Articles
RESPIRATION MEASUREMENTS AS A TOOL IN THE OPTIMIZATION OF PLANT ENVIRONMENT IN GLASSHOUSE CULTIVATION
Nevertheless respiration should not be considered as a wastefull process: it rather represents the process that supplies energy for growth and other vital processes in heterotrophic plant parts and, during darkness, in autotrophic plant parts as well.
Recently, on a basis of theoretical considerations and biochemical data, Penning de Vries managed to establish a quantitative relation between plant growth and respiration.
In models in which plant growth is calculated from photosynthesis this information, of course, is needed in order to obtain the net amount of carbon accumulated in the course of time.
The total amount of respiration consists of the sum of 3 different components: growth respiration, transport respiration and maintenance respiration.
Consequently, if it is possible to measure or to calculate maintenance and transport respiration, overall-respiration measurements can be used as a measure for growth rate.
Because fast and non-destructive methods exist, that can be used on whole plants as well as on attached plant parts, such measurements may provide a very valuable way of quantifying the short term growth reactions of the plant to the environment.
Such measurements are indispensable in the development of climate control systems that take into account the short-term interaction between plant and environment.
Using cucumber as an experimental crop, respiration measurements have been made on whole plants and on plant parts.
In this way the knowledge about the diurnal pattern of growth under various conditions has been improved.
This knowledge proved to be very important in the search for optimal night-temperature programmes.
Nevertheless, for a true optimization of the environment of the plant, besides short term effects on the diurnal carbon balance, the interrelations with long term effects on plant morphology and development have to be taken into account.