ON-LINE ACQUISITION OF TRANSPIRATION AS A BASIS FOR ECOLOGICAL PROCESS CONTROL IN GREENHOUSES

While process control in greenhouses has so far been concerned with better yields and higher quality of vegetables and ornamental plants it will increasingly have to meet ecological requirements in future.
In greenhouse crop production this involves especially the creation of closed energy and material cycles.

As a rule, the amount of energy and auxiliary materials supplied into the production process (such as water, fertilizers, plant protectives) should not exceed the amount required for the plants metabolism and energy turnover.
To meet this demand it is essential to determine energy and material requirement both in the long run (e.g. by yield models) and on line.
A decisive prerequisite for this way of consumption control is the use of measured values that indicate the development of the plants and serve as feedback signals for the optimizing process.
Whereas long-term consumption planning mainly relies on such measured values as yield increase and quality development there are practically no data available for a direct and short-term process control.
Deficient supply of the plants with water, energy and fertilizer often becomes evident in low yields.

Excessive nutrition, however, can only be detected after several years when there are environmental damages.

I International Workshop on Sensors in Horticulture

U. Schmidt

https://doi.org/10.17660/ActaHortic.1992.304.41