ON LINE CO₂ ANALYSIS FOR THE DETERMINATION OF COLD TOLERANCE IN GREENHOUSE PLANTS USING A TEMPERATURE CONTROLLED LEAF CHAMBER

The still rising energy costs for heating greenhouses makes the development of a rapid screening procedure for cold tolerance among ornamental greenhouse species and cultivars of current interest.
Evenso an optimisation of culture conditions in terms of temperature requirements is of prime importance.

In order to study temperature effects on leaf photosynthesis and related plant growth processes, an on line temperature controlled leaf gas exchange system was build up.
The system consists of a modified ADC-Parkinson leaf chamber fitted with a peltier element, a programmable temperature control unit, an ADC-MK3 CO₂ analyser and a data processing unit.

It allows to monitor, continuously the net CO₂ uptake rate of a small leaflet subjected to a wide range of fluctuating temperature regimes (cooling to -5°C and a heating limit of +40°C).

A decline and recovery course of the net CO₂ uptake rate due to a given cold shock (a very fast 15 °C temperature fall) followed by a slow increase of temperature seems to be an adequate method for screening Bromelia cultivars for cold tolerance in less than one hour.

The usefullness of this screening procedure as applied to other ornamental greenhouse plants is now under investigation.

I International Workshop on Sensors in Horticulture

H. Huygens, P. Vandecasteele

Photosysnthesis, cold-tolerance, Cordyline, Vriesea

https://doi.org/10.17660/ActaHortic.1992.304.15