Direct method of transpiration control in plant production processes

Abstract

A brief review of devices and methods of functioning of sensors for direct control of transpiration phenomena, their advantages and disadvantages are given. The task of the research is to experimentally confirm the selected calculation dependence for determining the values of xylem flow, i.e. to obtain a formula for determining the rate of xylem mass movement depending on the temperature gradient on the stem surface, which is measured by sensors and given to the system of digital control of production processes based on thermoregulation. And the higher the flow velocity, the faster the temperature front will reach the remote sensor and will cool down by a smaller value than at lower flow velocity and the temperature difference will have a smaller value. The dependence of xylem flow velocity (sap flow) q (g/s) on the temperature difference Δt of the coolant at the inlet of the stem system (heater) and at its outlet (remote sensor-thermocouple) was experimentally obtained. The obtained dependence agrees well with the hyperbolic function q = 0.15 / Δt, obtained by computational method, which confirms the possibility of its application in the processor of digital control of the system of productivity processes in plant systems.