Integration of explanatory and empirical crop models for greenhouse management support

In the management of greenhouse nurseries the grower has to deal with compl ex dynamic optimisation problems. In many of these problems the behaviour o f crops is an important issue. Crop models, that formalise our knowledge ab out the crop, could thus be an important element of management tools in hor ticultural practice, but their role has been quite limited up till now. Yet , it is likely that such tools will become more important and that their im plementation in future management tools will become more feasible than befo re. An important role for such model based support systems will be in the desig n, evaluation and adaptation of cultivation schedules (blueprints). Models that are able to deal with such complex problems are built of many sub-mode ls, because they have to cover the full problem domain, to provide useful a nswers. Relevant sub-models could be arranged in a parallel structure, wher e they sub run basically independent of each other, using the same inputs. Alternatively, output of (photosynthesis based) sub-models could provide in put to other sub-models. For many applications it is in fact irrelevant wha t the source of information provided to a decision maker or an automated co ntrol system is, as long as the information is sufficient, correctness and reliability of the information are convincing, and basic functions of good DSS are provided.