DEVELOPMENT OF PLANNING MODELS – METHODOLOGICAL ASPECTS

For several vegetable crops growth data have been collected from a series of experiments.
Planting or sowing dates were varied over the season and different temperature set points for the heating system chosen in order to break the strong interrelation between the factors light and temperature.
It was tried to keep cultivating as normal as possible which means trying to copy practical conditions of nurseries.

From growth measurements functions were fitted and mean growth rates of the period from sowing or planting until harvest derived.
Mean values of radiation and temperature were calculated from a climate data aquisition system with recordings in 1 minute intervals.
The relation between plant growth parameters and growth factors is described by a multiplicative function.

By using an iterative procedure the crop growth duration can be estimated.
Inputs are outside weather conditions, expected planting/sowing date and set point of the heating system.
With an additional submodel the energy demand is calculated, too.

International Symposium on Models for Plant Growth, Environmental Control and Farm Management in Protected Cultivation

H.-P. Liebig

https://doi.org/10.17660/ActaHortic.1989.248.17