EVALUATION OF COMBINED APPLICATION OF FOG SYSTEM AND CO₂ ENRICHMENT IN GREENHOUSES BY USING PHYTOMONITORING DATA

A two-stage experiment was performed to determine the influence of a high-pressure fog system on the CO₂ concentration and gas exchange efficiency (GEE) in greenhouses with CO₂ enrichment.
The experiments were carried out with tomatoes (Lycopersicon esculentum). Photosynthetic GEE was introduced as a new evaluative quantity to represent the short-term CO₂ uptake capacity of the plant canopy.
The physiological data for the plants were measured with a phytomonitoring system.
The ratio between the measured and the calculated CO₂ uptake GEE was calculated and coded on a color scale.
With the Mollier plot method, ranges with a maximum GEE can be located for several temperatures and relative humidities.
Plant yields and quality were also recorded.
A preliminary test identified an increase in GEE with higher relative humidity, with a dependence on leaf transpiration (r^² = 0.56). In the main experiment, the effects of the combined application of fog and CO₂ enrichment were estimated.
A higher diurnal average CO₂ content was observed in the fog cabin.
This was induced by the cooling effect of the fog and the associated smaller ventilation openings.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

U. Schmidt, C. Huber, T. Rocksch

relative humidity, ventilation, gas exchange efficiency, greenhouse cooling, tomato

https://doi.org/10.17660/ActaHortic.2008.801.159