United States of AmericaCountry of destination:
Studying and understanding fruit quality and yield in fruit trees in response to irrigation and nitrogen status is a difficult endeavour. Trees are very complex organisms that are governed and influenced by multiple factors. Traditional experimental approaches to these problems are based on the study of a limited number of variables. Moreover, there are a large number of uncertainties and/or uncontrolled factors that make any observed response only representative of the specific conditions where that experiment took place. In many instances, confusion delays advance of knowledge and understanding only arises after many experiments under different conditions and seasons have been conducted. The integration of multiple variables at the whole-tree level, under different environmental conditions and over multiple years requires a modeling approach. A possible way to speed the progress in fruit quality and yield responses to irrigation and N management is by using computer-based crop models. These crop models can represent a conceptual platform in which many governing processes can be integrated and possible theoretical responses studied. This project is aimed towards developing functional-structural plant models (FSPM) that can be useful to study the impact of water management and nutritional status on fruit quality and yield. I develop these models on two representative deciduous species: Apple and Peach. I use the most recent models developed for these species to integrate knowledge and develop solutions for sustainable fruit production in a context of increasing ecological and climatic stresses.
My field of research is related to the study of dynamic systems with dynamic structures, such as growing plants. Most of my work aims at understanding the intricate relationship that exists between plant structure and their functioning. To that end, I use Functional Structural Plant Modeling, a highly interdisciplinary approach at the crossroad of mathematic, physic, ecophysiology and computer science. I did my PhD in the VirtualPlants team of UMR DAP in Montpellier under the joint supervision of Christophe Godin (INRIA) and Hervé Sinoquet (INRA). This work focused on the description and analysis of the multi-scale organisation of foliage using tools from fractal geometry, and the impact of such an organisation on light interception. Then, for my first postdoctoral fellowship, I joined the lab of Theodore DeJong at the University of California Davis to work on the LPeach model. LPeach is a functional-structural plant model of tree growth where all organs are considered as semi-autonomous components connected to each other and competing for resources. During that time, I mainly worked on linking the water stress effects on carbon partitioning by adding a xylem model to LPeach. I, then, generalized the LPeach framework to use it on Almond trees, and consequently developed the LAlmond model.
Picheny, V., Casadebaig, P., Trepos, R., Faivre, R., Da Silva, D., Vincourt, P., Costes, E, 2017. Using numerical plant models and phenotypic correlation space to design achievable ideotypes. Plant Cell and Environment, 40 (9), 1926-1939. Doi: 10.1111/pce.13001.
Davidson, A., Da Silva, D., DeJong, TM, 2017. The phyllochron of well-watered and water deficit mature peach trees varies with shoot type and vigour. Aob Plants, 9. Doi: 10.1093/aobpla/plx042.
Pallas, B., Da Silva, D., Valsesia, P., Yang, WW., Guillaume, O., Lauri, PE., Vercambre, G., Genard, M., Costes, E, 2016. Simulation of carbon allocation and organ growth variability in apple tree by connecting architectural and source-sink models. Annals of Botany, 118 (2), 317-330. Doi: 10.1093/aob/mcw085.
Da Silva, D., Qin, LC., DeBuse, C., DeJong, TM, 2014. Measuring and modelling seasonal patterns of carbohydrate storage and mobilization in the trunks and root crowns of peach trees. Annals of Botany, 114 (4), 643-652. Doi: 10.1093/aob/mcu033.
Da Silva, D., Han, LQ., Faivre, R., Costes, E, 2014. Influence of the variation of geometrical and topological traits on light interception efficiency of apple trees: sensitivity analysis and metamodelling for ideotype definition. Annals of Botany, 114 (4), 739-752. Doi: 10.1093/aob/mcu034.