Recursos de colección

Repositorio Institucional de la Universidad de Cordoba :: Spain (54.829 recursos)

El repositorio recoge todo tipo de materiales digitales: artículos de revistas, comunicaciones a congresos, tesis doctorales, documentos de trabajo, materiales docentes y objetos de aprendizaje, así como los productos digitales del patrimonio bibliográfico de la Universidad de Córdoba.

Mostrando recursos 1 - 4 de 4

  1. Olive Actual “on Year” Yield Forecast Tool Based on the Tree Canopy Geometry Using UAS Imagery

    Sola Guirado, Rafael Rubén; Castillo-Ruiz, Francisco J.; Jiménez Jiménez, Francisco; Blanco Roldán, Gregorio L.; Castro García, Sergio; Gil Ribes, Jesús
    Olive has a notable importance in countries of Mediterranean basin and its profitability depends on several factors such as actual yield, production cost or product price. Actual “on year” Yield (AY) is production (kg tree-1) in “on years”, and this research attempts to relate it with geometrical parameters of the tree canopy. Regression equation to forecast AY based on manual canopy volume was determined based on data acquired from different orchard categories and cultivars during different harvesting seasons in southern Spain. Orthoimages were acquired with unmanned aerial systems (UAS) imagery calculating individual crown for relating to canopy volume and AY. Yield levels did not vary between orchard...
    (application/pdf) - 06-mar-2018

  2. Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect

    Castillo-Ruiz, Francisco J.; Castro García, Sergio; Blanco Roldán, Gregorio L.; Sola Guirado, Rafael Rubén; Gil Ribes, Jesús
    Crown porosity influences radiation interception, air movement through the fruit orchard, spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop an accurate and reliable methodology based on transmitted radiation measurements to assess the porosity of traditional olive trees under different pruning treatments. Transmitted radiation was employed as an indirect method to measure crown porosity in two olive orchards of the Picual and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to determine if the pruning system influences crown porosity. This study evaluated the accuracy and repeatability of four algorithms in measuring crown porosity under different solar zenith angles. From...
    (application/pdf) - 06-mar-2018

  3. Towards an Optimized Method of Olive Tree Crown Volume Measurement

    Miranda Fuentes, Antonio; Llorens, Jordi; Gamarra-Diezma, Juan Luis; Gil Moya, Emilio; Gil Ribes, Jesús
    Accurate crown characterization of large isolated olive trees is vital for adjusting spray doses in three-dimensional crop agriculture. Among the many methodologies available, laser sensors have proved to be the most reliable and accurate. However, their operation is time consuming and requires specialist knowledge and so a simpler crown characterization method is required. To this end, three methods were evaluated and compared with LiDAR measurements to determine their accuracy: Vertical Crown Projected Area method (VCPA), Ellipsoid Volume method (VE) and Tree Silhouette Volume method (VTS). Trials were performed in three different kinds of olive tree plantations: intensive, adapted one-trunked traditional and traditional. In total, 55 trees were characterized. Results...
    (application/pdf) - 06-mar-2018

  4. Frequency response of Valencia oranges to selective harvesting by vibration

    Castro García, Sergio; Blanco Roldán, Gregorio L.; Ferguson, Louis; Sánchez González, E.J.; Gil Ribes, Jesús
    Citrus mechanical harvesting has been investigated since the 1960’s. Even though mechanical harvesting could significantly lower production costs, the implementation by the private sector has been slow. The current harvesting technologies detach the fruits with trunk, canopy or branch vibration. For late-season sweet orange varieties which simultaneously bear mature fruit, immature fruitlets and flowers shaker harvesting decreases the subsequent year’s yield. This study, investigated the frequency response of mature fruits and immature fruitlets to determine the optimum frequency range for an efficient and selective harvest. Laboratory vibration transmission tests were conducted with 14 branches bearing 76 mature fruits and 151...
    (application/pdf) - 06-mar-2018

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