La seca de encinas y alcornoques en Andalucía : decaimiento y enfermedad

El decaimiento forestal es una enfermedad de etiología compleja, resultado de la acción de un número variable de factores bióticos y abióticos que causan un deterioro gradual y general de los árboles afectados, hasta su muerte. Los factores implicados en el decaimiento de los Quercus en Andalucía son factores predisponentes de tipo selvícola, alteraciones climáticas como factor incitante, y plagas y enfermedades como factores contribuyentes. Entre las enfermedades implicadas en Seca de los Quercus destacan, por orden de importancia, la podredumbre radical causada por Phytophthora cinnamomi, los chancros de tronco y ramas causados por Botryosphaeria spp. y el chancro carbonoso causado por Biscogniauxia mediterranea. No obstante, las dos primeras enfermedades tienen una especial incidencia en distintas zonas de Andalucía de forma independiente, no asociadas al decaimiento. En el presente artículo se exponen las medidas de control disponibles contra estas enfermedades de los Quercus y se plantea la necesidad de disponer de un diagnóstico preciso en cada caso para abordar dicho control con garantías, ya que no cabe encontrar soluciones únicas que resulten eficaces con independencia de la naturaleza del problema._____________________________________The forestry decline is a complex disease, as a result of the action of a changeable number of biotic and abiotic factors that cause a gradual and general deterioration of the affected trees, until their death. The factors involved in the Quercus decline in Andalusia are predisposing factors like silvic, climatic alterations as inciting factor, and insect pest and diseases as contributing factors. Between the diseases involved in oak decline stand out, in order of importance, the root roting caused by Phytophthora cinnamomi, the chancres of trunk and branches caused by Botryosphaeria spp. and the charcoal canker caused by Biscogniauxia mediterranea. Nevertheless, the first two diseases have a special effect on different zones of Andalusia in different ways, not associated with the decay. In this article we expose the available tools of disease control. We emphasizes the need of having a precise diagnosis in every case to approach the control with guarantees, since there is no chance of finding only one efficient solution regardless of the nature of the problem

Distribución optimizada de volúmenes limitados de agua de riego y su efecto sobre el rendimiento y la calidad de la cebada cervecera

En Castilla-La Mancha (C-LM), la cebada es un cultivo con bajas necesidades de agua de riego (lámina neta, In=2.500 m3ha-1) y con una gran diferencia de rendimiento entre secano y regadío. Sin embargo, por la escasez de recursos hídricos, las dotaciones limitadas de agua, y el alto coste de la energía, los agricultores se están planteando aplicar riego deficitario a este cultivo. El objetivo de este trabajo es determinar, para las condiciones de C-LM, las estrategias de riego deficitario controlado que, con volúmenes limitados de agua de riego, maximizan el rendimiento de la cebada cervecera sin que la calidad del producto se vea afectada. Se han desarrollado ensayos de campo considerado 5 volúmenes de agua disponible (Ilimitada, 1 In, 0.9 In, 0.8 In, y 0.7 In), optimizando los calendarios de riegos combinando las metodologías “año meteorológico típico” (Tipical Meteorological Year,TMY) y “riego deficitario optimizado por etapas” (Optimized Regulated Deficit Irrigation, ORDI) con el modelo MOPECO. Se ha conseguido una buena distribución del agua disponible a lo largo de la campaña, sin alcanzar un estrés severo global en ninguna de las etapas de desarrollo, logrando un alto rendimiento sin decremento de la calidad, pese a desconocer las condiciones climáticas en las que se iba a desarrollar el cultivo. Los rendimientos obtenidos fueron similares a los estimados al inicio de la campaña y los parámetros de calidad medidos, excelentes en todos los tratamientos

Evaluación cuantitativa y cualitativa del cultivo de ajo morado bajo aplicación optimizada de volúmenes limitados de agua de riego

Castilla-La Mancha (C-LM) es una región de clima semiárido con escasez de recursos hídricos para el regadío. De las variedades de ajo utilizadas en la región, el Ajo Morado de las Pedroñeras presenta valores añadidos, tanto en aspectos económicos, como culturales y de calidad nutricional. Todo ello, unido al elevado coste de la energía asociada a los sistemas de riego presurizados, hace que muchos productores demanden estrategias para mejorar la eficiencia en el uso del agua y hacer más rentable el cultivo. El objetivo principal de este trabajo, es definir y validar estrategias de manejo del riego deficitario controlado, basadas en las metodologías año meteorológico típico (TMY) y del riego deficitario optimizado por etapas (ORDI) que distribuyan de manera óptima un volumen de agua de riego limitado durante las distintas etapas de desarrollo fenológico del Ajo Morado de Las Pedroñeras. Para ello, se ensayaron 5 tratamientos, uno sin déficit y cuatro con distintos volúmenes máximos de agua de riego disponible, correspondientes al 100 (T100), 90 (T90), 80 (T80) y 70% (T70) de las necesidades netas de riego del cultivo para las condiciones climáticas de un año meteorológico típico (TMY) intermedio en C-LM (fijadas en 3400 m3/ha). Como consecuencia de las condiciones climáticas del año del ensayo, los tratamientos no alcanzaron los niveles de déficit hídrico deseados. No se observaron diferencias significativas en cuanto a rendimiento y calidad para los tratamientos T90, T80 y T70

Assessment of fruit quality of grapefruit at postharvest influenced by reclaimed water and deficit irrigation

[SPA] El objetivo de la investigación fue evaluar los efectos a largo plazo del riego con agua regenerada (AR) y agua del trasvase (AT) y diferentes estrategias de riego (control, C, y riego deficitario controlado, RDC) sobre la calidad de pomelos durante su almacenamiento en frío. Los resultados mostraron que el riego con AR y, principalmente, el RDC incrementaron la cantidad de solidos solubles, mejorando así el índice de madurez. Sin embargo, el AR combinada con RDC disminuyó el nº de frutos de la categoría de mayor tamaño al final del almacenaje y AT-RDC presentó el menor contenido en zumo. [ENG] The aim of our research was to discover the effects of the long-term irrigation with saline reclaimed (RW) and transfer (TW) water and different irrigation strategies: control (C) and regulated deficit irrigation (RDI) on fruit quality of grapefruit during cold storage. Result showed sugar/acid ratio was mainly increased by RDI, but also by RW, due to an important increase in soluble solid content. However, RDI combined with RW, significantly decreased the number of fruits in the largest category 5 at the end of cold storage and TW-RDI showed lower values of juice content.This study was supported by two CICYT projects (AGL2010-17553 and AGL2013-49047-C2- 515 2-R) projects and SENECA–Excelencia Científica (19903/GERM/15)

Pressure effects on the magnetic properties of FeCuZr studied by x-ray magnetic circular dichroism: Evidence of weakening of ferromagnetism in FeCuZr alloys

The room temperature changes of the magnetic behavior under pressure of an invar alloy of nominal composition [Fe_(0.5)Cu_(0.5)]_(87)Zr_(13) (at. %) has been studied by K-edge x-ray magnetic circular dichroism (XMCD) and x-ray absorption near edge spectroscopy (XANES). The Curie temperature, as determined from low field magnetization measurements, is (255 ± 15) K. However XMCD shows a non negligible signal above this temperature. In addition, the XMCD signal decreases upon increasing pressure indicating a pressure-induced collapse of the magnetic moment. These results evidence the itinerant character of FeCuZr alloys as well as the occurrence of magnetovolume effects characterized by a strong dependence of the 3d band on the Fe-Fe nearest neighbor distances

Sub-arcsecond radio and optical observations of the likely counterpart to the gamma-ray source 2FGL J2056.7+4939

We have searched and reviewed all multi- wavelength data available for the region towards the gamma-ray source 2FGL J2056.7+4939 in order to con- strain its possible counterpart at lower energies. As a result, only a point-like optical/infrared source with flat-spectrum radio emission is found to be consistent with all X-ray and gamma-ray error circles. Its struc- ture is marginally resolved at radio wavelengths at the sub-arcsecond level. An extragalactic scenario appears to be the most likely interpretation for this object.Comment: 5 pages, 3 figures, 1 tabl

Changes in cannabinoid receptor binding and mRNA levels in several brain regions of aged rats

AbstractWe have recently found that cannabinoid receptor binding and gene expression markedly decreased in extrapyramidal structures of aged rats. The present study was designed to analyze the possible existence of similar aging-induced changes in cannabinoid receptor binding and gene expression in brain regions other than extrapyramidal areas, but that also contain a significant population of cannabinoid receptors, such as the cerebellum, hippocampal structures, limbic and hypothalamic nuclei, the cerebral cortex and others. To this end, we analyzed cannabinoid receptor binding, using autoradiography, and cannabinoid receptor mRNA levels, using in situ hybridization, in slide-mounted brain sections obtained from young (3 month old) and aged (>2 year old) rats. Results were as follows. In the cerebellum, aged rats exhibited a marked decrease in cannabinoid receptor binding in the molecular layer (−33.3%), although accompanied by no changes in mRNA levels in the granular layer. In the cerebral cortex, a small, although statistically significant, decrease in binding was found in the deep layer (VI) (−18.3%) of aged rats, whereas no changes were found in the superficial layer (I). As in the case of the cerebellum, mRNA levels did not change in the cerebral cortex layers (II–III and V–VI). The different regions of the Ammon’s horn of the hippocampus exhibited similar cannabinoid receptor binding levels in aged and young rats. Interestingly, mRNA levels decreased in aged rats to a small, but statistically significant, extent (CA1: −26.1%; CA2: −21.6%; CA3: −14.4%). This was also seen in another hippocampal structure, the dentate gyrus (−14.6%), although in this region binding levels increased in aged rats (+28.4%). Two hypothalamic structures, the arcuate nucleus and the ventromedial hypothalamic nucleus, exhibited decreased cannabinoid receptor binding in aged rats (−31.1% and −30.3%, respectively), but this was not seen in the medial preoptic area. This was accompanied by no changes in mRNA levels in the ventromedial hypothalamic nucleus. In the limbic structures, aged rats exhibited similar binding levels to young rats. This was seen in the nucleus accumbens, septum nuclei and basolateral amygdaloid nucleus. However, mRNA levels slightly decreased in the basolateral amygdaloid nucleus (−13.4%), whereas they were not altered in the septum nuclei. Finally, other brain structures, such as the central gray substance and the brainstem, exhibited similar binding levels in aged and young rats. However, it is important to note that mRNA levels increased significantly (+211.2%) in the brainstem of aged rats, an area where the levels of binding and mRNA were very low in young rats. This marked increase may be related to an increase in the presence of glial elements in this region, as revealed by the increase in the immunoreactivity for glial fibrillary acidic protein observed in the brainstem of aged rats as compared to young animals. In summary, senescence was associated with changes in cannabinoid receptors in the cerebellum, the cerebral cortex, limbic and hypothalamic structures, the hippocampus and other brain regions. However, the changes observed (i) were not as marked and relevant as those early reported in extrapyramidal areas, and (ii) exhibited regional differences that might be attributed to the different roles played by these receptors in each region. Of particular relevance by their magnitude were the aging-induced decrease in binding found in the cerebellum and the hypothalamus, and the increase in mRNA levels observed in the brainstem. The latter might be related to an increase in the presence of glial cells which might contain cannabinoid receptor mRNA

Temperature dependence of the magnetic properties in LaMnO_(3+δ)

Data are presented on the thermal dependence of the hysteretic properties of cationic vacancies including manganite samples of composition LaMnO_(3+δ)(δ=0.05 and 0.12). Our results evidence the presence in both samples of two magnetic phases having ferro- and antiferromagnetic orders, respectively. The temperature dependence of the coercivity and relaxational properties of the samples is closely linked to the connectivity of the magnetic moment bearing Mn^(3+)-Mn^(4+) ferromagnetic clusters that demagnetize independently in the case of the δ=0.05 sample and collectively in that of the δ=0.12 one, as evidenced from the activation volume results (delta=0.05) which yielded a size of the same order magnitude as that obtained in previous works for the Mn^(3+)-Mn^(4+) ferromagnetic cluster size