Proceedings Of The Iiird Third International Symposium On Models For Plant Growth Environmental Control And Farm Management In Protected Cultivation Hortimodel2006

Plant architecture is a major determinant of the resource use efficiency of crops. The architecture of a plant shows ontogenetic structural changes which are modified by multiple environmental factors: Plant canopies are exposed to natural fluctuations in light quantity and the dynamically changing canopy architecture induces local variations in light quality. Changing temperature conditions or water availability during growth additionally affect plant architecture and thus crop productivity, because plants have various options to adapt their architecture to the available resources. Meeting the challenge of ensuring food security we must understand the plant’s mechanisms for integrating and responding to an orchestra of environmental factors. ‘Virtual plants’ describe plant architecture in silico. Virtual plants have the potential to help us understanding the complex feedback processes between canopy architecture, multiple environmental factors and crop productivity. As a research tool, they have become increasingly popular within the last decade due to their great power of realistically visualizing the plant’s architecture. This Research Topic highlights current research carried out on modeling plant architecture in changing environments.

A discussion of challenges related to the modeling and control of greenhouse crop growth, this book presents state-of-the-art answers to those challenges. The authors model the subsystems involved in successful greenhouse control using different techniques and show how the models obtained can be exploited for simulation or control design; they suggest ideas for the development of physical and/or black-box models for this purpose. Strategies for the control of climate- and irrigation-related variables are brought forward. The uses of PID control and feedforward compensators, both widely used in commercial tools, are summarized. The benefits of advanced control techniques—event-based, robust, and predictive control, for example—are used to improve on the performance of those basic methods. A hierarchical control architecture is developed governed by a high-level multiobjective optimization approach rather than traditional constrained optimization and artificial intelligence techniques. Reference trajectories are found for diurnal and nocturnal temperatures (climate-related setpoints) and electrical conductivity (fertirrigation-related setpoints). The objectives are to maximize profit, fruit quality, and water-use efficiency, these being encouraged by current international rules. Illustrative practical results selected from those obtained in an industrial greenhouse during the last eight years are shown and described. The text of the book is complemented by the use of illustrations, tables and real examples which are helpful in understanding the material. Modeling and Control of Greenhouse Crop Growth will be of interest to industrial engineers, academic researchers and graduates from agricultural, chemical, and process-control backgrounds.