipercubo latino condicional. En las hojas se midió el ancho por la longitud de limbos y el área del limbo usando el software ImageJ. En los frutos se midió el diámetro longitudinal sobre ecuatorial y los pesos secos. Se aplicó la técnica del análisis discriminante lineal, el cual se complementó con el diagrama de cajas por finca con los valores de la función discriminante para las muestras de diferentes grupos y se finalizó con la gráfica de dispersión de las dos mejores funciones discriminantes. Esta clasificación sugiere un manejo agronómico diferenciado entre Pamplonita y Chitagá, sobre todo en la cosecha, pues esta involucra el peso seco de los frutos. Existe un área común entre Pamplona y Pamplonita, lo cual puede atribuirse a que ambas se encuentran en la cuenca del Catatumbo. Los valores de largo por ancho del limbo y área del limbo fueron caracteres fuertemente discriminantes en este estudio, son susceptibles de variar debido a factores ambientales. El estudio concluyó que las fincas Chitagá y Pamplonita se discriminan claramente en lo que respecta a las variables medidas, alcanzando la función discriminante un 89,3% de separación en las variables.ABSTRACT: During 2014, in the province of Pamplona, Colombia, a study on the peach variety Jarillo was carried out in order to classify a series of morphometric variables in this crop, grown at three different altitudes (Pamplona, 2,170 m a.s.l., Chitaga, 1,870 m a.s.l., and Pamplonita, 1,670 m a.s.l). The conditional Latin hypercube sampling approach was used to select samples of the trees. In the leaves, the width was measured with the length of the limbs and the limbus area using the software ImageJ. In the fruits, the longitudinal r on the equatorial diameter and dry weight were measured. The linear discriminant analysis technique was applied, which was complemented with boxes diagram by farm with the values of the discriminant function for the samples of the different groups and ended with the scatter plot of the two best discriminant functions. This classification suggested different agronomic management plans for Pamplonita and Chitagá, especially for the harvest that involved the dry weight of the fruits. There is a common area between Pamplona and Pamplonita, which can be attributed to the fact that both are in the Catatumbo basin. The values of length and width of the limbus and limbus area were highly discriminating characteristics in this study and were susceptible to change because of environmental factors. The study concluded that the farms Chitagá and Pamplonita were clearly discriminated according to the measured variables, reaching discriminant function with 89.3% separation in the variables.Bibliografía: páginas 46-47.Artículo revisado por pares

RankspeQ: An R package platform for genotype characterization and performance-ranking based on MultispeQ measurements

With the new technologies in plant phenotyping, robust and reliable tools are still required to analyze large-scale and multivariate datasets. The RankspeQ is a novel R package developed to evaluate genotype performance and to support selection-driven decisions based on leaf traits and environment-related variables measured by the MultispeQ device. The presented software consists of 3 main functions: i) data cleaning, ii) computational trait- genotype ranking, and iii) comparison of accessions against grain yield or another crop trait. Optionally, the evaluation can be performed by alternative groups which can be defined by the user, such as genepools, families, among others. The software development as well as the data evaluation was made with datasets of Phaseolus spp. experiments. However, R code - with easy modifications - can be used on any other crop. This valuable tool helps to understand the hidden potential of MultispeQ equipment and - most - identify crop traits useful in genotype characterization in particular environments. The tool has direct potential for physiologists, breeders etc. as it identifies the best performing accessions. However, it also targets false positive results with low yield but high photosynthetic performance. We also propose to use a new efficiency index to calculate the ratio of incoming radiation for net photosynthesis in proportion to light dissipation processes. Further updates will include new algorithms (e.g. trait heritability), generalization to other species and a shiny interface to make the software user friendly

Influence of microbial consortia on the incidence of grey mold (Botrytis cinerea) in strawberry (Monterey variety)

Botrytis cinerea, el agente causal de la enfermedad del moho gris, es uno de los patógenos más destructivos del cultivo de fresa, tanto en el desarrollo vegetativo como en poscosecha. El control de este patógeno es complejo, debido a su agresividad y capacidad de atacar e infectar diversos tejidos de la planta y se basa, principalmente, en el control químico; sin embargo, el uso incorrecto de plaguicidas, principalmente por sobredosificación, provoca la presencia de trazas de estos agroquímicos en los frutos, así como la selección de resistencia del patógeno a los fungicidas, convirtiéndolo en un riesgo para la salud humana y el ambiente. El objetivo del estudio fue utilizar estrategias de regulación biológica, con la aplicación de consorcios microbianos, conformados por hongos micorrícicos, bacterias antagonistas y Trichoderma harzianum, como alternativa para el manejo del moho gris, en cultivos de fresa (variedad Monterey), en condiciones de campo. Los tratamientos T4 (hongos micorrízicos), T8 (hongos micorrízicos, bacterias antagonistas y T. harzianum) y T2 (T. harzianum) presentaron la menor incidencia del patógeno, con 2,6, 3,1 y 3,6 %, respectivamente, en comparación con las plantas control, con 16,6 %. La influencia de todos los tratamientos biológicos en la regulación de B. cinerea fue mayor respecto al control.Botrytis cinerea, the causal agent of grey mold disease, is one of the most destructive pathogens of strawberry crops, both in vegetative development and postharvest. The control of this pathogen is complex due to its aggressiveness and ability to attack and infect various plant tissues and is mainly based on chemical control; however, the incorrect use of pesticides, mainly due to overdosing, causes the presence of traces of these agrochemicals in the fruits, as well as the selection of pathogen resistance to fungicides, making it a risk to human health and the environment. The objective of the study was to use biological regulation strategies, with the application of microbial consortia made up of mycorrhizal fungi, antagonistic bacteria and Trichoderma harzianum, as an alternative for the management of grey mold in strawberry crops (Monterey variety) under field conditions. Treatments T4 (mycorrhizal fungi), T8 (mycorrhizal fungi, antagonistic bacteria and T. harzianum) and T2 (T. harzianum) presented the lowest incidence of the pathogen with 2.6, 3.1 and 3.6 %, respectively, compared to control plants with 16.6%. The influence of all biological treatments on the regulation of B. cinerea was greater than the controlIncluye referencias bibliográfica

Efecto de la coordenada representativa de la agregación en datos de conductividad eléctrica aparente y su relación con medidas de dependencia espacial

Estimating soil resources at a different scale on which observations are made is a major problem that continues to generate related research. An increase in scale means an increase in the variation of the parameter, and this can cause problems when interacting with non-linearity in a process or model. Changing the spatial resolution by adding or disaggregating data carries the risk of conflicting results. To demonstrate this fact, Apparent Electrical Conductivity data were taken with the EM38-MK2 sensor in a vertical position to the ground simultaneously with the two dipoles at two relative depths (0.75m and 1.5m), associated with the same coordinate. Spatial aggregation sizes were evaluated from a fishnet of 5m´5m to 70m´70m, with an arithmetic ratio of 5m. Representative coordinates were used to generate the matrix of spatial weights based on the: i) center of the grid, ii) mean value of the coordinates that spatially intercept each cell, and iii) value of the centroid of the points added by each cell. To analyze the spatial autocorrelation pattern, the Moran Montecarlo index was used for the residuals of the adjusted model. The results showed that as the size of the grid is increased, the univariate spatial dependence begins to decrease for all representative coordinates, with the coordinate of the center of the cell being the most affected. For a specific sensor depth, the use of the centroid coordinate and in aggregations that exceed 20m is recommended to maintain the spatial dependency structure that could be natural in this variable and convenient in spatial regression modeling processes.La estimación de los recursos del suelo a una escala diferente en las que se hacen las observaciones es un problema de importancia que sigue generando investigaciones relacionadas. Un aumento en la escala significa un aumento en la variación del parámetro, y esto puede causar problemas al interactuar con la no linealidad en un proceso o modelo. Cambiar la resolución espacial agregando o desagregando datos conlleva el riesgo de resultados contradictorios. Para demostrar este hecho se tomaron datos de Conductividad Eléctrica Aparente con el sensor EM38-MK2 en posición vertical al suelo de forma simultánea con los dos dipolos a dos profundidades relativas (0.75m y 1.5m), asociados a una misma coordenada. Se evaluaron tamaños de agregación espacial desde una rejilla de 5m´5m hasta 70m´70m, con razón aritmética de 5m. Se usaron coordenadas representativas para generar la matriz de pesos espaciales basada en el: i) centro de la grilla, ii) valor medio de las coordenadas que interceptan espacialmente cada celda, y iii) valor del centroide de los puntos agregados por cada celda. Para analizar el patrón de autocorrelación espacial se usó el índice de Moran Montecarlo para los residuales del modelo ajustado. Los resultados mostraron que a medida que se aumenta el tamaño de la rejilla, la dependencia espacial univariada comienza a disminuir para todas las coordenadas representativas, siendo la coordenada del centro de la celda la más afectada. Para una profundidad específica del sensor, se recomienda el uso de la coordenada del centroide y en agregaciones que superen los 20m para mantener la estructura de dependencia espacial que pudiera ser natural en esta variable y conveniente en procesos de modelado mediante regresión espacial

Growth of iJatropha curcas/i L. fertilized with nitrogen and potassium under conditions of dry tropical forest of Colombia

Due to the demand in biofuel, the plant species that are not eatable and do not compete with traditional crops in Colombia, such as Jatropha curcas L., have become an important option. To produce more knowledge on the growth of this species, the research was carried out with different amounts of N and K fertilizers applied during the first 435 days after sowing (das) under dry tropical forest conditions. With the highest N dose (150 kg ha-1), the largest leaf area index was obtained in all evaluation period. The highest net assimilation rate (NAR) values were seen in the treatment with 150 kg ha-1 of N at 75 das, 1.852 g m-2 d-1, with no differences presented among the treatments with fertilizer application. The highest absolute growth rate (AGR) was observed when 150 kg ha-1 of N+180 kg ha-1 of K2O were applied at the start of the reproductive phase (345 das), 24.5 g d-1. The specific leaf area (SLA) did not present a response to the treatments. The relative growth rate (RGR) reached zero value at 402 das for the plants without fertilizers. The accumulation of biomass in J. curcas was influenced by the fertilizers with N and K, presenting rapid initial vegetative growth (first 165 das) which decreased with the starting of the reproductive phase

Effect of aggregate size and superficial horizon differentiation on the friability index of soils cultivated with sugar cane: a multivariate approach

Soil friability is a physical property that provides valuable information for minimizing energy consumption during soil tillage and for preparing the edaphic medium for plant development. Its quantitative determination is generally carried out with aggregates obtained from soil blocks taken at fixed depths of profiles without considering the superficial horizons of the soil. The objective of the this study was to determine the effect of aggregate size and superficial horizon differentiation on the friability index (FI) of some soils cultivated with sugar cane in the Geographic Valley of the Cauca River (Colombia), using univariate (CVu) and multivariate (CVm) coefficients of variation. The FI was evaluated using a compression test with four aggregate-size ranges taken from the Ap and A1 superficial horizons of 182 sampling sites located on 18 sugar cane farms. Of the five types of studied soils (Inceptisols, Mollisols, Vertisols, Alfisols and Ultisols), 7,280 aggregates were collected that were air dried and subsequently dried in a low-temperature oven before determining the tensile strength (TS), which was in turn used to calculate the FI using the coefficient of variation method. This study found that the FI varied with the aggregate size and the soil depth (first two horizons). Only three of the four size ranges initially selected were relevant. The CVm proved to be very useful for the selection of a more relevant value from the confidence interval of the TS from the CVu method for friability and established that the lower limit value (FIi) of the TS CVu was the FI value that was closest to the multivariate measurement

Metabolic Profile of F1 Holstein × Zebu Lactating Dairy Cows Under Grazing Supplemented with Two Non-Protein Nitrogen Sources: Perfil metabólico de vacas lactantes F1 Holstein × Cebú a pastoreo suplementadas con dos fuentes de nitrógeno no proteico

Pastures dedicated to cattle production in Venezuela have a low crude protein concentration. One of the nutritional strategies to correct the forage protein deficit is using non-protein nitrogen in the diet. To evaluate the effect of two non-protein nitrogen sources on the metabolic profile of lactating dairy cows, 31 F1 Holstein × Zebu multiparous cows averaging 419 ± 46 kg body weight and 17.1 ± 3.3 kg milk·animal·d-1 were randomly assigned to two treatments for 91 days: 1) 59 g·animal-1·d-1 of urea and 2) 64 g·animal-1·d-1 of Optigen II® as slow-release urea (SRU). The animals were grazing (2.12 AU·ha-1) on Urochloa decumbens, U. humidicola, and U. brizantha (7.98-9.61 % CP) and supplied with 4 kg·animal·d-1 of concentrate (15 % CP), and 108, 60, and 108 g·animal·d-1 of mineral, molasses, and bypass fat, respectively. Glucose, total protein, albumin, cholesterol, urea, and β-hydroxybutyrate concentrations, aspartate aminotransferase, and gamma-glutamyl transferase activities were determined in blood serum samples every 28 days. ANOVA analyzed data in a completely randomized design with repeated measures. There were no differences among treatments in the parameters investigated; however, collecting time influenced all of them. No treatment × time interactions were found except for albumin concentration, higher in urea at day 0. The results indicate that under the conditions assayed in the present work, Optigen II® offers no advantage over urea concerning blood indicators of energy and protein metabolism and hepatic functionality in dairy cows.Los pastos dedicados a la producción ganadera en Venezuela tienen una baja concentración de proteína cruda. Una de las estrategias nutricionales para corregir el déficit de proteína del forraje es el uso de nitrógeno no proteico en la dieta. Con el objetivo de evaluar el efecto de dos fuentes nitrógeno no proteico sobre el perfil metabólico de vacas lecheras lactantes, 31 vacas F1 Holstein × Cebú multíparas con promedios de 419 ± 46 kg de peso vivo y 17,1 ± 3,3 kg leche/animal·d-1 se asignaron de forma aleatoria a dos tratamientos durante 91 días: 1) 59 g·animal·d-1 de urea y 2) 64 g·animal·d-1 de Optigen II® como fuente de urea de degradación lenta (UDL). Los animales pastaron (2,12 AU·ha-1) en Urochloa decumbens, U. humidicola y U. brizantha (7,98-9,61 % PC); adicionalmente, se les suministraba 4 kg·animal·d-1 de alimento concentrado (15 % PC) y 108, 60 y 108 g·animal·d-1 de mineral, melaza y grasa sobrepasante, respectivamente. Cada 28 días se determinó en suero sanguíneo las concentraciones de glucosa, proteínas totales, albúmina, colesterol, urea, β-hidroxibutirato, y la actividad de las enzimas aspartato aminotransferasa y gamma-glutamil transferasa. Los datos se analizaron mediante ANAVAR bajo un diseño completamente al azar con medidas repetidas. No hubo diferencias entre los tratamientos en las variables estudiadas; sin embargo, el tiempo de muestreo influyó en todas ellas. No se observaron interacciones tratamiento × tiempo, excepto para la concentración de albúmina, que fue mayor en urea en el día 0. Los resultados obtenidos indican que bajos las condiciones experimentales del presente trabajo, Optigen II® no ofrece ventajas adicionales sobre la urea con respecto a los indicadores sanguíneos del metabolismo energético y proteico y de la funcionalidad hepática en vacas lecheras.

Evaluation of the quality of the Voluntary Geographic Information for the road network in Bogotá D.C

The production of Voluntary Geographic Information has been growing considerably and continues to be an active area of research. However, the lack of knowledge about the quality of information generated on a voluntary and participatory basis raises challenges and questions about its use. In the review carried out for the Colombian case, no studies related to the subject were identified; consequently, this study is presented on the evaluation of the quality of this type of information on the road network of Bogotá with respect to completeness, positional accuracy and thematic accuracy. This evaluation was carried out by means of a semi-automatic process that uses a mobile buffer and the centroid of the roads to make the corresponding comparisons between two data sources. The results found reveal that the method used allowed to compare up to 85.0% of the data, and that the OpenStreetMap mesh has a completeness of 85.4%, over the entire area of Bogotá. A positional accuracy of 3.98 m and a thematic accuracy related to the percentage of error in the attributes: Road hierarchy, direction of flow and road naming of 35.8%, 15.0% and 34.6% respectively. The quality evaluated through completeness, positional and thematic accuracy in synergistic terms is deficient with respect to the minimum quality levels established in the standard data model, however, the evaluation for each of the attributes shows an acceptable quality in terms of completeness and thematic accuracy

Using phenomics to identify and integrate traits of interest for better-performing common beans: A validation study on an interspecific hybrid and its Acutifolii parents

Evaluations of interspecific hybrids are limited, as classical genebank accession descriptors are semi-subjective, have qualitative traits and show complications when evaluating intermediate accessions. However, descriptors can be quantified using recognized phenomic traits. This digitalization can identify phenomic traits which correspond to the percentage of parental descriptors remaining expressed/visible/measurable in the particular interspecific hybrid. In this study, a line of P. vulgaris, P. acutifolius and P. parvifolius accessions and their crosses were sown in the mesh house according to CIAT seed regeneration procedures