MODELLING OF STOMATAL CONDUCTANCE AS A VARIABLE FOR ENVIRONMENTAL CONTROL IN GREENHOUSES

A combination of a transmitted-light microscope and a video camera was used for monitoring the movement of stomata of bean leaves.
A newly developed gas exchange measuring system was used for calculating the stomatal conductance.
The variation of the conductance was compared with the movement of the stomata.
Good agreement was found between stomatal conductance and the observed movement of the stomata when microclimate changed slowly.
Strong variations of the vapour concentration differences resulted in oscillations of stomatal conductance that were not observed with the visual methods.
Subsequent dynamic adjustment of stomatal conductance using a sliding mean yielded close correlations between stomatal conductance and net photosynthesis in greenhouse experiments with tomato plants.

IV International Symposium on Models for Plant Growth and Control in Greenhouses: Modeling for the 21st Century – Agronomic and Greenhouse Crop Models

U. Schmidt

stomata movements, stomatal conductance, photosynthesis, transpiration, vapour pressure difference, stomata dynamics

https://doi.org/10.17660/ActaHortic.2002.593.29