ISHS Acta Horticulturae 156: XII Working Party on Greenhouse Cucumbers
EFFECT OF MAINTENANCE RESPIRATION ON GROWTH AND DEVELOPMENT OF A CLOSED CANOPY |
| Author: | A.H.C.M. Schapendonk |
| Abstract:
The use of assimilated carbon for the maintenance of the functional plant structure is a significant factor in crop growth. The most important maintenance process is the turn-over of proteins, though some other energy-consuming processes like active transport of ions should be considered. The impact of maintenance respiration increases when the ratio between growth and the amount of biomass decreases. Two situations may be considered:
An experiment was done to measure the protein content of cucumber leaves at 3 different temperatures and two light intensities. Individual leaves were harvested at different time intervals from the moment that they were fully expanded. The observed decrease of the protein content appeared to be the result of dilution by non-degradable components and by actual protein break-down. In a closed canopy, the absolute amount of protein will be determined by the synthesis of new proteins in young leaves and the breakdown of proteins in ageing leaves. When maintenance respiration is expressed on basis of the amount of protein it will be determined by the relative contribution of both processes. A model is developed that calculates the maintenance respiration of the crop under different environmental conditions and its effect on plant growth. | |
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