QualiTree, a virtual fruit tree to study the management of fruit quality. II. Parameterisation for peach, analysis of growth-related processes and agronomic scenarios

Abstract

In this paper, QualiTree, a fruit tree model designed to study the management of fruit quality, and developed and described in a companion paper (Lescourret et al. in Trees Struct Funct, 2010), was combined with a simple light-interception sub-model, and then parameterised and tested on peach in different situations. Simulation outputs displayed fairly good agreement with the observed data concerning mean fruit and vegetative growth. The variability over time of fruit and vegetative growth was well predicted. QualiTree was able to reproduce the observed response of trees to heterogeneous thinning treatments in terms of fruit growth. A sensitivity analysis showed that the average seasonal growth rates of the different organs were sensitive to changes to the values of their respective initial relative growth rates and that stem wood was the tree organ the most affected by a change in the initial relative growth rates of other organs. QualiTree was able to react to simulated scenarios that combined thinning and pest attacks. As expected, thinning intensity and the percentage damage caused by pests significantly affected fruit yield and quality traits at harvest. These simulations showed that QualiTree could be a useful tool to design innovative horticultural practices.

Light interception efficiency analysis based on three-dimensional peach canopy models

“…3D tree models have been used to simulate the photosynthesis of peaches according to the amount of direct and diffuse radiation (Génard et al, 2000). QualiTree integrates simple light interception and physiological process models to help design innovative horticultural best practices (Mirás-Avalos et al, 2011).…”

Assessment of the viability of using saline reclaimed water in grapefruit in medium to long term

“…Tolerance may decline due to progressive toxic levels of Na, Cl and B that have accumulated in leaves (Reboll et al, 2000;Pereira et al, 2010). Knowledge of the role that leaf phenology, structure, photosynthetic function and plant water play in physiological function, and their interactions during the growing season, is important for assessing the productivity of fruit tree orchards (Mirás-Ávalos et al, 2011) and for characterizing the impact of agronomic practices.…”

Gestión de la calidad del fruto mediante prácticas culturales y aplicación de un modelo fisiológico en melocotonero

“…Regarding to the parameterisation results for both peach cultivars, we can emphasize the values of the parameter expressing the effect of distance between tree objects on carbon exchange within the tree (k) (Lescourret et al, 2011). This parameter is cultivardependent, and the values showed for our cultivars were quite low (k=0.008 and k=0.002 for "Flordastar" and "Catherine"), indicating that within-tree distances were not limiting in any of the two varieties studied, as was observed for "Alexandra" and "Suncrest" (Mirás-Avalos et al, 2011). The remaining cultivar-dependent parameters estimated provided good results in both peach cultivars.…”

“…Otro aspecto interesante a la hora de modelizar un cultivo leñoso es el de implementar la intercepción de la radiación solar por parte del dosel vegetal, ya que el comportamiento de este tipo de plantaciones es totalmente diferente al de los cultivos extensivos en los que teniendo en cuenta un coeficiente de extinción y el porcentaje de cobertura se puede obtener una buena estimación de la radiación interceptada (Mirás-Avalos et. al, 2011).…”

“…Resumen "Flordastar" y "Catherine", respectivamente). Esto sugiere que las distancias entre los distintos órganos del árbol no resultaron limitantes para los flujos de carbono en ninguna de las dos variedades estudiadas, al igual que ocurría con las variedades previamente descritas en la literatura, "Alexandra" y "Suncrest" (Mirás-Avalos et al, 2011). La estimación de los parámetros dependientes del cultivar se realizó con éxito en ambas variedades, ya que los valores simulados se ajustaron adecuadamente a los observados, tanto para los valores de crecimiento vegetativo y reproductivo, como para el contenido en azúcares, este último en la variedad "Catherine".…”