9 research outputs found
Comparison of Lures Loaded with Codlemone and Pear Ester for Capturing Codling Moths, Cydia pomonella, in Apple and Pear Orchards using Mating Disruption
Studies were conducted in apple, Malus domestica Borkhausen and pear, Pyrus communis L. (Rosales: Rosaceae), orchards to evaluate the attractiveness of grey halobutyl septa loaded with 1 (L2) and 10 (Mega) mg of codlemone, 8E, 10E-dodecadien-1-ol, 3 mg of pear ester, ethyl (E,Z)-2,4-decadienoate (DA2313), and 3 mg of pear ester plus 3 mg of codlemone (Combo) to adult codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). All studies were conducted in orchards treated with pheromone mating disruption. All four lures were tested on diamond-shaped sticky traps placed in 60 plots of apple and 40 plots of pears in 2003/04, and in 62 plots of apples and 30 of pears in 2004–05. Combo lures attracted significantly more moths (males + females) than all the others in both years. Comparisons among flights showed significant differences mainly for flight 1 and 2, but not always for flight 3. Mega lures provided no significant improvement compared with L2 lures during both seasons regarding the total number of moths. Combo and DA2313 lures attracted fewer females than males during the whole season. For most sample dates, more virgin than mated females were attracted to Combo lures, except during the third flight, and the overall ratio was 60:40, although the difference was not statistically significant. We conclude that the Combo lures are better indicators of codling moth activity in pheromone treated orchards, regardless of pest population level, when compared with similar lures containing codlemone or pear ester alone
The Maunder minimum (1645-1715) was indeed a grand minimum: a reassessment of multiple datasets
Aims.
Although the time of the Maunder minimum (1645–1715) is widely known as a period of extremely low solar activity, it is still being debated whether solar activity during that period might have been moderate or even higher than the current solar cycle (number 24). We have revisited all existing evidence and datasets, both direct and indirect, to assess the level of solar activity during the Maunder minimum.
Methods.
We discuss the East Asian naked-eye sunspot observations, the telescopic solar observations, the fraction of sunspot active days, the latitudinal extent of sunspot positions, auroral sightings at high latitudes, cosmogenic radionuclide data as well as solar eclipse observations for that period. We also consider peculiar features of the Sun (very strong hemispheric asymmetry of the sunspot location, unusual differential rotation and the lack of the K-corona) that imply a special mode of solar activity during the Maunder minimum.
Results.
The level of solar activity during the Maunder minimum is reassessed on the basis of all available datasets.
Conclusions.
We conclude that solar activity was indeed at an exceptionally low level during the Maunder minimum. Although the exact level is still unclear, it was definitely lower than during the Dalton minimum of around 1800 and significantly below that of the current solar cycle #24. Claims of a moderate-to-high level of solar activity during the Maunder minimum are rejected with a high confidence level
Revisión. Viticultura de precisión. Líneas de investigación, retos y oportunidades del manejo sitio-específico en viña
Precision Viticulture (PV) is a concept that is beginning to have an impact on the wine-growing sector. Its practical implementation is dependant on various technological developments: crop sensors and yield monitors, local and remote sensors, Global Positioning Systems (GPS), VRA (Variable-Rate Application) equipment and machinery, Geographic Information Systems (GIS) and systems for data analysis and interpretation. This paper reviews a number of research lines related to PV. These areas of research have focused on four very specific fields: 1) quantification and evaluation of within-field variability, 2) delineation of zones of differential treatment at parcel level, based on the analysis and interpretation of this variability, 3) development of Variable-Rate Technologies (VRT) and, finally, 4) evaluation of the opportunities for site-specific vineyard management. Research in these fields should allow winegrowers and enologists to know and understand why yield variability exists within the same parcel, what the causes of this variability are, how the yield and its quality are interrelated and, if spatial variability exists, whether site-specific vineyard management is justifiable on a technical and economic basis.La Viticultura de Precisión (VP) es un concepto que empieza a tener un cierto impacto en el sector vitivinícola. Su implementación práctica está ligada al desarrollo de cierta tecnología: sensores y monitores de cosecha, sensores locales y remotos, Sistemas de Posicionamiento Global (SPG), equipos y maquinaria de aplicación variable, Sistemas de Información Geográfica (SIG) y sistemas para el análisis y la interpretación de la información. En este trabajo se ha llevado a cabo una revisión de las diferentes líneas de investigación relacionadas con la VP. Dichas áreas de investigación se han centrado en cuatro ámbitos muy concretos: 1) cuantificación y evaluación de la variabilidad intraparcelaria, 2) delimitación a nivel de parcela de zonas de tratamiento diferencial, en base al análisis y la interpretación de dicha variabilidad, 3) desarrollo de tecnologías para la actuación variable en campo (variable-rate technologies, VRT) y, finalmente, 4) evaluación de la oportunidad del manejo sitio-específico en viticultura. La investigación en estos ámbitos debe permitir a viticultores y enólogos conocer y comprender por qué la cosecha varía dentro de una misma parcela, cúales son las causas de dicha variación, cómo están interrelacionadas la cosecha y su calidad y, ante la existencia de variabilidad espacial, si está justificado técnica y económicamente el manejo diferencial de los viñedos
Análisis cluster de mapas de vendimia para la delimitación de zonas de manejo diferencial
Zonal management in vineyards requires the prior delineation of stable yield zones within the parcel. Among the different methodologies used for zone delineation, cluster analysis of yield data from several years is one of the possibilities cited in scientific literature. However, there exist reasonable doubts concerning the cluster algorithm to be used and the number of zones that have to be delineated within a field. In this paper two different cluster algorithms have been compared (k-means and fuzzy c-means) using the grape yield data corresponding to three successive years (2002, 2003 and 2004), for a ‘Pinot Noir’ vineyard parcel. Final choice of the most recommendable algorithm has been linked to obtaining a stable pattern of spatial yield distribution and to allowing for the delineation of compact and average sized areas. The general recommendation is to use reclassified maps of two clusters or yield classes (low yield zone and high yield zone) and, consequently, the site-specific vineyard management should be based on the prior delineation of just two different zones or sub-parcels. The two tested algorithms are good options for this purpose. However, the fuzzy c-means algorithm allows for a better zoning of the parcel, forming more compact areas and with more equilibrated zonal differences over time.El manejo zonal en viña requiere la delimitación previa de zonas estables de cosecha dentro de la parcela. Entre los diferentes métodos de zonificación existentes, el análisis cluster de los datos de cosecha de diferentes años es una de las posibilidades que han sido citadas en la literatura científica. Sin embargo, existen dudas razonables en relación al algoritmo que debe ser utilizado y al número de zonas que deben delimitarse dentro de la parcela. En este artículo se comparan dos algoritmos diferentes de clasificación (algoritmo de k-medias y algoritmo difuso de c-medias), a partir de los datos de cosecha (mapas de cosecha) correspondientes a tres años sucesivos de vendimia (2002, 2003 y 2004) en una parcela de uva ‘Pinot Noir’. La elección final del método (algoritmo) ha estado vinculada a la obtención de un patrón de cosecha estable en el tiempo y a la delimitación dentro de la parcela de zonas compactas y de cierto tamaño. La recomendación general es la utilización de mapas reclasificados en dos clases de cosecha (zona de cosecha baja y zona de cosecha alta) y, en consecuencia, el manejo sitio-específico en viña debería estar basado en la delimitación previa de únicamente dos zonas diferentes o subparcelas. Los dos algoritmos evaluados son una buena opción para este propósito. Con todo, el algoritmo difuso de c-medias permite una mejor zonificación de la parcela, formando áreas que, siendo más compactas en superficie, mantienen asimismo mejor equilibradas las diferencias zonales a lo largo del tiempo