ISHS Acta Horticulturae 107: Optimalisation of Plant Growth under Protected Cultivation through Microclimate Control
A DESCRIPTIVE PRODUCTION MODEL AS A TOOL FOR OPTIMIZING PLANT PRODUCTION |
| Author: | H. Krug |
| Abstract:
It es generally accepted, that models are a useful tool to analyse the complex system "crop production". Models can be constructed on the base of single physiological and morphogenetical processes, which have to be composed to physiological dynamical growth models. Since a numerous number of processes is involved and many of them are neither fully understood nor quantified, it may take many decades to construct growth models to simulate crop growth under horticultural growing conditions. Single experiments in practice conditions, on the other hand, allow only regional and temporary statements and are of minor importance for general recommendations. Therefore we developed another approach to analyse crop production (Krug und Liebig, 1979 a und b). We do not start our research with single basic processes, but with reactions of complete crops or their organs of interest (fruits, tubers, etc.). The crops are cultivated in practice like conditions, to avoid errors of transferability. For years many sets during the season with different temperature regimes gave numerous data. Using a descriptive growth model, these data enable to relate crop growth to the main climatic growth factors (radiation and temperature) and production procedures (time of planting or harvesting, temperature control in the greenhouses). Until now, the data are calculated for the period from emergence or planting to harvest. For these periods the heating costs (data of Vickermann) and the yields, both as a function of the set points and the season, are calculated. The yields multiplied by the product prices (average prices of German producer markets) give the output. The outputs minus the heating costs are a valuable criterion of the profitability of production procedures or the crops. These data can also be used as a base for calculating profitable crop rotations with the linear programming method. | |
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