Crop modelling in horticulture: state of the art

For the last two decades, crop modelling has become a major research tool in horticulture as in other areas of plant production. A reason for such a success is the versatility of this technique. Scientists look for conceptual frameworks, and horticulture has offered original case studies on, e.g. photosynthesis or plant architecture. Engineers want procedures to solve practical problems, and horticulture is a field where yield prediction, policy evaluation or process optimisation can be very important. Horticulture is characterised by a high diversity of cultivation systems and fruit, vegetable and ornamental species. Till now, few of them have been modelled and efforts have focused on a limited number of processes of crop growth and development. The water balance of plants, the uptake of minerals, the interaction with pests, diseases and genetics, the interplant variability, and the formation of product quality have been poorly addressed. To face the challenge of diversity, modellers will certainly have to adopt more generic approaches. For decision making, crop models should be integrated in a model of the whole system under control and connected to a model of the decision system. Even though a lot remains to be done, a major achievement of crop modelling in horticulture has been a significant increase of communication tin terms of concepts and modelling tools) in a field where the high diversity of species and cultivation systems can be an obstacle. (C) 1998 Elsevier Science B.V.