GROWTH MODELS AS AN AID FOR PLANNING VEGETABLE PRODUCTION IN GREENHOUSES

ISHS Acta Horticulturae 260: International Symposium on Growth and Yield Control in Vegetable Production

GROWTH MODELS AS AN AID FOR PLANNING VEGETABLE PRODUCTION IN GREENHOUSES

Author:

H. Krug

Abstract:
In Hannover the development of growth models to improve planning and control of greenhouse production according to the rapidly changing economic conditions, especially the prices of input factors, started with the energy crisis in the early seventies.

Regarding the objections we distinguish two approaches:

models for production planning considering long term reactions of plants to growth factors to derive parameters for long term planning and
models for production control to consider short term reactions in the range of days, hours or minutes, to react to changes in the environment or to correct set points

This distinction results from our considerations and experiences of the efficiency of these two approaches. If it becomes possible to simulate growth and development on the base of the underlying basic processes with high accuracy - this is the aim of many teams - this approach will accomplish all needs. Considering the number of crops to be modelled to optimize crop rotations we doubt, however, that this goal can be reached in the near future. Therefore, we started with a simpler approach, the description of long term growth processes at high abstraction level using regression functions. Later on we tried to derive short term reactions (see paper of Liebig).

The procedure of the long term approach is described in figure 1 (see Krug and Liebig 1979 a, b, 1984, 1988).

Full Text (PDF format, 249256 bytes)
Citation

Download Adobe Acrobat Reader (free software to read PDF files)