RANGES OF PRIMARY ENVIRONMENTAL EFFECTS ON PLANTS
Some of the underlying principles of the results were presented earlier*.
For various sets of conditions, met in glasshouse culture and in climate rooms, the relative importance of factors as:
- absorbed short wave radiation and heat radiation,
- vapour pressure deficit of the air,
- boundary layer resistance in the air around the leaf,
- stomatal resistance of the leaf,
is discussed for:
- the range of transpiration, leaf temperature and photosynthesis obtainable,
- the effect of changes in each of the conditions mentioned on the changes in transpiration, leaf temperature, and photosynthesis,
- the value of the transpiration coefficient.
From the results can be derived, e. g. for a given flux of radiation absorbed, which parameters are most important for the control of transpiration, leaf temperature and photosynthesis.