Articles
A STRATEGY FOR CLIMATE CONTROL IN GREENHOUSES IN EARLY WINTER PRODUCTION
Furthermore, it has been demonstrated, that the plant is a self-controlling system, in which the balance between growth and photosynthesis is maintained under a wide range of environmental conditions.
Consequently the problem of optimization of temperature in greenhouse cultivation in early winter may be reduced to an economic weighing of the additional profits of earliness against extra fuel costs.
For this optimization, the effect of temperature, in combination with other environmental conditions, on earliness, thus has to be quantified.
Using data from the literature, we attempted, as a first approximation, to relate earliness to temperature and light, assuming that the number of leaves on the plant is determining the start of the production phase.
On the basis of this relation, optimum temperatures were calculated at different light intensities, for an early winter cucumber crop, using average values for the price of fruits and for heating costs.
Although some of the assumptions made need further confirmation and possibly have to be changed, some general conclusions on optimization of temperature control may nevertheless be drawn.
In this strategy besides technological knowledge, economical and physiological knowledge are also incorporated.
This provides us with a sound basis for the long- and short-term optimization of temperature control.