Nitrogen dynamics in field grown comice pears

Tesis para obtener el grado de Doctor of Philosophy (Ph.D.), de la Oregon State University, en mayo de 1990The dynamics of N was studied in field grown Comice/Provence quince BA29 pears in Medford, Oregon. Total tree biomass, N content, and ¹⁵N evaluations suggest that young pears require little N (48 kg N ha⁻¹ yr⁻¹). About 45% of total tree N present in dormant trees was remobilized into new growth the following season. Main storage organs were roots, frame and one-year wood. Before leaf fall, peripheral, medium and interior canopy leaves exported to storage tissues 71, 61 and 52% of their total N, respectively. The export of N was influenced more by leaf position in the canopy than the nutritional status of the tree. Shoot and fruit growth were dependent on newly absorbed N. A heavy crop load caused more stored N to be diverted into fruits at the expense of other tree components. Early spring application of N resulted in a buildup of tree reserves for developing buds, but produced excessive growth and resulted in fruits with undesirable high concentration of N. From harvest until leaf fall very little N was partitioned into the aerial portion of the tree. In order to increase sustantially N reserves in the aboveground structure of the tree, and avoid excessive shoot growth and high N fruits, N should be applied 3-6 weeks before harvest. When N was applied at or after harvest but before leaf fall, roots were primarily the site of N storage. At that time 5 or 10% postharvest urea spray was the only effective way to obtain labelled N in flower buds. Early spring growth normally depended on N reserves. However when temperature around bloom was warmer than the long term average newly absorbed N was translocated to the flowers. During the first 3-4 weeks after bloom newly absorbed N was partitioned to spur leaves while shoot leaves were more dependent on stored N. Once spur leaves reached full expansion N was diverted into shoot leaves and fruits. Fruits from the same tree varied considerable in N concentration especially when fertilizer N was applied after bloom. Trees with high N status discriminated in the allocation of N to fruit in different canopy positions but trees with low N status did not. Large number of fruits in any specific location lessened N concentrations. The location of the fruit in the canopy only partially explains N variability. Similar sized fruits only a few centimeters apart may have a two fold concentration range.EEA Alto ValleFil: Sanchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin

Tree Nitrogen Status and Leaf Canopy Position Influence Postharvest Nitrogen Accumulation and Efflux from Pear Leaves

`Cornice' pear trees (Pyrus communis L.) were fertilized with ammonium nitrate depleted in “N in Spring 1987 and 1988. In Aug., Oct., and Nov. 1988, midleaves on current season shoots were sampled at three positions from the periphery to the center of the canopy. Total N/cm' of leaf area remained almost constant through October, even though percent N concentration declined as specific leaf weight (SLW) increased. Furthermore, there was no substantial net change in either labeled or unlabeled N in either treatment until senescence began in October. Peripheral leaves contained higher levels of both reserve and newly acquired N than did less-exposed leaves. Despite large differences in N/cm2 for October samples, by November leaves from both high (HN) and low N (LN) trees exported similar percentages of their total N. The average N export to storage tissues irrespective of tree N status was 71%, 61%, and 52% for peripheral, medium, and interior leaves, respectively. The export of N was influenced more by the leaf position in the plant canopy than the nutritional status of the tree.EEA Alto ValleFil: Sanchez, Enrique Eduardo. Oregon State University. Department of Horticulture; Estados Unidos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Righetti, Timothy L. Oregon State University. Department of Horticulture; Estados Unido

Programa Nacional Frutales. Superficie ocupada por plantaciones frutales en el país y cambios en su estructura productiva

El objetivo de esta publicación ha sido actualizar la superficie plantada con Frutales en el país y dar visibilidad a aquellas regiones líderes y a sus cadenas de valor más representativas. La megacadena es generadora de divisas y de empleo en las llamadas economías regionales. Sin embargo, en los últimos años, la actividad en la mayoría de las cadenas ha sufrido cambios importantes y no deseados. En líneas generales, si se compara la superficie actual con la ocupada a fines de la década 90 o inicios del 2000, se puede observar cambios regresivos principalmente en los frutales de pepita, carozo, arándano, banano, pomelo, uva de mesa, e incremento en las plantaciones de frutos secos, kiwi, limón y cerezo en la Patagonia. Los datos relevados son producto de datos censales, publicaciones y aportes por parte de informantes calificados de la Institución.EEA BalcarceFil: Sánchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Importancia de la genética como ciencia en relación a la pandemia de COVID-19: Importance of genetics as a science in relation to the COVID-19 pandemic

The current COVID-19 pandemic has become a major global public health problem with almost one and a half million cases and tens of thousands of deaths until now. Genetics is playing a leading role in the identification, management and treatment of diseases. This article details the importance of genetics as a science to face the global threat of COVID-19, from different approaches. The contributions that genetics have had and will continue to have in the identification of the new SARS-CoV-2 virus, in the development of new diagnostic techniques, in the prevention of infections and development of severe symptoms, as well as in the design of vaccines and in the proposal and evaluation of treatments for COVID-19.La actual pandemia de COVID-19 se ha convertido en un grave problema de salud pública mundial, contándose casi un millón y medio de casos y decenas de miles de muertes a la fecha. La genética por su parte está teniendo un papel protagónico en la identificación, manejo y tratamiento de enfermedades. En el presente artículo se detalla sobre la importancia de la genética como ciencia para afrontar la amenaza global de la COVID-19, desde diferentes enfoques. Se resaltan los aportes que ha tenido y seguirá teniendo la genética en la identificación del nuevo virus SARS- CoV-2, en el desarrollo de nuevas técnicas diagnósticas, en la prevención de contagios y del desarrollo de cuadros graves, así como en el diseño de vacunas y en la propuesta y evaluación de tratamientos para la COVID-19

Acciones gubernamentales que han afectado el desarrollo e implementación de la Biotecnología en Salud en el Perú, periodo 2016 – 2021

Identifica acciones gubernamentales relacionadas al desarrollo e implementación de la biotecnología en salud en Perú entre el 28 de julio de 2016 y el 28 de julio de 2021. Se identificó un creciente interés gubernamental en impulsar el desarrollo e implementación de la biotecnología en salud en Perú a través de políticas, mayor financiamiento y una mayor representación de la comunidad científica en el periodo de estudio. Sin embargo, el estadio de la biotecnología en salud, así como del sistema de ciencia, tecnología e innovación (CTI) sigue presentando indicadores por debajo del promedio regional y global. En particular, se halló que mientras que la inversión en CTI por parte del gobierno central, a pesar de la tendencia ascendente, se mantuvo por debajo del 0.02% del PBI peruano, cuando el promedio de Latinoamérica y el Caribe era ya de 0.67% del PBI para el 2018, mientras que el promedio mundial ascendía a 2.2% del PBI en ese mismo año. La presente tesis compila indicadores relevantes del manejo de la CTI y, específicamente, de la biotecnología en salud en Perú, emitiendo recomendaciones para su mejora y con ello, eventualmente, ayudar a alcanzar mayores niveles de bienestar en la nación.Proyecto FONDECYT con Contrato N° 09-2019-FONDECYT-BM-INC.INV: “Implementación de una Plataforma de Referencia para el Control y Vigilancia de Enfermedades Parasitarias de Alto Impacto en el Perú y Desarrollo de un Dispositivo Multidiagnóstico en Puntos de Atención al Paciente” ganado por el Instituto de Enfermedades Tropicales de la Universidad Nacional Toribio Rodríguez de Mendoza de Amazona

Timing of nitrogen fertilization influences color and anthocyanin content of apple (Malus domestica Borkh. cv ‘Royal Gala’) fruits

Different timings and methods of N application modify N dynamics in the plant and could have differential effects on fruit color. To evaluate this possibility, an experiment was conducted during three seasons in a ‘Royal Gala’/EM9 apple orchard. The treatments were: (a) soil N after harvest; (b) foliar N after harvest; and (c) soil N in spring. No nitrogen was applied to the control. HUE angle, lightness, percentage of coverage color, and anthocyanin concentration were determined in the fruit skin. Among the treatments that received fertilization, the postharvest treatments resulted in fruits with darker colorations, higher percentages of coverage color, and higher concentration of anthocyanins. These could be related, at least partly, to lower values of light interception by the canopy, in comparison to the spring treatment. Our results suggest that the negative effects of N on fruit coloration can be mitigated by differing N application to the postharvest period.EEA Alto ValleFil: De Angelis, Verónica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Sanchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Tognetti, Jorge Alberto. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Laboratorio de Fisiología Vegetal; Argentin

Nutrición mineral de frutales de clima templado

La Nutrición Mineral es una de las tantas prácticas culturales que contribuye a obtener buenos rendimientos y óptima calidad de fruta. Los primeros capítulos del libro, introducen al lector en aspectos básicos de conocimiento, tanto de suelos y su manejo, como de la fisiología de la nutrición, conocimientos que resultan imprescindibles para poder diagramar un correcto manejo nutricional de los frutales de clima templado. Seguidamente se abordan capítulos específicos que tratan el diagnóstico nutricional, el rol y manejo de los macro y micronutrientes y de la práctica de la fertilización convencional, foliar y por fertirriego. De lectura sencilla, la obra está dirigida a profesionales, estudiantes avanzados y productores, con el fin de aportar a la mejora de la sostenibilidad económica, ambiental y social del sector.EEA Alto ValleFil: Sánchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Curetti, Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin

Management of Nitrogen and Calcium in Pear Trees for Enhancement of Fruit Resistance to Postharvest Decay

Management of pear (Pyrus communis L.) trees for low N and high Ca content in the fruit reduced the severity of postharvest fungal decay. Application of N fertilizer 3 weeks before harvest supplied N for tree reserves and for flowers the following spring without increasing fruit N. Calcium chloride sprays during the growing season increased fruit Ca content. Nitrogen and Ca management appear to be additive factors in decay reduction. Fruit density and position in the tree canopy influenced their response to N fertilization. Nitrogen: Ca ratios were lower in fruit from the east quadrant and bottom third of trees and from the distal portion of branches. High fruit density was associated with low N: Ca ratios. Nutritional manipulations appear to be compatible with other methods of postharvest decay control.EEA Alto ValleFil: Sugar, David. Oregon State University. Southern Oregon Experiment Station; Estados UnidosFil: Righetti, Timothy L. Oregon State University. Department of Horticulture; Estados UnidosFil: Sanchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Khemira, Habib. Oregon State University. Department of Horticulture; Estados Unido

Efectos de la carga frutal y del ambiente lumínico en ciruelo D’Agen (Prunus domestica L.)

En Mendoza, los productores de ciruelo europeo no realizan raleo de frutos. La alta carga afecta directamente la calidad de la fruta, como así también puede comprometer la siguiente floración. La falta de poda invernal provoca un progresivo sombreado del interior de la copa, en donde se observa madera improductiva. El objetivo del presente estudio fue evaluar los efectos de la carga frutal y de la radiación lumínica sobre la eficiencia productiva, la calidad de los frutos y el retorno de floración. En un huerto comercial de ciruelo europeo cv. D’Agen sobre pie 'Marianna 2624', en San Rafael, Mendoza, se ajustó la carga frutal en primavera a dos niveles (9 y 18 frutos . cm-2 de área de la sección transversal de cada rama primaria, ASTR), y en la mitad de las plantas se atenuó la radiación incidente en un 54% mediante malla plástica negra. El sombreado artificial no afectó la eficiencia productiva, mientras que la reducción de la carga frutal la disminuyó, evidenciando una compensación insuficiente mediante el incremento en el peso medio de los frutos. Las plantas no sombreadas y con baja carga frutal tuvieron frutos con mayor porcentaje de sólidos solubles. En la temporada siguiente, la densidad de frutos resultó similar en ambos niveles de carga frutal, siendo mayor el retorno de floración y menor el porcentaje de cuaje cuando la carga frutal previa fue baja.In Mendoza, prune growers do not make fruit thinning; consequently fruit quality under heavy crop loads is lowered. In addition the following blooming might be negatively affected. Moreover, the lack of winter pruning increases shading at the inner part of the canopy, where appears unproductive wood. The aim of this study was to assess the effects of crop load and light intensity on yield efficiency, fruit quality and return bloom. The trial site was a commercial orchard with prunes cv. D’Agen grafted on 'Marianna 2624’ rootstock, at San Rafael, Mendoza. The crop load was fitted at two levels (9 and 18 fruits . cm-2 of main branch cross sectional area), where half of the plants were shaded with black plastic cloth, lowering the light intensity by 54%. The artificial shading did not affect the yield efficiency, while the low crop load decreased it, showing an insufficient compensation through the increase in fruit mean fresh weight. Non-shaded and low crop load plants had the highest soluble solids percent in fruits. At the following season, fruit density was similar for both crop loads, with a greater return bloom and lower fruit set when the prior crop load was low.EEA JunínFil: Chaar, Javier Emilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Junín; ArgentinaFil: Sanchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin

Phishing websites detection using a novel multipurpose dataset and web technologies features

[EN] Phishing attacks are one of the most challenging social engineering cyberattacks due to the large amount of entities involved in online transactions and services. In these attacks, criminals deceive users to hijack their credentials or sensitive data through a login form which replicates the original website and submits the data to a malicious server. Many anti-phishing techniques have been developed in recent years, using different resource such as the URL and HTML code from legitimate index websites and phishing ones. These techniques have some limitations when predicting legitimate login websites, since, usually, no login forms are present in the legitimate class used for training the proposed model. Hence, in this work we present a methodology for phishing website detection in real scenarios, which uses URL, HTML, and web technology features. Since there is not any updated and multipurpose dataset for this task, we crafted the Phishing Index Login Websites Dataset (PILWD), an offline phishing dataset composed of 134,000 verified samples, that offers to researchers a wide variety of data to test and compare their approaches. Since approximately three-quarters of collected phishing samples request the introduction of credentials, we decided to crawl legitimate login websites to match the phishing standpoint. The developed approach is independent of third party services and the method relies on a new set of features used for the very first time in this problem, some of them extracted from the web technologies used by the on each specific website. Experimental results show that phishing websites can be detected with 97.95% accuracy using a LightGBM classifier and the complete set of the 54 features selected, when it was evaluated on PILWD dataset.SIINCIBEUniversidad de Leó