Relations between leaf resistance, CO2-concentration and CO2-assimilation in maize, beans, Lalang grass and sunflower
Year: 1978
Type: other
Abstract: Theoretical considerations concern the relations between leaf resistances for C0 2 and water vapour, leaf transpiration, net C0 2 -assimilation and external and internal COrconcentrations.Experiments with maize, beans and lalang grass show that the stomatal conductivity can be described as controlled by the COrconcentration in the stomatal cavity and consequently by the rate of C0 2 -uptake.At external C0 2 -concentrations below 300 vpm the internal COrconcentration is proportional to the external concentration, but above 300 vpm it no longer rises.In some cases the regulation disappears and in sunflower no regulation was found at all.Because of this, the C0 2 -assimilation in sunflower responds more to external C0 2 than in maize and beans, but sunflower has also a less efficient water use.Maize uses water more efficiently than beans, because it has a lower setpoint for the internal C0 2 -concentration.When regulation is present, stomatal conductivity is best calculated as a function of net COrassimilation and the setpoint for internal COrconcentration.
Authors: J. Goudriaan, H.H. van Laar
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1587368339