Transpiration of maize in a pannonian climate

vegetation. Therefore, an experiment on separating the components of evapotranspiration was carried out at the lysimeterstation in Gros-Enzersdorf, Austria. A lysimeter with soil water content probes was used to determine evapotranspiration. Furthermore, sap flow measurements were done in order to determine the transpiration rate of the planted maize. In this regard, the heat ratio method was applied, measuring the sap velocity within the plant using a short pulse of heat as a tracer. Therefore, sensor sets containing a heater needle and two temperature probes were installed in three maize stems. Multiplication of the gained sap velocity and the cross sectional area of the stem delivered the flow volume per plant. The number of plants as well as the surface area was well defined; hence, the transpiration rate of the maize on the lysimeter could be calculated. Evapotranspiration was calculated from the water balance equation, knowing soil water change and percolation water from lysimeter measurements. Results will be shown.