Abstract
A continuous measurement system of photosynthesis rate, transpiration rate and leaf temperature by means of open assimilation chamber system for single tobacco leaf, was developed.
Changes in photosynthesis rate, transpiration rate, leaf temperature of tobacco leaf in maturing stage, and soil moisture tension after irrigation, were investigated, and the following results were obtained.
In the case of irrigation at pF 2.72, photosynthesis rate and transpiration rate at 90 minutes after irrigation were higher and leaf temperature was lower than those of the initial state.
On the contrary, in the case of irrigation at pF 2.41, photosynthesis rate, transpiration rate and leaf temperature waved highly, and were almost same as initial state after 90 minutes.
There were significant correlations among changes in photosynthesis rate, transpiration rate and leaf temperature, but no relationship between soil moisture tension and other measurement.
After the irrigation, the sum of stomatal resistance and boundary layer resistance once increased and graduary became constant value.
The net mass of CO2 assimilated per unit mass of water transpired exprsssed per unit vapor pressure deficit was almost constant, 0.043 mb-1 at the dynamis stage after irrigation.
